Protein factors that promote the exchange of GTP for GDP bound to GTP-BINDING PROTEINS.
An enzyme that catalyzes the deamination of guanine to form xanthine. EC 3.5.4.3.
Guanosine 5'-(tetrahydrogen triphosphate). A guanine nucleotide containing three phosphate groups esterified to the sugar moiety.
Signaling proteins which function as master molecular switches by activating Rho GTPases through conversion of guanine nucleotides. Rho GTPases in turn control many aspects of cell behavior through the regulation of multiple downstream signal transduction pathways.
A guanine nucleotide containing two phosphate groups esterified to the sugar moiety.
Regulatory proteins that act as molecular switches. They control a wide range of biological processes including: receptor signaling, intracellular signal transduction pathways, and protein synthesis. Their activity is regulated by factors that control their ability to bind to and hydrolyze GTP to GDP. EC 3.6.1.-.
A family of GUANINE NUCLEOTIDE EXCHANGE FACTORS that are specific for RAS PROTEINS.
A non-hydrolyzable analog of GTP, in which the oxygen atom bridging the beta to the gamma phosphate is replaced by a nitrogen atom. It binds tightly to G-protein in the presence of Mg2+. The nucleotide is a potent stimulator of ADENYLYL CYCLASES.
Guanosine 5'-(trihydrogen diphosphate), monoanhydride with phosphorothioic acid. A stable GTP analog which enjoys a variety of physiological actions such as stimulation of guanine nucleotide-binding proteins, phosphoinositide hydrolysis, cyclic AMP accumulation, and activation of specific proto-oncogenes.
A purine nucleoside that has guanine linked by its N9 nitrogen to the C1 carbon of ribose. It is a component of ribonucleic acid and its nucleotides play important roles in metabolism. (From Dorland, 28th ed)
A guanine nucleotide containing one phosphate group esterified to the sugar moiety and found widely in nature.
Protein factors that inhibit the dissociation of GDP from GTP-BINDING PROTEINS.
A pyrimidine base that is a fundamental unit of nucleic acids.
Nucleotides in which the base moiety is substituted with one or more sulfur atoms.
Descriptions of specific amino acid, carbohydrate, or nucleotide sequences which have appeared in the published literature and/or are deposited in and maintained by databanks such as GENBANK, European Molecular Biology Laboratory (EMBL), National Biomedical Research Foundation (NBRF), or other sequence repositories.
A 145-kDa guanine nucleotide exchange factor that is specific for rap1 and ras GTP-BINDING PROTEINS. It associates with SH3 domains of the crk family of signaling proteins.
MONOMERIC GTP-BINDING PROTEINS that were initially recognized as allosteric activators of the MONO(ADP-RIBOSE) TRANSFERASE of the CHOLERA TOXIN catalytic subunit. They are involved in vesicle trafficking and activation of PHOSPHOLIPASE D. This enzyme was formerly listed as EC 3.6.1.47
A purine base and a fundamental unit of ADENINE NUCLEOTIDES.
A deoxyribonucleotide polymer that is the primary genetic material of all cells. Eukaryotic and prokaryotic organisms normally contain DNA in a double-stranded state, yet several important biological processes transiently involve single-stranded regions. DNA, which consists of a polysugar-phosphate backbone possessing projections of purines (adenine and guanine) and pyrimidines (thymine and cytosine), forms a double helix that is held together by hydrogen bonds between these purines and pyrimidines (adenine to thymine and guanine to cytosine).
Enzymes that hydrolyze GTP to GDP. EC 3.6.1.-.
An enzyme that catalyzes the conversion of 5-phosphoribosyl-1-pyrophosphate and hypoxanthine, guanine, or 6-mercaptopurine to the corresponding 5'-mononucleotides and pyrophosphate. The enzyme is important in purine biosynthesis as well as central nervous system functions. Complete lack of enzyme activity is associated with the LESCH-NYHAN SYNDROME, while partial deficiency results in overproduction of uric acid. EC 2.4.2.8.
The rate dynamics in chemical or physical systems.
The sequence of PURINES and PYRIMIDINES in nucleic acids and polynucleotides. It is also called nucleotide sequence.
The products of chemical reactions that result in the addition of extraneous chemical groups to DNA.
A set of BACTERIAL ADHESINS and TOXINS, BIOLOGICAL produced by BORDETELLA organisms that determine the pathogenesis of BORDETELLA INFECTIONS, such as WHOOPING COUGH. They include filamentous hemagglutinin; FIMBRIAE PROTEINS; pertactin; PERTUSSIS TOXIN; ADENYLATE CYCLASE TOXIN; dermonecrotic toxin; tracheal cytotoxin; Bordetella LIPOPOLYSACCHARIDES; and tracheal colonization factor.
An enzyme that catalyzes the dehydrogenation of inosine 5'-phosphate to xanthosine 5'-phosphate in the presence of NAD. EC 1.1.1.205.
Proto-oncogene proteins that are guanine nucleotide exchange factors for RHO GTPASES. They also function as signal transducing adaptor proteins.
An enzyme of the lyase class that catalyzes the formation of CYCLIC AMP and pyrophosphate from ATP. EC 4.6.1.1.
One of the virulence factors produced by BORDETELLA PERTUSSIS. It is a multimeric protein composed of five subunits S1 - S5. S1 contains mono ADPribose transferase activity.
A nucleoside consisting of the base guanine and the sugar deoxyribose.
One of the early purine analogs showing antineoplastic activity. It functions as an antimetabolite and is easily incorporated into ribonucleic acids.
A guanine nucleotide exchange factor that is expressed primarily in neuronal tissue and may be specific for the Ha-ras homolog of the RAS PROTEINS.
A guanine nucleotide exchange factor that stimulates the dissociation of GDP from RAL GTP-BINDING PROTEINS. It also has GDP exchange activity towards other MONOMERIC GTP-BINDING PROTEINS.
A series of heterocyclic compounds that are variously substituted in nature and are known also as purine bases. They include ADENINE and GUANINE, constituents of nucleic acids, as well as many alkaloids such as CAFFEINE and THEOPHYLLINE. Uric acid is the metabolic end product of purine metabolism.
A member of the Rho family of MONOMERIC GTP-BINDING PROTEINS. It is associated with a diverse array of cellular functions including cytoskeletal changes, filopodia formation and transport through the GOLGI APPARATUS. This enzyme was formerly listed as EC 3.6.1.47.
An ester formed between the aldehydic carbon of RIBOSE and the terminal phosphate of ADENOSINE DIPHOSPHATE. It is produced by the hydrolysis of nicotinamide-adenine dinucleotide (NAD) by a variety of enzymes, some of which transfer an ADP-ribosyl group to target proteins.
The order of amino acids as they occur in a polypeptide chain. This is referred to as the primary structure of proteins. It is of fundamental importance in determining PROTEIN CONFORMATION.
ADP-RIBOSYLATION FACTOR 1 is involved in regulating intracellular transport by modulating the interaction of coat proteins with organelle membranes in the early secretory pathway. It is a component of COAT PROTEIN COMPLEX I. This enzyme was formerly listed as EC 3.6.1.47.
Purine bases related to hypoxanthine, an intermediate product of uric acid synthesis and a breakdown product of adenine catabolism.
A rac GTP-binding protein involved in regulating actin filaments at the plasma membrane. It controls the development of filopodia and lamellipodia in cells and thereby influences cellular motility and adhesion. It is also involved in activation of NADPH OXIDASE. This enzyme was formerly listed as EC 3.6.1.47.
A large family of MONOMERIC GTP-BINDING PROTEINS that are involved in regulation of actin organization, gene expression and cell cycle progression. This enzyme was formerly listed as EC 3.6.1.47.
The spatial arrangement of the atoms of a nucleic acid or polynucleotide that results in its characteristic 3-dimensional shape.
A RHO GTP-BINDING PROTEIN involved in regulating signal transduction pathways that control assembly of focal adhesions and actin stress fibers. This enzyme was formerly listed as EC 3.6.1.47.
The process in which substances, either endogenous or exogenous, bind to proteins, peptides, enzymes, protein precursors, or allied compounds. Specific protein-binding measures are often used as assays in diagnostic assessments.
One of the virulence factors produced by virulent BORDETELLA organisms. It is a bifunctional protein with both ADENYLYL CYCLASES and hemolysin components.
Proteins that activate the GTPase of specific GTP-BINDING PROTEINS.
Enzymes of the transferase class that catalyze the transfer of a pentose group from one compound to another.
A sub-family of RHO GTP-BINDING PROTEINS that is involved in regulating the organization of cytoskeletal filaments. This enzyme was formerly listed as EC 3.6.1.47.
A source of inorganic fluoride which is used topically to prevent dental caries.
Any detectable and heritable change in the genetic material that causes a change in the GENOTYPE and which is transmitted to daughter cells and to succeeding generations.
The covalent bonding of an alkyl group to an organic compound. It can occur by a simple addition reaction or by substitution of another functional group.
A GUANOSINE analog that acts as an antimetabolite. Viruses are especially susceptible. Used especially against herpes.
The lipid- and protein-containing, selectively permeable membrane that surrounds the cytoplasm in prokaryotic and eukaryotic cells.
Higher-order DNA and RNA structures formed from guanine-rich sequences. They are formed around a core of at least 2 stacked tetrads of hydrogen-bonded GUANINE bases. They can be formed from one two or four separate strands of DNA (or RNA) and can display a wide variety of topologies, which are a consequence of various combinations of strand direction, length, and sequence. (From Nucleic Acids Res. 2006;34(19):5402-15)
A subcategory of guanine nucleotide dissociation inhibitors that are specific for RHO GTP-BINDING PROTEINS.
The parts of a macromolecule that directly participate in its specific combination with another molecule.
Established cell cultures that have the potential to propagate indefinitely.
Guanine nucleotides which contain deoxyribose as the sugar moiety.
An ENTEROTOXIN from VIBRIO CHOLERAE. It consists of two major protomers, the heavy (H) or A subunit and the B protomer which consists of 5 light (L) or B subunits. The catalytic A subunit is proteolytically cleaved into fragments A1 and A2. The A1 fragment is a MONO(ADP-RIBOSE) TRANSFERASE. The B protomer binds cholera toxin to intestinal epithelial cells, and facilitates the uptake of the A1 fragment. The A1 catalyzed transfer of ADP-RIBOSE to the alpha subunits of heterotrimeric G PROTEINS activates the production of CYCLIC AMP. Increased levels of cyclic AMP are thought to modulate release of fluid and electrolytes from intestinal crypt cells.
A genetically related subfamily of RAP GTP-BINDING PROTEINS that share homology with RAS PROTEINS. They bind to Ras effectors but do not activate them, therefore they may antagonize the effects of RAS PROTEINS. This enzyme was formerly listed as EC 3.6.1.47.
A family of MONOMERIC GTP-BINDING PROTEINS that are related to RAS PROTEINS.This enzyme was formerly listed as EC 3.6.1.47.
Models used experimentally or theoretically to study molecular shape, electronic properties, or interactions; includes analogous molecules, computer-generated graphics, and mechanical structures.
The intracellular transfer of information (biological activation/inhibition) through a signal pathway. In each signal transduction system, an activation/inhibition signal from a biologically active molecule (hormone, neurotransmitter) is mediated via the coupling of a receptor/enzyme to a second messenger system or to an ion channel. Signal transduction plays an important role in activating cellular functions, cell differentiation, and cell proliferation. Examples of signal transduction systems are the GAMMA-AMINOBUTYRIC ACID-postsynaptic receptor-calcium ion channel system, the receptor-mediated T-cell activation pathway, and the receptor-mediated activation of phospholipases. Those coupled to membrane depolarization or intracellular release of calcium include the receptor-mediated activation of cytotoxic functions in granulocytes and the synaptic potentiation of protein kinase activation. Some signal transduction pathways may be part of larger signal transduction pathways; for example, protein kinase activation is part of the platelet activation signal pathway.
A mammalian homolog of the DROSOPHILA SON OF SEVENLESS PROTEIN. It is a guanine nucleotide exchange factor for RAS PROTEINS.
The level of protein structure in which combinations of secondary protein structures (alpha helices, beta sheets, loop regions, and motifs) pack together to form folded shapes called domains. Disulfide bridges between cysteines in two different parts of the polypeptide chain along with other interactions between the chains play a role in the formation and stabilization of tertiary structure. Small proteins usually consist of only one domain but larger proteins may contain a number of domains connected by segments of polypeptide chain which lack regular secondary structure.
Pairing of purine and pyrimidine bases by HYDROGEN BONDING in double-stranded DNA or RNA.
A group of deoxyribonucleotides (up to 12) in which the phosphate residues of each deoxyribonucleotide act as bridges in forming diester linkages between the deoxyribose moieties.
Conversion of an inactive form of an enzyme to one possessing metabolic activity. It includes 1, activation by ions (activators); 2, activation by cofactors (coenzymes); and 3, conversion of an enzyme precursor (proenzyme or zymogen) to an active enzyme.
A species of gram-negative, facultatively anaerobic, rod-shaped bacteria (GRAM-NEGATIVE FACULTATIVELY ANAEROBIC RODS) commonly found in the lower part of the intestine of warm-blooded animals. It is usually nonpathogenic, but some strains are known to produce DIARRHEA and pyogenic infections. Pathogenic strains (virotypes) are classified by their specific pathogenic mechanisms such as toxins (ENTEROTOXIGENIC ESCHERICHIA COLI), etc.
Cellular proteins encoded by the H-ras, K-ras and N-ras genes. The proteins have GTPase activity and are involved in signal transduction as monomeric GTP-binding proteins. Elevated levels of p21 c-ras have been associated with neoplasia. This enzyme was formerly listed as EC 3.6.1.47.
Purines attached to a RIBOSE and a phosphate that can polymerize to form DNA and RNA.
Polymers made up of a few (2-20) nucleotides. In molecular genetics, they refer to a short sequence synthesized to match a region where a mutation is known to occur, and then used as a probe (OLIGONUCLEOTIDE PROBES). (Dorland, 28th ed)
Small, monomeric GTP-binding proteins encoded by ras genes (GENES, RAS). The protooncogene-derived protein, PROTO-ONCOGENE PROTEIN P21(RAS), plays a role in normal cellular growth, differentiation and development. The oncogene-derived protein (ONCOGENE PROTEIN P21(RAS)) can play a role in aberrant cellular regulation during neoplastic cell transformation (CELL TRANSFORMATION, NEOPLASTIC). This enzyme was formerly listed as EC 3.6.1.47.
A potent hepatotoxic and hepatocarcinogenic mycotoxin produced by the Aspergillus flavus group of fungi. It is also mutagenic, teratogenic, and causes immunosuppression in animals. It is found as a contaminant in peanuts, cottonseed meal, corn, and other grains. The mycotoxin requires epoxidation to aflatoxin B1 2,3-oxide for activation. Microsomal monooxygenases biotransform the toxin to the less toxic metabolites aflatoxin M1 and Q1.
A guanine nucleotide exchange factor that acts to restore EUKARYOTIC INITIATION FACTOR-2 to its GTP bound form.
An abundantly-expressed rho GDP-dissociation inhibitor subtype that regulates a broad variety of RHO GTPASES.
The monomeric units from which DNA or RNA polymers are constructed. They consist of a purine or pyrimidine base, a pentose sugar, and a phosphate group. (From King & Stansfield, A Dictionary of Genetics, 4th ed)
A heterotrimeric GTP-binding protein that mediates the light activation signal from photolyzed rhodopsin to cyclic GMP phosphodiesterase and is pivotal in the visual excitation process. Activation of rhodopsin on the outer membrane of rod and cone cells causes GTP to bind to transducin followed by dissociation of the alpha subunit-GTP complex from the beta/gamma subunits of transducin. The alpha subunit-GTP complex activates the cyclic GMP phosphodiesterase which catalyzes the hydrolysis of cyclic GMP to 5'-GMP. This leads to closure of the sodium and calcium channels and therefore hyperpolarization of the rod cells. EC 3.6.1.-.
2-Amino-1,5-dihydro-4,6-pteridinedione. Pigment first discovered in butterfly wings and widely distributed in plants and animals.
A family of ubiquitously expressed MONOMERIC GTP-BINDING PROTEINS that are involved in intracellular signal transduction. This enzyme was formerly listed as EC 3.6.1.47.
Purines with a RIBOSE attached that can be phosphorylated to PURINE NUCLEOTIDES.
Domesticated bovine animals of the genus Bos, usually kept on a farm or ranch and used for the production of meat or dairy products or for heavy labor.
A metallic element that has the atomic symbol Mg, atomic number 12, and atomic weight 24.31. It is important for the activity of many enzymes, especially those involved in OXIDATIVE PHOSPHORYLATION.
A large family of MONOMERIC GTP-BINDING PROTEINS that play a key role in cellular secretory and endocytic pathways. EC 3.6.1.-.
Linear POLYPEPTIDES that are synthesized on RIBOSOMES and may be further modified, crosslinked, cleaved, or assembled into complex proteins with several subunits. The specific sequence of AMINO ACIDS determines the shape the polypeptide will take, during PROTEIN FOLDING, and the function of the protein.
A purine base found in most body tissues and fluids, certain plants, and some urinary calculi. It is an intermediate in the degradation of adenosine monophosphate to uric acid, being formed by oxidation of hypoxanthine. The methylated xanthine compounds caffeine, theobromine, and theophylline and their derivatives are used in medicine for their bronchodilator effects. (Dorland, 28th ed)
Inorganic compounds that contain aluminum as an integral part of the molecule.
The degree of similarity between sequences of amino acids. This information is useful for the analyzing genetic relatedness of proteins and species.
Purine or pyrimidine bases attached to a ribose or deoxyribose. (From King & Stansfield, A Dictionary of Genetics, 4th ed)
The relationship between the chemical structure of a compound and its biological or pharmacological activity. Compounds are often classed together because they have structural characteristics in common including shape, size, stereochemical arrangement, and distribution of functional groups.
Esters formed between the aldehydic carbon of sugars and the terminal phosphate of guanosine diphosphate.
Proteins prepared by recombinant DNA technology.
A class of enzymes involved in the hydrolysis of the N-glycosidic bond of nitrogen-linked sugars.
A characteristic feature of enzyme activity in relation to the kind of substrate on which the enzyme or catalytic molecule reacts.
The insertion of recombinant DNA molecules from prokaryotic and/or eukaryotic sources into a replicating vehicle, such as a plasmid or virus vector, and the introduction of the resultant hybrid molecules into recipient cells without altering the viability of those cells.
An enzyme that transfers methyl groups from O(6)-methylguanine, and other methylated moieties of DNA, to a cysteine residue in itself, thus repairing alkylated DNA in a single-step reaction. EC 2.1.1.63.
A low-energy attractive force between hydrogen and another element. It plays a major role in determining the properties of water, proteins, and other compounds.
Inorganic salts of hydrofluoric acid, HF, in which the fluorine atom is in the -1 oxidation state. (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed) Sodium and stannous salts are commonly used in dentifrices.
Injuries to DNA that introduce deviations from its normal, intact structure and which may, if left unrepaired, result in a MUTATION or a block of DNA REPLICATION. These deviations may be caused by physical or chemical agents and occur by natural or unnatural, introduced circumstances. They include the introduction of illegitimate bases during replication or by deamination or other modification of bases; the loss of a base from the DNA backbone leaving an abasic site; single-strand breaks; double strand breaks; and intrastrand (PYRIMIDINE DIMERS) or interstrand crosslinking. Damage can often be repaired (DNA REPAIR). If the damage is extensive, it can induce APOPTOSIS.
Inosine 5'-Monophosphate. A purine nucleotide which has hypoxanthine as the base and one phosphate group esterified to the sugar moiety.
Liquid chromatographic techniques which feature high inlet pressures, high sensitivity, and high speed.
A DNA repair enzyme that is an N-glycosyl hydrolase with specificity for DNA-containing ring-opened N(7)-methylguanine residues.
The relative amounts of the PURINES and PYRIMIDINES in a nucleic acid.
Compounds and molecular complexes that consist of very large numbers of atoms and are generally over 500 kDa in size. In biological systems macromolecular substances usually can be visualized using ELECTRON MICROSCOPY and are distinguished from ORGANELLES by the lack of a membrane structure.
Disruption of the secondary structure of nucleic acids by heat, extreme pH or chemical treatment. Double strand DNA is "melted" by dissociation of the non-covalent hydrogen bonds and hydrophobic interactions. Denatured DNA appears to be a single-stranded flexible structure. The effects of denaturation on RNA are similar though less pronounced and largely reversible.
Purine bases found in body tissues and fluids and in some plants.
GTP-BINDING PROTEINS that contain three non-identical subunits. They are found associated with members of the seven transmembrane domain superfamily of G-PROTEIN-COUPLED RECEPTORS. Upon activation the GTP-BINDING PROTEIN ALPHA SUBUNIT of the complex dissociates leaving a dimer of a GTP-BINDING PROTEIN BETA SUBUNIT bound to a GTP-BINDING PROTEIN GAMMA SUBUNIT.
A fungal metabolite which is a macrocyclic lactone exhibiting a wide range of antibiotic activity.
A family of DNA repair enzymes that recognize damaged nucleotide bases and remove them by hydrolyzing the N-glycosidic bond that attaches them to the sugar backbone of the DNA molecule. The process called BASE EXCISION REPAIR can be completed by a DNA-(APURINIC OR APYRIMIDINIC SITE) LYASE which excises the remaining RIBOSE sugar from the DNA.
A class of monomeric, low molecular weight (20-25 kDa) GTP-binding proteins that regulate a variety of intracellular processes. The GTP bound form of the protein is active and limited by its inherent GTPase activity, which is controlled by an array of GTPase activators, GDP dissociation inhibitors, and guanine nucleotide exchange factors. This enzyme was formerly listed as EC 3.6.1.47
CELL LINES derived from the CV-1 cell line by transformation with a replication origin defective mutant of SV40 VIRUS, which codes for wild type large T antigen (ANTIGENS, POLYOMAVIRUS TRANSFORMING). They are used for transfection and cloning. (The CV-1 cell line was derived from the kidney of an adult male African green monkey (CERCOPITHECUS AETHIOPS).)
An adenine nucleotide containing one phosphate group which is esterified to both the 3'- and 5'-positions of the sugar moiety. It is a second messenger and a key intracellular regulator, functioning as a mediator of activity for a number of hormones, including epinephrine, glucagon, and ACTH.
The uptake of naked or purified DNA by CELLS, usually meaning the process as it occurs in eukaryotic cells. It is analogous to bacterial transformation (TRANSFORMATION, BACTERIAL) and both are routinely employed in GENE TRANSFER TECHNIQUES.
A ubiquitously expressed family of heterotrimeric GTP-binding protein alpha subunits that signal through interactions with a variety of second messengers as GTPASE-ACTIVATING PROTEINS; GUANINE NUCLEOTIDE EXCHANGE FACTORS; and HEAT SHOCK PROTEINS. The G12-G13 part of the name is also spelled G12/G13.
Chemical agents that increase the rate of genetic mutation by interfering with the function of nucleic acids. A clastogen is a specific mutagen that causes breaks in chromosomes.
Process of generating a genetic MUTATION. It may occur spontaneously or be induced by MUTAGENS.
Cells propagated in vitro in special media conducive to their growth. Cultured cells are used to study developmental, morphologic, metabolic, physiologic, and genetic processes, among others.
The introduction of a phosphoryl group into a compound through the formation of an ester bond between the compound and a phosphorus moiety.
The location of the atoms, groups or ions relative to one another in a molecule, as well as the number, type and location of covalent bonds.
Recombinant proteins produced by the GENETIC TRANSLATION of fused genes formed by the combination of NUCLEIC ACID REGULATORY SEQUENCES of one or more genes with the protein coding sequences of one or more genes.
The process of cleaving a chemical compound by the addition of a molecule of water.
A genetically related subfamily of RAB GTP-BINDING PROTEINS involved in vesicle transport between the ENDOPLASMIC RETICULUM and the GOLGI APPARATUS and through early Golgi compartments. This enzyme was formerly listed as EC 3.6.1.47.
PROTEINS that specifically activate the GTP-phosphohydrolase activity of RAS PROTEINS.
A subclass of phospholipases that hydrolyze the phosphoester bond found in the third position of GLYCEROPHOSPHOLIPIDS. Although the singular term phospholipase C specifically refers to an enzyme that catalyzes the hydrolysis of PHOSPHATIDYLCHOLINE (EC 3.1.4.3), it is commonly used in the literature to refer to broad variety of enzymes that specifically catalyze the hydrolysis of PHOSPHATIDYLINOSITOLS.
The GTPase-containing subunits of heterotrimeric GTP-binding proteins. When dissociated from the heterotrimeric complex these subunits interact with a variety of second messenger systems. Hydrolysis of GTP by the inherent GTPase activity of the subunit causes it to revert to its inactive (heterotrimeric) form. The GTP-Binding protein alpha subunits are grouped into families according to the type of action they have on second messenger systems.
A genetically related subfamily of RAB GTP-BINDING PROTEINS involved in transport from the cell membrane to early endosomes. This enzyme was formerly listed as EC 3.6.1.47.
Compounds based on 2-amino-4-hydroxypteridine.
A species of the genus SACCHAROMYCES, family Saccharomycetaceae, order Saccharomycetales, known as "baker's" or "brewer's" yeast. The dried form is used as a dietary supplement.
The study of crystal structure using X-RAY DIFFRACTION techniques. (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)
Nucleotides in which the purine or pyrimidine base is combined with ribose. (Dorland, 28th ed)
One of two major pharmacologically defined classes of adrenergic receptors. The beta adrenergic receptors play an important role in regulating CARDIAC MUSCLE contraction, SMOOTH MUSCLE relaxation, and GLYCOGENOLYSIS.
The reconstruction of a continuous two-stranded DNA molecule without mismatch from a molecule which contained damaged regions. The major repair mechanisms are excision repair, in which defective regions in one strand are excised and resynthesized using the complementary base pairing information in the intact strand; photoreactivation repair, in which the lethal and mutagenic effects of ultraviolet light are eliminated; and post-replication repair, in which the primary lesions are not repaired, but the gaps in one daughter duplex are filled in by incorporation of portions of the other (undamaged) daughter duplex. Excision repair and post-replication repair are sometimes referred to as "dark repair" because they do not require light.
The sum of the weight of all the atoms in a molecule.
A broad category of carrier proteins that play a role in SIGNAL TRANSDUCTION. They generally contain several modular domains, each of which having its own binding activity, and act by forming complexes with other intracellular-signaling molecules. Signal-transducing adaptor proteins lack enzyme activity, however their activity can be modulated by other signal-transducing enzymes
The interaction of two or more substrates or ligands with the same binding site. The displacement of one by the other is used in quantitative and selective affinity measurements.
Derivatives of phosphatidic acids in which the phosphoric acid is bound in ester linkage to the hexahydroxy alcohol, myo-inositol. Complete hydrolysis yields 1 mole of glycerol, phosphoric acid, myo-inositol, and 2 moles of fatty acids.
Potent activator of the adenylate cyclase system and the biosynthesis of cyclic AMP. From the plant COLEUS FORSKOHLII. Has antihypertensive, positive inotropic, platelet aggregation inhibitory, and smooth muscle relaxant activities; also lowers intraocular pressure and promotes release of hormones from the pituitary gland.
A family of heterotrimeric GTP-binding protein alpha subunits that were originally identified by their ability to inhibit ADENYLYL CYCLASES. Members of this family can couple to beta and gamma G-protein subunits that activate POTASSIUM CHANNELS. The Gi-Go part of the name is also spelled Gi/Go.
Reagents with two reactive groups, usually at opposite ends of the molecule, that are capable of reacting with and thereby forming bridges between side chains of amino acids in proteins; the locations of naturally reactive areas within proteins can thereby be identified; may also be used for other macromolecules, like glycoproteins, nucleic acids, or other.
Phosphoric acid esters of inositol. They include mono- and polyphosphoric acid esters, with the exception of inositol hexaphosphate which is PHYTIC ACID.
The characteristic 3-dimensional shape of a protein, including the secondary, supersecondary (motifs), tertiary (domains) and quaternary structure of the peptide chain. PROTEIN STRUCTURE, QUATERNARY describes the conformation assumed by multimeric proteins (aggregates of more than one polypeptide chain).
Highly reactive chemicals that introduce alkyl radicals into biologically active molecules and thereby prevent their proper functioning. Many are used as antineoplastic agents, but most are very toxic, with carcinogenic, mutagenic, teratogenic, and immunosuppressant actions. They have also been used as components in poison gases.
Genetically engineered MUTAGENESIS at a specific site in the DNA molecule that introduces a base substitution, or an insertion or deletion.
Extrachromosomal, usually CIRCULAR DNA molecules that are self-replicating and transferable from one organism to another. They are found in a variety of bacterial, archaeal, fungal, algal, and plant species. They are used in GENETIC ENGINEERING as CLONING VECTORS.
A protein found in bacteria and eukaryotic mitochondria which delivers aminoacyl-tRNA's to the A site of the ribosome. The aminoacyl-tRNA is first bound to a complex of elongation factor Tu containing a molecule of bound GTP. The resulting complex is then bound to the 70S initiation complex. Simultaneously the GTP is hydrolyzed and a Tu-GDP complex is released from the 70S ribosome. The Tu-GTP complex is regenerated from the Tu-GDP complex by the Ts elongation factor and GTP.
A polynucleotide consisting essentially of chains with a repeating backbone of phosphate and ribose units to which nitrogenous bases are attached. RNA is unique among biological macromolecules in that it can encode genetic information, serve as an abundant structural component of cells, and also possesses catalytic activity. (Rieger et al., Glossary of Genetics: Classical and Molecular, 5th ed)
A purine nucleoside that has hypoxanthine linked by the N9 nitrogen to the C1 carbon of ribose. It is an intermediate in the degradation of purines and purine nucleosides to uric acid and in pathways of purine salvage. It also occurs in the anticodon of certain transfer RNA molecules. (Dorland, 28th ed)
The first continuously cultured human malignant CELL LINE, derived from the cervical carcinoma of Henrietta Lacks. These cells are used for VIRUS CULTIVATION and antitumor drug screening assays.
7,8,8a,9a-Tetrahydrobenzo(10,11)chryseno (3,4-b)oxirene-7,8-diol. A benzopyrene derivative with carcinogenic and mutagenic activity.
Transforming protein encoded by ras oncogenes. Point mutations in the cellular ras gene (c-ras) can also result in a mutant p21 protein that can transform mammalian cells. Oncogene protein p21(ras) has been directly implicated in human neoplasms, perhaps accounting for as much as 15-20% of all human tumors. This enzyme was formerly listed as EC 3.6.1.47.
Organic esters of sulfuric acid.
Eukaryotic initiation factor of protein synthesis. In higher eukaryotes the factor consists of three subunits: alpha, beta, and gamma. As initiation proceeds, eIF-2 forms a ternary complex with Met-tRNAi and GTP.
Products of proto-oncogenes. Normally they do not have oncogenic or transforming properties, but are involved in the regulation or differentiation of cell growth. They often have protein kinase activity.
Cell surface proteins that bind signalling molecules external to the cell with high affinity and convert this extracellular event into one or more intracellular signals that alter the behavior of the target cell (From Alberts, Molecular Biology of the Cell, 2nd ed, pp693-5). Cell surface receptors, unlike enzymes, do not chemically alter their ligands.
Screening techniques first developed in yeast to identify genes encoding interacting proteins. Variations are used to evaluate interplay between proteins and other molecules. Two-hybrid techniques refer to analysis for protein-protein interactions, one-hybrid for DNA-protein interactions, three-hybrid interactions for RNA-protein interactions or ligand-based interactions. Reverse n-hybrid techniques refer to analysis for mutations or other small molecules that dissociate known interactions.
Isopropyl analog of EPINEPHRINE; beta-sympathomimetic that acts on the heart, bronchi, skeletal muscle, alimentary tract, etc. It is used mainly as bronchodilator and heart stimulant.
The key substance in the biosynthesis of histidine, tryptophan, and purine and pyrimidine nucleotides.
Addition of methyl groups. In histo-chemistry methylation is used to esterify carboxyl groups and remove sulfate groups by treating tissue sections with hot methanol in the presence of hydrochloric acid. (From Stedman, 25th ed)
Spectroscopic method of measuring the magnetic moment of elementary particles such as atomic nuclei, protons or electrons. It is employed in clinical applications such as NMR Tomography (MAGNETIC RESONANCE IMAGING).
A purine that is an isomer of ADENINE (6-aminopurine).
The facilitation of a chemical reaction by material (catalyst) that is not consumed by the reaction.
Proteins which are found in membranes including cellular and intracellular membranes. They consist of two types, peripheral and integral proteins. They include most membrane-associated enzymes, antigenic proteins, transport proteins, and drug, hormone, and lectin receptors.
A chemical reaction in which an electron is transferred from one molecule to another. The electron-donating molecule is the reducing agent or reductant; the electron-accepting molecule is the oxidizing agent or oxidant. Reducing and oxidizing agents function as conjugate reductant-oxidant pairs or redox pairs (Lehninger, Principles of Biochemistry, 1982, p471).
Electrophoresis in which a polyacrylamide gel is used as the diffusion medium.
Agents that are capable of inserting themselves between the successive bases in DNA, thus kinking, uncoiling or otherwise deforming it and therefore preventing its proper functioning. They are used in the study of DNA.
A mutation caused by the substitution of one nucleotide for another. This results in the DNA molecule having a change in a single base pair.
High molecular weight polymers containing a mixture of purine and pyrimidine nucleotides chained together by ribose or deoxyribose linkages.
Agents used in the prophylaxis or therapy of VIRUS DISEASES. Some of the ways they may act include preventing viral replication by inhibiting viral DNA polymerase; binding to specific cell-surface receptors and inhibiting viral penetration or uncoating; inhibiting viral protein synthesis; or blocking late stages of virus assembly.
A modified nucleoside which is present in the first position of the anticodon of tRNA-tyrosine, tRNA-histidine, tRNA-asparagine and tRNA-aspartic acid of many organisms. It is believed to play a role in the regulatory function of tRNA. Nucleoside Q can be further modified to nucleoside Q*, which has a mannose or galactose moiety linked to position 4 of its cyclopentenediol moiety.
Substances that increase the risk of NEOPLASMS in humans or animals. Both genotoxic chemicals, which affect DNA directly, and nongenotoxic chemicals, which induce neoplasms by other mechanism, are included.
Theoretical representations that simulate the behavior or activity of biological processes or diseases. For disease models in living animals, DISEASE MODELS, ANIMAL is available. Biological models include the use of mathematical equations, computers, and other electronic equipment.
Nucleosides in which the purine or pyrimidine base is combined with ribose. (Dorland, 28th ed)
DNA-dependent DNA polymerases found in bacteria, animal and plant cells. During the replication process, these enzymes catalyze the addition of deoxyribonucleotide residues to the end of a DNA strand in the presence of DNA as template-primer. They also possess exonuclease activity and therefore function in DNA repair.
The property of objects that determines the direction of heat flow when they are placed in direct thermal contact. The temperature is the energy of microscopic motions (vibrational and translational) of the particles of atoms.
Organic compounds that include a cyclic ether with three ring atoms in their structure. They are commonly used as precursors for POLYMERS such as EPOXY RESINS.
Cell lines whose original growing procedure consisted being transferred (T) every 3 days and plated at 300,000 cells per plate (J Cell Biol 17:299-313, 1963). Lines have been developed using several different strains of mice. Tissues are usually fibroblasts derived from mouse embryos but other types and sources have been developed as well. The 3T3 lines are valuable in vitro host systems for oncogenic virus transformation studies, since 3T3 cells possess a high sensitivity to CONTACT INHIBITION.
Proteins that control the CELL DIVISION CYCLE. This family of proteins includes a wide variety of classes, including CYCLIN-DEPENDENT KINASES, mitogen-activated kinases, CYCLINS, and PHOSPHOPROTEIN PHOSPHATASES as well as their putative substrates such as chromatin-associated proteins, CYTOSKELETAL PROTEINS, and TRANSCRIPTION FACTORS.
A large lobed glandular organ in the abdomen of vertebrates that is responsible for detoxification, metabolism, synthesis and storage of various substances.
An antineoplastic compound which also has antimetabolite action. The drug is used in the therapy of acute leukemia.
6-(Methylthio)-9-beta-D-ribofuranosylpurine. An analog of inosine with a methylthio group replacing the hydroxyl group in the 6-position.
Proteins found in any species of fungus.
A family of heterotrimeric GTP-binding protein alpha subunits that activate ADENYLYL CYCLASES.
Furano-furano-benzopyrans that are produced by ASPERGILLUS from STERIGMATOCYSTIN. They are structurally related to COUMARINS and easily oxidized to an epoxide form to become ALKYLATING AGENTS. Members of the group include AFLATOXIN B1; aflatoxin B2, aflatoxin G1, aflatoxin G2; AFLATOXIN M1; and aflatoxin M2.
The process of moving proteins from one cellular compartment (including extracellular) to another by various sorting and transport mechanisms such as gated transport, protein translocation, and vesicular transport.
A type C phospholipase with specificity towards PHOSPHATIDYLINOSITOLS that contain INOSITOL 1,4,5-TRISPHOSPHATE. Many of the enzymes listed under this classification are involved in intracellular signaling.
A family of serine-threonine kinases that bind to and are activated by MONOMERIC GTP-BINDING PROTEINS such as RAC GTP-BINDING PROTEINS and CDC42 GTP-BINDING PROTEIN. They are intracellular signaling kinases that play a role the regulation of cytoskeletal organization.
Transport proteins that carry specific substances in the blood or across cell membranes.
The arrangement of two or more amino acid or base sequences from an organism or organisms in such a way as to align areas of the sequences sharing common properties. The degree of relatedness or homology between the sequences is predicted computationally or statistically based on weights assigned to the elements aligned between the sequences. This in turn can serve as a potential indicator of the genetic relatedness between the organisms.
Proteins obtained from the species SACCHAROMYCES CEREVISIAE. The function of specific proteins from this organism are the subject of intense scientific interest and have been used to derive basic understanding of the functioning similar proteins in higher eukaryotes.
An ACYCLOVIR analog that is a potent inhibitor of the Herpesvirus family including cytomegalovirus. Ganciclovir is used to treat complications from AIDS-associated cytomegalovirus infections.
Large woodland game BIRDS in the subfamily Meleagridinae, family Phasianidae, order GALLIFORMES. Formerly they were considered a distinct family, Melegrididae.
A monomeric GTP-binding protein involved in nucleocytoplasmic transport of proteins into the nucleus and RNA into the cytoplasm. This enzyme was formerly listed as EC 3.6.1.47.
A basic element found in nearly all organized tissues. It is a member of the alkaline earth family of metals with the atomic symbol Ca, atomic number 20, and atomic weight 40. Calcium is the most abundant mineral in the body and combines with phosphorus to form calcium phosphate in the bones and teeth. It is essential for the normal functioning of nerves and muscles and plays a role in blood coagulation (as factor IV) and in many enzymatic processes.
A subfamily in the family MURIDAE, comprising the hamsters. Four of the more common genera are Cricetus, CRICETULUS; MESOCRICETUS; and PHODOPUS.
The portion of a retinal rod cell situated between the ROD INNER SEGMENT and the RETINAL PIGMENT EPITHELIUM. It contains a stack of photosensitive disk membranes laden with RHODOPSIN.
A protein complex comprised of COATOMER PROTEIN and ADP RIBOSYLATION FACTOR 1. It is involved in transport of vesicles between the ENDOPLASMIC RETICULUM and the GOLGI APPARATUS.

Long-range oxidative damage to DNA: effects of distance and sequence. (1/3529)

INTRODUCTION: Oxidative damage to DNA in vivo can lead to mutations and cancer. DNA damage and repair studies have not yet revealed whether permanent oxidative lesions are generated by charges migrating over long distances. Both photoexcited *Rh(III) and ground-state Ru(III) intercalators were previously shown to oxidize guanine bases from a remote site in oligonucleotide duplexes by DNA-mediated electron transfer. Here we examine much longer charge-transport distances and explore the sensitivity of the reaction to intervening sequences. RESULTS: Oxidative damage was examined in a series of DNA duplexes containing a pendant intercalating photooxidant. These studies revealed a shallow dependence on distance and no dependence on the phasing orientation of the oxidant relative to the site of damage, 5'-GG-3'. The intervening DNA sequence has a significant effect on the yield of guanine oxidation, however. Oxidation through multiple 5'-TA-3' steps is substantially diminished compared to through other base steps. We observed intraduplex guanine oxidation by tethered *Rh(III) and Ru(III) over a distance of 200 A. The distribution of oxidized guanine varied as a function of temperature between 5 and 35 degrees C, with an increase in the proportion of long-range damage (> 100 A) occurring at higher temperatures. CONCLUSIONS: Guanines are oxidized as a result of DNA-mediated charge transport over significant distances (e.g. 200 A). Although long-range charge transfer is dependent on distance, it appears to be modulated by intervening sequence and sequence-dependent dynamics. These discoveries hold important implications with respect to DNA damage in vivo.  (+info)

Regulation of de novo purine biosynthesis in human lymphoblasts. Coordinate control of proximal (rate-determining) steps and the inosinic acid branch point. (2/3529)

Purine nucleotide synthesis de novo has been studied in a permanent tissue culture line of human splenic lymphoblasts with particular attention to coordination of control of the proximal (rate-determining) steps with the distal branch point of the pathway. An assay was used which permits simultaneous determination of the overall rate of labeling of all intracellular purines with sodium [14C]formate, as well as the distribution of isotope into all intracellular guanine- and adenine-containing compounds. The guanine to adenine labeling ratio was used as an index of IMP branch point regulation. It was found that exogenous adenine and guanine produce feedback-controlling effects not only on the first step in the de novo pathway, but also on the IMP branch point. Concentrations of adenine which produce less than 40% inhibition of the overall rate of de novo purine synthesis do so by selectively inhibiting adenine nucleotide synthesis de novo by 50 to 70% while stimulating guanine nucleotide synthesis de novo by up to 20%. A reciprocal effect is seen with exogenous guanine. The adenosine analog 6-methylmercaptopurine ribonucleoside selectivity inhibits adenine nucleotide synthesis via the de novo pathway but not from exogenous hypoxanthine. Thus, the reactions of purine nucleotide interconversion, in particular adenylosuccinate synthetase, may be regulated differently in cells deriving their purine nucleotides solely from de novo synthesis than when deriving them via "salvage" of preformed hypoxanthine.  (+info)

The effect of cotinine or cigarette smoke co-administration on the formation of O6-methylguanine adducts in the lung and liver of A/J mice treated with 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK) (3/3529)

4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK), a tobacco-specific nitrosamine, induces lung adenomas in A/J mice, following a single intraperitoneal (i.p.) injection. However, inhalation of tobacco smoke has not induced or promoted tumors in these mice. NNK-induced lung tumorigenesis is thought to involve O6-methylguanine (O6MeG) formation, leading to GC-->AT transitional mispairing and an activation of the K-ras proto-oncogene in the A/J mouse. NNK can be metabolized by several different cytochromes P450, resulting in a number of metabolites. Formation of the promutagenic DNA adduct O6MeG is believed to require metabolic activation of NNK by cytochrome P450-mediated alpha-hydroxylation of the methylene group adjacent to the N-nitroso nitrogen to yield the unstable intermediate, methanediazohydroxide. Nicotine, cotinine (the major metabolite of nicotine), and aqueous cigarette tar extract (ACTE) have all been shown to effectively inhibit metabolic activation of NNK to its mutagenic form, most likely due to competitive inhibition of the cytochrome P450 enzymes involved in alpha-hydroxylation of NNK. The objective of the current study was to monitor the effects of cotinine and cigarette smoke (CS) on the formation of O6MeG in target tissues of mice during the acute phase of NNK treatment. To test the effect of cotinine, mature female A/J mice received a single intraperitoneal injection of NNK (0, 2.5, 5, 7.5, or 10 mumole/mouse) with cotinine administered at a total dose of 50 mumole/mouse in 3 separate i.p. injections, administered 30 min before, immediately after, and 30 min after NNK treatment. To test the effect of whole smoke exposure on NNK-related O6MeG formation, mice were exposed to smoke generated from Kentucky 1R4F reference cigarettes at 0, 0.4, 0.6, or 0.8 mg wet total particulate matter/liter (WTPM/L) for 2 h, with a single i.p. injection of NNK (0, 3.75, or 7.5 mumole/mouse) midway through the exposure. Cigarette smoke alone failed to yield detectable levels of O6MeG. The number of O6MeG adducts following i.p. injection of NNK was significantly (p < 0.05) reduced in both lung and liver by cotinine and by cigarette smoke exposure. Our results demonstrate that NNK-induced O6MeG DNA adducts in A/J mice are significantly reduced when NNK is administered together with either cotinine, the major metabolite of nicotine, or the parental complex mixture, cigarette smoke.  (+info)

Comparative study of the anti-human cytomegalovirus activities and toxicities of a tetrahydrofuran phosphonate analogue of guanosine and cidofovir. (4/3529)

Cidofovir is the first nucleoside monophosphate analogue currently being used for the treatment of human cytomegalovirus (HCMV) retinitis in individuals with AIDS. Unfortunately, the period of therapy with the use of this compound may be limited due to the possible emergence of serious irreversible nephrotoxic effects. New drugs with improved toxicity profiles are needed. The goal of this study was to investigate the anticytomegaloviral properties and drug-induced toxicity of a novel phosphonate analogue, namely, (-)-2-(R)-dihydroxyphosphinoyl-5-(S)-(guanin-9'-yl-methyl) tetrahydrofuran (compound 1), in comparison with those of cidofovir. The inhibitory activities of both compounds on HCMV propagation in vitro were similar against the AD 169 and Towne strains, with 50% inhibitory concentrations ranging from 0.02 to 0.17 microgram/ml for cidofovir and < 0.05 to 0.09 microgram/ml for compound 1. A clinical HCMV isolate that was resistant to ganciclovir and that had a known mutation within the UL54 DNA polymerase gene and a cidofovir-resistant laboratory strain derived from strain AD 169 remained sensitive to compound 1, whereas their susceptibilities to ganciclovir and cidofovir were reduced by 33- and 10-fold, respectively. Both compound 1 and cidofovir exhibited equal potencies in an experimentally induced murine cytomegalovirus (MCMV) infection in mice, with a prevention or prolongation of mean day to death at dosages of 1.0, 3.2, and 10.0 mg/kg of body weight/day. In cytotoxicity experiments, compound 1 was found to be generally more toxic than cidofovir in cell lines Hs68, HFF, and 3T3-L1 (which are permissive for HCMV or MCMV replication) but less toxic than cidofovir in MRC-5 cells (which are permissive for HCMV replication). Drug-induced toxic side effects were noticed for both compounds in rats and guinea pigs in a 5-day repeated-dose study. In guinea pigs, a greater weight loss was noticed with cidofovir than with compound 1 at dosages of 3.0 and 10.0 mg/kg/day. An opposite effect was detected in rats, which were treated with the compounds at relatively high dosages (up to 100 mg/kg/day). Compound 1 and cidofovir were nephrotoxic in both rats and guinea pigs, with the epithelium lining the proximal convoluted tubules in the renal cortex being the primary target site. The incidence and the severity of the lesions were found to be dose dependent. The lesions observed were characterized by cytoplasm degeneration and nuclear modifications such as karyomegaly, the presence of pseudoinclusions, apoptosis, and degenerative changes. In the guinea pig model, a greater incidence and severity of lesions were observed for cidofovir than for compound 1 (P < 0.001) with a drug regimen of 10 mg/kg/day.  (+info)

Mismatch repair and differential sensitivity of mouse and human cells to methylating agents. (5/3529)

The long-patch mismatch repair pathway contributes to the cytotoxic effect of methylating agents and loss of this pathway confers tolerance to DNA methylation damage. Two methylation-tolerant mouse cell lines were identified and were shown to be defective in the MSH2 protein by in vitro mismatch repair assay. A normal copy of the human MSH2 gene, introduced by transfer of human chromosome 2, reversed the methylation tolerance. These mismatch repair defective mouse cells together with a fibroblast cell line derived from an MSH2-/- mouse, were all as resistant to N-methyl-N-nitrosourea as repair-defective human cells. Although long-patch mismatch repair-defective human cells were 50- to 100-fold more resistant to methylating agents than repair-proficient cells, loss of the same pathway from mouse cells conferred only a 3-fold increase. This discrepancy was accounted for by the intrinsic N-methyl-N-nitrosourea resistance of normal or transformed mouse cells compared with human cells. The >20-fold differential resistance between mouse and human cells could not be explained by the levels of either DNA methylation damage or the repair enzyme O6-methylguanine-DNA methyltransferase. The resistance of mouse cells to N-methyl-N-nitrosourea was selective and no cross-resistance to unrelated DNA damaging agents was observed. Pathways of apoptosis were apparently intact and functional after exposure to either N-methyl-N-nitrosourea or ultraviolet light. Extracts of mouse cells were found to perform 2-fold less long-patch mismatch repair. The reduced level of mismatch repair may contribute to their lack of sensitivity to DNA methylation damage.  (+info)

The major, N2-dG adduct of (+)-anti-B[a]PDE induces G-->A mutations in a 5'-AGA-3' sequence context. (6/3529)

Previously, in a random mutagenesis study, the (+)-anti diol epoxide of benzo[a]pyrene [(+)-anti-B[a]PDE] was shown to induce a complex mutational spectrum in the supF gene of an Escherichia coli plasmid, which included insertions, deletions and base substitution mutations, notably a significant fraction of GC-->TA, GC-->AT and GC-->CG mutations. At some sites, a single type of mutation dominated and to understand individual mutagenic pathways these sites were chosen for study by site-specific means to determine whether the major adduct, [+ta]-B[a]P-N2-dG, was responsible. [+ta]-B[a]P-N2-dG was shown to induce approximately 95% G-->T mutations in a 5'-TGC-3' sequence context and approximately 80% G-->A mutations in a 5'-CGT-3' sequence context. (+)-anti-B[a]PDE induced principally GC-->CG mutations in the G133 sequence context (5'-AGA-3') in studies using both SOS-uninduced or SOS-induced E. coli. Herein, [+ta]-B[a]P-N2-dG is shown to induce principally G-->A mutations (>90%) either without or with SOS induction in a closely related 5'-AGA-3' sequence context (identical over 7 bp). This is the first time that there has been a discrepancy between the mutagenic specificity of (+)-anti-B[a]PDE versus [+ta]-B[a]P-N2-dG. Eight explanations for this discordance are considered. Four are ruled out; e.g. the second most prevalent adduct [+ca]-B[a]P-N2-dG also induces a preponderance of G-->A mutations (>90%), so it also is not responsible for (+)-anti-B[a]PDE-induced G133-->C mutations. The four explanations not ruled out are discussed and include that another minor adduct might be responsible and that the 5'-AGA-3' sequence context differed slightly in the studies with [+ta]-B[a]P-N2-dG versus (+)-anti-B[a]PDE. In spite of the discordance, [+ta]-B[a]P-N2-dG induces G-->A mutations in the context studied herein and this result has proven useful in generating a hypothesis for what conformations of [+ta]-B[a]P-N2-dG are responsible for G-->T versus G-->A mutations.  (+info)

In vitro reactions of butadiene monoxide with single- and double-stranded DNA: characterization and quantitation of several purine and pyrimidine adducts. (7/3529)

We have previously shown that butadiene monoxide (BM), the primary metabolite of 1,3-butadiene, reacted with nucleosides to form alkylation products that exhibited different rates of formation and different stabilities under in vitro physiological conditions. In the present study, BM was reacted with single-stranded (ss) and double-stranded (ds) calf thymus DNA and the alkylation products were characterized after enzymatic hydrolysis of the DNA. The primary products were regioisomeric N-7-guanine adducts. N-3-(2-hydroxy-3-buten-1-yl)adenine and N-3-(1-hydroxy-3-buten-2-yl)adenine, which were depurinated from the DNA more rapidly than the N-7-guanine adducts, were also formed. In addition, N6-(2-hydroxy-3-buten-1-yl)deoxyadenosine and N6-(1-hydroxy-3-buten-2-yl)deoxyadenosine were detected and evidence was obtained that these adducts were formed by Dimroth rearrangement of the corresponding N-1-deoxyadenosine adducts, not while in the DNA, but following the release of the N-1-alkylated nucleosides by enzymatic hydrolysis. N-3-(2-hydroxy-3-buten-1-yl)deoxyuridine adducts, which were apparently formed subsequent to deamination reactions of the corresponding deoxycytidine adducts, were also detected and were stable in the DNA. Adduct formation was linearly dependent upon BM concentration (10-1000 mM), with adduct ratios being similar at the various BM concentrations. At a high BM concentration (750 mM), the adducts were formed in a linear fashion for up to 8 h in both ssDNA and dsDNA. However, the rates of formation of the N-3-deoxyuridine and N6-deoxyadenosine adducts increased 10- to 20-fold in ssDNA versus dsDNA, whereas the N-7-guanine adducts increased only slightly, presumably due to differences in hydrogen bonding in ssDNA versus dsDNA. These results may contribute to a better understanding of the molecular mechanisms of mutagenesis and carcinogenesis of both BM and its parent compound, 1,3-butadiene.  (+info)

Identification of a C/G polymorphism in the promoter region of the BRCA1 gene and its use as a marker for rapid detection of promoter deletions. (8/3529)

Reduced expression of BRCA1 has been implicated in sporadic breast cancer, although the mechanisms underlying this phenomenon remain unclear. To determine whether regulatory mutations could account for the reduced expression, we screened the promoter region by sequencing in 20 patients with sporadic disease. No mutations were detected; however, a new polymorphism consisting of a C-to-G base change within the beta-promoter was identified, with the frequency of the G allele being 0.34. Close to complete linkage disequilibrium was found between this marker and the Pro871 Leu polymorphism, situated in exon 11, which has previously been shown not to be associated with breast or ovarian cancer. This indicates that the C/G polymorphism is also unlikely to play a role in either disease. However, the strength of linkage disequilibrium between these markers permitted their use for rapid screening for genomic deletions within BRCA1. A series of 214 cases with familial breast cancer were analysed using this approach; 88/214 were heterozygous for the promoter polymorphism, thereby excluding a deletion in this region. Among the remaining patients, one hemizygous case reflecting a promoter deletion was successfully identified. Therefore, this study indicates that deletions within the beta-promoter region of BRCA1 are an uncommon event in familial breast cancer. Furthermore, it suggests that mutations within the BRCA1 promoter are unlikely to account for the reported decreased expression of BRCA1 in sporadic disease.  (+info)

OBJECTIVES:. I. To determine the dose limiting toxicity (DLT) and maximally tolerated dose (MTD) of PTK/ZK and pemetrexed disodium when given in combination.. II. To describe the toxicities associated with the combination of PTK/ZK with pemetrexed disodium.. III. To evaluate the pharmacokinetic interaction of combination of PTK/ZK with pemetrexed disodium at the MTD (Group II).. IV. To evaluate the intracellular content of pemetrexed disodium polyglutamates as a measure of activity of pemetrexed disodium transport and activation enzymes in the MTD expansion cohort (Group II).. V. To evaluate polymorphisms and gene expression of pemetrexed disodium target genes, and genes encoding enzymes involved in the transport, activation, and inactivation of pemetrexed disodium, and correlate haplotype-tagged SNPs or gene expression levels with intracellular levels of pemetrexed disodium polyglutamates, toxicity and/or efficacy or pemetrexed disodium in Group II.. VI. To evaluate pharmacogenetic, metabolic ...
RATIONALE: Drugs used in chemotherapy, such as gemcitabine hydrochloride and carboplatin, work in different ways to stop the growth of tumor cells, either by killing the cells or by stopping them from dividing. Pemetrexed disodium and celecoxib may stop the growth of tumor cells by blocking some of the enzymes needed for cell growth. It is not yet known whether giving gemcitabine hydrochloride or pemetrexed disodium together with carboplatin is more effective with or without celecoxib in treating non-small cell lung cancer.. PURPOSE: This randomized phase III trial is studying gemcitabine hydrochloride, pemetrexed disodium, and carboplatin to compare how well they work when given together with celecoxib or a placebo in treating patients with advanced non-small cell lung cancer. ...
TY - JOUR. T1 - A phase III trial of pemetrexed plus gemcitabine versus gemcitabine in patients with unresectable or metastatic pancreatic cancer. AU - Oettle, Helmut. AU - Richards, D.. AU - Ramanathan, R. K.. AU - van Laethem, J. L.. AU - Peeters, M.. AU - Fuchs, M.. AU - Zimmermann, A.. AU - John, W.. AU - Von Hoff, D.. AU - Arning, M.. AU - Kindler, H. L.. N1 - Funding Information: The authors wish to acknowledge the patients, nurses, study coordinators and investigators for their active participation in the study. This trial was supported by Eli Lilly and Company, Indianapolis, IN, USA. This study was presented in part at the 40th Annual Meeting of the American Society of Clinical Oncology, New Orleans, LA, 5-8 June 2004, and the World Conference on Gastrointestinal Cancer, Barcelona, Spain, 16-19 June 2004.. PY - 2005/10. Y1 - 2005/10. N2 - Background: This randomized phase III study compared the overall survival (OS) of pemetrexed plus gemcitabine (PG) versus standard gemcitabine (G) in ...
Guanine is the most readily oxidized of the four DNA bases, and guanine oxidation products cause G:C-T:A and G:C-C:G transversions through DNA replication. 8-Oxo-7,8-dihydroguanine (8-oxoG) causes G:C-T:A transversions but not G:C-C:G transversions, and is more readily oxidized than guanine. This review covers four major findings. (i) 2,2,4-Triamino-5(2H)-oxazolone (Oz) is produced from guanine and 8-oxoG under various oxidative conditions. Guanine is incorporated opposite Oz by DNA polymerases, except REV1. (ii) Several enzymes exhibit incision activity towards Oz. (iii) Since the redox potential of GG is lower than that of G, contiguous GG sequences are more readily oxidized by a one-electron oxidant than a single guanine, and OzOz is produced from GG in double-stranded DNA. Unlike most DNA polymerases, DNA polymerase ζ efficiently extends the primer up to full-length across OzOz. (iv) In quadruplex DNA, 3′-guanine is mainly damaged by one-electron oxidation in quadruplex DNA, and this damage
So my dad has NSCLC type adenocarcinoma. He has had 5 rounds of chemo with Carboplatin and Alimta. I just read that ALIMTA is a chemotherapy drug used to treat certain kinds of non-small cell lung cancer (NSCLC) called advanced nonsquamous NSCLC. This is from the Alimta website (alimta.com). Now I am confused as to why my dad is on Alimta if its for nonsquamous type. Anyone else with adenocarcinoma been on Alimta? My dad is going to begin maintenance therapy with avastin but I was wondering if I should ask the doctor if there is other types of chemo we should try before going to maintenance therapy? Any thoughts?. Thanks in advance! ...
Top Quality 99% Entecavir CAS 142217-69-4 Entecavir Product Name:Entecavir Entecavir CAS NO.:142217-69-4 Entecavir Molecular Formula:C12H15N5O3 Entecavir Molecular Weight:277.28 Entecavir Appearance:White to off-white powder Entecavir,abbreviated...
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Data presented today at the 42nd American Society of Clinical Oncology (ASCO) annual meeting in Atlanta, Ga., affirms that ALIMTA® (pemetrexed), manufactured and marketed by Eli Lilly and Company, offers patients with advanced non-small cell lung cancer (NSCLC) similar overall survival as docetaxel (Taxotere®).. The survival data were part of a large (n=571), randomized Phase III study to evaluate the efficacy and safety profile of Alimta as second-line therapy in NSCLC. First reported in 2003(i), the study found that patients in the Alimta arm achieved 8.3 months of median survival, whereas those in the docetaxel arm obtained 7.9 months. This updated analysis of data tracked patients from the same study nearly two years beyond the conclusion of the original study and found similar results. The updated data showed that patients who received Alimta experienced 8.3 months of median survival compared to 8.0 months for those in the docetaxel arm. The data mirror previously reported results and ...
This phase I pilot trial studies how well atezolizumab, pemetrexed disodium, cisplatin, and surgery with or without radiation therapy in treating patients
Current peaks related to guanine oxidation of the probe-modified-PGE after (a) and before hybridization with DENV-3 (b); in the presence of non-complementary se
Alimta infusion contains the active ingredient pemetrexed disodium, which is a type of chemotherapy medicine for cancer called a cytotoxic antimetabolite.
Learn how ALIMTA may help treat advanced nonsquamous non-small cell lung cancer. Find information about ALIMTA and platinum chemotherapy (carboplatin or cisplatin) in combination with KEYTRUDA® (pembrolizumab).
TY - JOUR. T1 - Toxicity of intracranial and intraperitoneal O6-benzyl guanine in combination with BCNU delivered locally in a mouse model. AU - Guarnieri, Michael. AU - Biser-Rohrbaugh, Ann. AU - Tyler, Betty Mae. AU - Gabikian, Patrik. AU - Bunton, Tracie E.. AU - Ze Wu, Qing. AU - Weingart, Jon David. AU - Solomon, Benjamin. PY - 2002. Y1 - 2002. N2 - Purpose: The DNA-repair protein, O6-alkylguanine-DNA alkyl transferase, may account for resistance of CNS tumors to DNA-alkylating drugs, such as bis-(2-chloroethyl)-1-nitrosourea (BCNU). The therapeutic effects of BCNU can be potentiated by inhibiting the repair protein with an alkylated guanine analog, O6-benzyl guanine (O6BG). To investigate potential toxicity of this inhibition, we examined the effects of O6BG in mice treated with intracranial (i.c.) BCNU given via a biodegradable polymer. Methods: Mice were treated with escalating doses of BCNU chronically delivered i.c., and with chronically delivered O6BG. The O6BG was delivered via a ...
Condition: Malignant Mesothelioma. Estimated Enrollment: 153. Gender: All. Min Age: 18 Years. Age Group: Adult, Older Adult. Current Status: Completed. Study Results: No Results Available. Outcome Measures: Complete macroscopic resection (part 1), Loco-regional relapse-free survival (part 2), Response to neoadjuvant therapy (part 1), Adverse drug reaction to neoadjuvant therapy (part 1). Interventions: Cisplatin, Pemetrexed. Phase: Study Type: Interventional. Study Design: Allocation: Randomized, Intervention Model: Parallel Assignment, Masking: None (Open Label),Primary Purpose: Treatment. Primary Completion Date: March 26, 2014. Completion Date: January 23, 2018. Last Posted Date: May 15, 2019. Location: Universitaetsklinikum Freiburg, Freiburg, Germany. Website Link: https://ClinicalTrials.gov/show/NCT00334594. ...
8-Nitroguanosine is a nitrated base of DNA and RNA. It is formed by peroxynitrite, which is generated from nitric oxide and superoxide anion radical. It is known that a large amount of nitric oxide molecules and superoxide anion, generated by inflammation, causes nitration of guanosine. Since chemically modified nucleotides cause mutation during DNA replication, 8-nitroguanosine is thought to be one of the markers of DNA damage related to mutation and cancer. Because of its very high specificity, monoclonal antibody NO2G52 recognizes 8-nitroguanine and 8-nitroguanosine, but it does not cross-react with normal nucleotide bases, 8-hydroxyguanine, 8-hydroxydeoxyguanosine, 3-nitrotyrosine, xanthine, or 2-nitroimidazole (Fig. 1). The specificity of NO2G52 was determined by a competitive ELISA using an 8-nitroguanosine-BSA-coated plate. As shown in the figures below, NO2G52 has very high affinity for 8-nitroguanine and 8-nitroguanosine, and it slightly cross-reacts with 8-bromoguanosine, ...
The structure and energetics of the base pairing and proton transfer in the Watson-Crick type of guanine-cytosine base pair are studied by the HF/MINI-1 method within the full gradient optimization and self-consistent reaction field techniques. Two minima and the transition state on the connecting minimum energy path were located on the potential energy surface (PES) of this complex. The minima involved the canonical amino-keto base pair (GC) and the 4-iminocytosine-6-hydroxyguanine base pair (G*C*), which the latter being formed from GC by a simultaneous transfer of two protons in neighbouring hydrogen bonds. A polar environment was found to stabilize the canonical structure by 1·3 kcal mol-1 with respect to the rare tautomer G*C*. The GC pair represents the global minimum on the HF/MINI-1 PES in both gas phase and polar environment. The polar environment was also found to decrease the interaction enthalpy of the GC base pair and to influence significantly the geometry of the hydrogen bonds. The
In this study, patients will receive either pemetrexed plus irinotecan or 5-fluorouracil (5-FU), leucovorin, and irinotecan.The purposes of this
We have prepared four complexes of the type [Re(guanine)(2)(X)(CO)(3)] (guanine = 9-methylguanine or 7-methylguanine, X = H(2)O or Br) in order to understand the factors determining the orientation of coordinated purine ligands around the [Re(CO)(3)](+) core. The 9-methylguanine ligand (9-MeG) was chosen as the simplest N(9) derivatized guanine, and 7-methylguanine (7-MeG) was chosen because metal binding to N(9) does not impose steric hindrance. Two types of structures have been elucidated by X-ray crystallography, an HH (head-to-head) and HT (head-to-tail) conformer for each of the guanines. All complexes crystallize in monoclinic space groups: [Re(9-MeG)(2)(H(2)O)(CO)(3)]ClO(4) (2) in P2(1)/n with a = 12.3307(10) A, b = 16.2620(14) A, c = 13.7171(11) A, and beta = 105.525(9) degrees, V = 2650.2(4) A(3), with the two bases in HT orientation and its conformer [Re(9-MeG)(2)(H(2)O)(CO)(3)]Br (3) in P2(1)/n with a = 15.626(13) A, b = 9.5269(5) A, c = 15.4078(13) A, and beta = 76.951(1) degrees, V = 2234.5
This trial assessed the efficacy and tolerability of pemetrexed [Alimta, LY231514, NSC 698037] + cisplatin [NSC 119875] in patients with advanced, persistent,
Among these four types of SNPs, C ↔ T/A ↔ G, A ↔ C/G ↔ T, A ↔ T, and C ↔ G, the neighborhood patterns of nucleotide distributions were, however, quite different from each other (Figure 2). For example, at the −1 site, the trend of nucleotide dynamics was A , T , C , G for the combined C ↔ T/A ↔ G transitions (Figure 2, A and B), T , A , G , C for the combined A ↔ C/G ↔ T transversions (Figure 2, C and D), T , A , C , G for the A ↔ T transversions (Figure 2E), and A , T , G , C for the C ↔ G transversions (Figure 2F), respectively. However, at the +1 site, the trend was G , A , T , C for the combined C ↔ T/A ↔ G transitions (Figure 2, A and B), T , A , G , C for the combined A ↔ C/G ↔ T transversions (Figure 2, C and D), A , T , G , C for the A ↔ T transversions (Figure 2E), and T , A , C , G for the C ↔ G transversions (Figure 2F), respectively.. For the C ↔ T/A ↔ G transitions (Figure 2, A and B), nucleotide A had a high average frequency of 0.3548 ...
Assessment of the change in tumour burden is an important feature of the clinical evaluation of cancer therapeutics: both tumour shrinkage (objective response) and disease progression are useful endpoints in clinical trials. Since RECIST was published in 2000, many investigators, cooperative groups, industry and government authorities have adopted these criteria in the assessment of treatment outcomes. However, a number of questions and issues have arisen which have led to the development of a revised RECIST guideline (version 1.1). Evidence for changes, summarised in separate papers in this special issue, has come from assessment of a large data warehouse (,6500 patients), simulation studies and literature reviews. HIGHLIGHTS OF REVISED RECIST 1.1: Major changes include: Number of lesions to be assessed: based on evidence from numerous trial databases merged into a data warehouse for analysis purposes, the number of lesions required to assess tumour burden for response determination has been ...
Pemetrexed is a cancer medication that interferes with the growth and spread of cancer cells in the body. Pemetrexed is used to treat non-small cell lung cancer after other cancer medications have been tried without successful treatment. Pemetrexed is also used with another medication called cisplatin to treat...
I am a 45 year old female who has been diagnosed with recurrent Stage 3 sarcoma and stage 4 NSCLC. I am now being treated with my third chemo cocktail of Alimta. My first treatment was Gemzar, Taxoter and Neulasta. After a severe reaction to the Gemzar my chemo was changed to Carboplatin, Taxoter an Neulasta. After 4 treatments with the Carboplatin/Taxoter my treatment has been changed to ALIMTA. I am 7 days into my first treatment of 4. My oncologist says it is well tolerated by most patients ...
This trial will assess the efficacy and tolerability of gemcitabine and pemetrexed in combination followed by pemetrexed and concurrent upper abdominal
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Hi All. Its been some time since my last post. Would like to provide some update and get some insight on proper next step.. My mother had finished 4 cycles of carbo + alimta with minimal side effects. Her PET scan afterwards shown improvement in the lung and bone mets, and also her CEI has dropped from over 4000 to around 600. Symptom-wise she had also improved greatly that her cough had stopped completely. The doctors at our government sector followed their standard procedure to stop the carbo and remain alimta as maintenance therapy This is where things go the other way round. Her coughing resumed before the second alimta maintenance treatment and CEI had rose to over 700. Situation did not improve after the 3rd alimta only dose and a PET scan was arranged and it turns out the main tumor and also the bone/adrenal gland mets had all worsen. Doctor suggested alimta is of no use any more and suggested to start keytruda at 2mg/KG/3weeks as a next step (without PDL1 testing).. We consulted our ...
Alimta WP Pemetrexed (brand name Alimta) is a chemotherapy drug manufactured and marketed by Eli Lilly and Company. Its indications are the (...)
The first direct comparison of treating nonsquamous lung cancer with either pemetrexed or docetaxel in addition to cisplatin has shown that the two combinations achieve similar progression-free survival.
The aim of this study is to explore the Clinical Value of Sequential Gefitinib With Pemetrexed/Platinum compare with Pemetrexed/Platinum for Advanced NS
A guanine radical cation (G+.) was site-selectively generated in double-stranded DNA and the hole transport from G+. to a GGG unit in G+.(TTG)NGG sites (N=1-4) was analyzed. The overall rate of the charge tra
Infection and inflammation account for approximately 25% of cancer-causing factors. Inflammation-related cancers are characterized by mutagenic DNA lesions, such as 8-oxo-7,8-dihydro-2-deoxyguanosine (8-oxodG) and 8-nitroguanine.
1PYJ: Solution structure of an O6-[4-oxo-4-(3-pyridyl)butyl]guanine adduct in an 11 mer DNA duplex: evidence for formation of a base triplex.
The transcribed strand of S. cattleya can be inferred to have an average guanine content of 37.85%, since the message strand has a cytosine content of 37.85%. In B. burgdorferi, the transcribed-strand guanine has dropped to 12.17%. The difference between the two is 25.68%. On the message strand, adenine content goes from 13.59% for S. cattleya to 38.71% for B. burgdorferi, a difference of 25.12%. The implication is that if organisms evolve along the general path of the regression line in the above graph, all of the increase in message-strand adenine content can be accounted for by the loss in transcribed-strand guanine content. (The loss of guanine, in this example, was 25.68%, which is comparable to the increase of adenine, 25.12%, differing by only two parts per hundred.) Other organisms show a similar pattern of the change in transcribed-strand guanine equaling the change in message-strand adenine ...
Hi Friends: My Moms chest CT shows stability, and maybe even a little shrinkage in one of the nodules in her left lung. So, we are now done with the carbo/alimta combo and have moved on to single agent maintenance Alimta. She had her first dose of maintenance Alimta today. My Mom is battling a lot of fatigue at the moment. . .so her doc is going to see if she can get Provigil
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My memory is a bit sketchy, but is it something to do with the fact that adenine and thymine are held together by two hydrogen bonds, but cytosine and guanine are held together by three hydrogen bodns and is therefore more stable ...
Guan has just learnt the four nucleobases in DNA: Adenine, Thymine, Cytosine and Guanine. Wait, GUANine. Guan is incredibly intrigued by this based named GUANine. Was it named after me? he thought to himself. Surely it must be, I am so smart. After countless hours of searching Google for the origins of Guanine, his search turned out futile. There was no results found for Wu Guanquns brilliant discovery of new nucleobase Guanine. Devastated, he turns back to his lego DNA play set and starts constructing DNA sequences. ATTGCCGATTGACT, Guan made, hmm, gene for awkwardness. GCTAGCTAGCGCGTAT, Guan made another gene sequence, hmm, gene for being weird. Guan starts off with an empty DNA string. He can then choose any one of four operations to do ...
Oxidative damage yields isolated electrons and their corresponding holes that can migrate along DNA. In the 6 July Nature Lewis et al. determine rate constants of ~5x107 s-1 and 5x106 s-1, respectively, for forward and return hole transport from a single guanine base to a double guanine base across a single adenine (Nature 2000, 406:51-53). These rates mean that electrons do not linger long enough to participate in strand-cleavage reactions. But the electrons move too slowly to avoid charge recombination, so DNA cannot act as a useful molecular wire. ...
مقاله ISI انگلیسی شماره 10645 - ترجمه نشده - موضوع : اقتصاد سلامت - 7 صفحه - سال انتشار : 2012 - منبع : الزویر ساینس دایرکت
Get an answer for DNA MoleculeUnder normal circumctances, it is not possible for adenine to pair up with guanine or cytosine, or for any other mismatches to occur. Describe the two factors that prevent a mismatch from occcuring. and find homework help for other Science questions at eNotes
Prevents viral reverse transcription of single-stranded RNA into double-stranded DNA, by inhibiting HIV reverse transcriptase ...
Looking for online definition of guanine analogues in the Medical Dictionary? guanine analogues explanation free. What is guanine analogues? Meaning of guanine analogues medical term. What does guanine analogues mean?
The O(6)-alkylguanine-DNA alkyltransferase inactivator O(6)-benzylguanine was administered to BALB/c mice either alone or before exposure to 1,3-bis(2-chloroethyl)-1-nitrosourea to study the role of the DNA repair protein O(6)-alkylguanine-DNA alkyltransferase in the protection of the testis against anti-cancer O(6)-alkylating agents. Exposure of the mice to 1, 3-bis(2-chloroethyl)-1-nitrosourea or O(6)-benzylguanine alone did not produce any marked testicular toxicity at the times studied. Testicular O(6)-alkylguanine-DNA alkyltransferase concentrations were assayed between 0 and 240 min after O(6)-benzylguanine treatment and were shown to be , 95% depleted 15 min after treatment with O(6)-benzylguanine and remained at , 95% at all the times assayed. Histological examination, the reduction in testicular mass and the induction of spermatogenic cell apoptosis showed that this depletion significantly potentiated 1, 3-bis(2-chloroethyl)-1-nitrosourea-induced testicular damage after treatment. Major ...
Maintenance therapy is associated with improved survival in non-small cell lung cancer (NSCLC), but few studies have compared active agents in this setting. In a phase III trial (AVAPERL trial) reported in the Journal of Clinical Oncology by Fabrice Barlesi, MD, PhD, of Aix Marseille University-Assistance Publique Hôpitaux de Marseille, and colleagues, patients with advanced nonsquamous NSCLC who had disease control after first-line treatment with platinum-based chemotherapy plus bevacizumab (Avastin) had significantly prolonged progression-free survival with maintenance bevacizumab/pemetrexed (Alimta) compared with bevacizumab alone.1 Toxicity was increased with bevacizumab/pemetrexed, although no new safety signals were observed.. Study Details. In this open-label multicenter trial, 376 patients with advanced nonsquamous NSCLC received first-line bevacizumab 7.5 mg/kg, cisplatin 75 mg/m2, and pemetrexed 500 mg/m2 once every 3 weeks for four cycles. Of these, 269 (72%) achieved disease control ...
TY - JOUR. T1 - Resistance-modifying agents. 8. Inhibition of O6-alkylguanine-DNA alkyltransferase by O6-alkenyl-, O6-cycloalkenyl-, and O6-(2-oxoalkyl)guanines and potentiation of temozolomide cytotoxicity in vitro by O6-(1-cyclopentenylmethyl) guanine. AU - Griffin, R. J.. AU - Arris, C. E.. AU - Bleasdale, C.. AU - Boyle, F. T.. AU - Calvert, A. H.. AU - Curtin, N. J.. AU - Dalby, C.. AU - Kanugula, S.. AU - Lembicz, N. K.. AU - Newell, D. R.. AU - Pegg, A. E.. AU - Golding, B. T.. PY - 2000/11/2. Y1 - 2000/11/2. N2 - A series of O6-allyl- and O6-(2-oxoalkyl)guanines were synthesized and evaluated, in comparison with the corresponding O6-alkylguanines; as potential inhibitors of the DNA-repair protein O6-alkylguanine-DNA alkyltransferase (AGT). Simple O6-alkyl- and O6-cycloalkylguanines were weak AGT inactivators compared with O6-allylguanine (IC50 = 8.5 ± 0.6 μM)with IC50 values ranging from 100 to 1000 μM. The introduction of substituents at C-2 of the allyl group of O6-allylguanine ...
Lomeguatrib (CAS: 192441-08-0) is a modified guanine base, which can repress the activity of DNA repair protein O(6)-alkylguanine-DNA alkyltransferase (MGMT) with an IC50 value of 6 nM.
TY - JOUR. T1 - Inactivation and degradation of O6-alkylguanine-DNA alkyltransferase after reaction with nitric oxide. AU - Liu, Liping. AU - Xu-Welliver, Meng. AU - Kanugula, Sreenivas. AU - Pegg, Anthony E.. PY - 2002/6/1. Y1 - 2002/6/1. N2 - O6-Alkylguanine-DNA alkyltransferase (AGT) plays a critical role in protection from the carcinogenic effects of simple alkylating agents by repairing O6-alkylguanine adducts via a direct transfer reaction. Nitric oxide (NO) or species derived from it are known to be able to initiate neoplastic growth and cannot only damage DNA, either directly or via the formation of intermediates such as nitrosamines, but can also inhibit some DNA repair processes. We have studied the inactivation of AGT by NO in detail in vitro and in vivo using wild-type human AGT (hAGT) and mutants at key residues. Our results show that hAGT is readily but reversibly inactivated by the formation of S-nitrosylcysteine at Cys-145, which is the alkyl acceptor site. The facile reaction of ...
Pemetrexed-based chemotherapy may be another option for patients progressing on the second generation ALK-TKI. The PFS with pemetrexed based therapy for ALK-rearranged NSCLC patients is significantly longer than in patients without ALK rearrangements or with either EGFR or KRAS mutant [36-38]. Besides, pemetrexed was shown to be superior to docetaxel in both ORR (29% vs. 7%, respectively) and PFS (4.2 months vs. 2.6 months, respectively) for ALK-rearrangement NSCLC patients progressing on platinum-based chemotherapy [5]. All of these implied that pemetrexed should be preferentially considered for the treatment of ALK-rearrangement lung adenocarcinoma. However, the overall prognosis of patients with ALK-rearrangement NSCLC was still not encouraged.. Bevacizumab shows encouraging efficacy as the first or second-line therapy for patients with non-squamous NSCLC in some studies [39]. The phase III BEYOND trial compared the efficacy of carboplatin/paclitaxel plus placebo and carboplatin/paclitaxel ...
The combination of pemetrexed and cisplatin shows good clinical activity against mesothelioma and lung cancer. In order to study the potential cellular basis for this, and provide leads as to how to optimize the combination, we studied the schedule-dependent cytotoxic effects of pemetrexed and cisplatin against four human cancer cell lines in vitro. Tumor cells were incubated with pemetrexed and cisplatin for 24 h at various schedules. The combination effects after 5 days were analyzed by the isobologram method. Both simultaneous exposure to pemetrexed and cisplatin for 24 h and sequential exposure to cisplatin for 24 h followed by pemetrexed for 24 h produced antagonistic effects in human lung cancer A549, breast cancer MCF7, and ovarian cancer PA1 cells and additive effects in colon cancer WiDr cells. Pemetrexed for 24 h followed by cisplatin for 24 h produced synergistic effects in MCF7 cells, additive/synergistic effects in A549 and PA1 cells, and additive effects in WiDr cells. Cell cycle ...
Guanine is among the five nucleobases that is found in DNA and RNA. The formula of guanine is C5H5N5O, and is a planar and bicyclic molecule. Guanine has two forms, keto and enol forms. The keto form is the major form. Guanine, like adenine, is a derivative of purine and binds to cytosine through 3 hydrogen bonds. The amino group in the cytosine is the hydrogen donor and the C2 carbonyl and the N3 amine are the hydrogen-bond acceptors. In Guanine, the group at C6 acts as the hydrogen accepter, and the group at N1 and the amino group at C2 act as the hydrogen donors. The related nucleoside containing guanine and ribose is called guanosine and guanine bound to deoxyribose sugar is called deoxyguanosine. Guanine is capable of being hydrolyzed by strong acids to form ammonia, carbon monoxide, carbon dioxide, and glycine. Guanine oxidizes more readily than adenine, another purine-derivative nitrogenous base in nucleic acids. Guanine has a high melting point of 350°C due to the intermolecular ...
The protein O 6-alkylguanine-DNA alkyltransferase(alkyltransferase) is involved in the repair of O 6-alkylguanine and O 4-alkylthymine in DNA and plays an important role in most organisms in attenuating the cytotoxic and mutagenic effects of certain classes of alkylating agents. A genomic clone encompassing the Drosophila melanogaster alkyltransferase gene ( DmAGT ) was identified on the basis of sequence homology with corresponding genes in Saccharomyces cerevisiae and man. The DmAGT gene is located at position 84A on the third chromosome. The nucleotide sequence of DmAGT cDNA revealed an open reading frame encoding 194 amino acids. The MNNG-hypersensitive phenotype of alkyltransferase-deficient bacteria was rescued by expression of the DmAGT cDNA. Furthermore, alkyltransferase activity was identified in crude extracts of Escherichia coli harbouring DmAGT cDNA and this activity was inhibited by preincubation of the extract with an oligonucleotide containing a single O6-methylguanine lesion. ...
In KEYNOTE-189, first-line pembrolizumab plus pemetrexed-platinum significantly improved overall survival (OS) and progression-free survival (PFS) compared with placebo plus pemetrexed-platinum in patients with metastatic nonsquamous nonsmall-cell lung cancer (NSCLC), irrespective of tumor programmed death-ligand 1 (PD-L1) expression. We report an updated analysis from KEYNOTE-189 (ClinicalTrials.gov: NCT02578680).Patients were randomly assigned (2:1) to receive pemetrexed and platinum plus pembrolizumab (n = 410) or placebo (n = 206) every 3 weeks for 4 cycles, then pemetrexed maintenance plus pembrolizumab or placebo for up to a total of 35 cycles. Eligible patients with disease progression in the placebo-combination group could cross over to pembrolizumab monotherapy. Response was assessed per RECIST (version 1.1) by central review. No alpha was assigned to this updated analysis.As of September 21, 2018 (median follow-up, 23.1 months), the updated median (95% CI) OS was 22.0 (19.5 to 25.2) ...
In the phase III AURA3 trial reported in The New England Journal of Medicineby Mok et al, osimertinib (Tagrisso) significantly improved progression-free survival (PFS) vs platinum/pemetrexed (Alimta) among patients with epidermal growth factor receptor (EGFR) T790M-positive non-small cell lung cancer (NSCLC) progressing during first-line EGFR tyrosine kinase inhibitor therapy. Osimertinib is an EGFR tyrosine kinase inhibitor that is selective for both EGFR tyrosine kinase inhibitor-sensitizing and T790M resistance mutations.. Study Details. In this open-label international trial, 419 patients were enrolled from 126 sites between August 2014 and September 2015 and randomized 2:1 to receive oral osimertinib at 80 mg once daily (n = 279) or intravenous pemetrexed at 500 mg/m2 plus either carboplatin at target area under the curve = 5 (AUC5) or cisplatin at 75 mg/m2 every 3 weeks for up to 6 cycles; maintenance pemetrexed was allowed. Randomization was stratified for Asian vs non-Asian race. The ...
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Alimta - Get up-to-date information on Alimta side effects, uses, dosage, overdose, pregnancy, alcohol and more. Learn more about Alimta
Guanosines with substituents at the 8-position can provide useful fluorescent probes that effectively mimic guanine residues even in highly demanding model systems such as polymorphic G-quadruplexes and duplex DNA. Here, we report the synthesis and photophysical properties of a small family of 8-substituted-2′-deoxyguanosines that have been incorporated into the human telomeric repeat sequence using phosphoramidite chemistry. These include 8-(2-pyridyl)-2′-deoxyguanosine (2PyG), 8-(2-phenylethenyl)-2′-deoxyguanosine (StG) and 8-[2-(pyrid-4-yl)-ethenyl]-2′-deoxyguanosine (4PVG). On DNA folding and stability, 8-substituted guanosines can exhibit context-dependent effects but were better tolerated by G-quadruplex and duplex structures than pyrimidine mismatches. In contrast to previously reported fluorescent guanine analogs, 8-substituted guanosines exhibit similar or even higher quantum yields upon their incorporation into nucleic acids (Φ = 0.02-0.45). We have used these highly emissive ...
Drug information for Alimta (pemetrexed). Includes side effects, cost, dosage, drug interactions, warnings prescribing Information (package insert) for mesothelioma and Nonsquamous Non-Small Cell Lung Cancer (NSCLC).
Entecavir - Get up-to-date information on Entecavir side effects, uses, dosage, overdose, pregnancy, alcohol and more. Learn more about Entecavir
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Yavin, Eylon and Boal, Amie K. and Stemp, Eric D. A. et al. (2005) Protein-DNA charge transport: Redox activation of a DNA repair protein by guanine radical. Proceedings of the National Academy of Sciences of the United States of America, 102 (10). pp. 3546-3551. ISSN 0027-8424. PMCID PMC553321. https://resolver.caltech.edu/CaltechAUTHORS:YAVpnas05 ...
Abstract: To investigate the molecular mechanism of the antitumour activity of cisplatin, ab initio Hartree-Fock pseudo potential calculations have been performed for some Pt(II) complexes with the guanine nucleic base. We propose that cisplatin binding to guanine in DNA leads to a point mutation as the latter is the only change that the nucleic acid could remember after replication. Two ways of producing the point mutation are examined. The first is shifting the keto-enol tautomerization of guanine towards the enol form (rare in DNA) in the presence of cisplatin. The second is the action of cisplatin on the guaninecytosine pairing in DNA through binding to the O6 site of guanine which is involved in one of three hydrogen bonds between these nucleic bases. For this purpose the complex of cis-Pt(NH3)32+ and the hydrogen-bonded formamide-formamide pair has been calculated. The results obtained suggest, first, that the keto-enol tautomerization is not subject to crucial change in the presence of ...
Buy Famvir Online! Famvir is a guanine analogue used to treat herpes virus infections. Famvir does not cure or stop the spread of herpes infections. Famvir was approved for use by the FDA in June 1994.
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Aim: To assess the long term efficacy and safety of Entecavir in the treatment of CHB in Asian-Arabic patients with genotype D, for both nucleoside-naïve as well as ..
Two seperate strands are held together by hydrogen bonds. They wind around each other in a double helix.. DNA forms complementary base pairing as Adenine always pairs wirh Thymine and Guanine always pairs with Cytosine.. Adenine and Guanine are large with 2 rings they are the purines and Cytosine and Thymine have 1 rings. One large pairs with smaller base so width of a base pair is always the same.. Hydrogen bonding is due to the shape of the molecules two Hydrogen bonds form between Adenine and Thymine whereas three form between Cytosine and Guanine.. ...
The present invention relates to a preparation method for a medicine and an intermediate compound thereof, specifically, relates to a preparation method for entecavir, an intermediate compound thereo
Treatment with pemetrexed, carboplatin and bevacizumab followed by maintenance pemetrexed and bevacizumab (Pem+Cb+B) is no better than standard therapy with paclitaxel, carboplatin and bevacizumab followed by bevacizumab ...
Chemical structures of G-quartets and quadruplexes. (A) Anticonformation (top left) and syn conformation (top right) of guanosine. (B) Inosine (left) and 7-deaz
Ganciclovir is a synthetic acyclic-DNA guanine derivative, where the C2 carbon bond is absent. Ganciclovir Triphosphate (ganciclovir-TP, GCV-TP), the active metabolite of ganciclovir, is thought to disrupt viral DNA synthesis by competitive inhibition of
Research and Markets: Investigation Report on Chinas Pemetrexed Market, 2009-2018: A Multi-Targeted Antimetabolite Antitumor Drug
The transcribed strand of S. cattleya can be inferred to have an average guanine content of 37.85%, since the message strand has a cytosine content of 37.85%. In B. burgdorferi, the transcribed-strand guanine has dropped to 12.17%. The difference between the two is 25.68%. On the message strand, adenine content goes from 13.59% for S. cattleya to 38.71% for B. burgdorferi, a difference of 25.12%. The implication is that if organisms evolve along the general path of the regression line in the above graph, all of the increase in message-strand adenine content can be accounted for by the loss in transcribed-strand guanine content. (The loss of guanine, in this example, was 25.68%, which is comparable to the increase of adenine, 25.12%, differing by only two parts per hundred.) Other organisms show a similar pattern of the change in transcribed-strand guanine equaling the change in message-strand adenine ...
© 2015 Elsevier Inc. Monofunctional Pt(II) complexes bind to G residues in DNA and, if the carrier ligands are bulky, cause DNA structural distortions that lead to anticancer activity. We assessed the steric effects of the tridentate carrier ligand, N(H)6-Medpa (N-(6-methyl-2-picolyl)-N-(2-picolyl)amine), bearing a 6-methyl group and a 6′-proton projecting toward the nucleobase in Pt(N(H)6-Medpa)G adducts (G = 9-ethylguanine, 3′-GMP, 5′-GMP, 5′-GTP). Pt(N(H)6-Medpa)G adducts form syn and anti rotamers with the guanine O6 and the central N-H of N(H)6-Medpa on the same or opposite side of the coordination plane, respectively. Pt(N(H)6-Medpa)G adducts have some properties (ease of rotamer interchange and extent of conversion to bis adducts, Pt(N(H)6-Medpa)G2) intermediate to properties reported for analogs having a tridentate ligand with zero or two methyl groups. However, in comparison, the syn rotamer of Pt(N(H)6-Medpa)G adducts has an unexpectedly high abundance. This result is attributable to
879-08-3 - WDOYBEPLTCFIRQ-UHFFFAOYSA-N - 9-Ethylguanine - Similar structures search, synonyms, formulas, resource links, and other chemical information.
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1FJB: Structural Studies of the Ionizing Radiation Adduct 7,8-Dihydro-8-Oxoadenine (A Oxo) Positioned Opposite Thymine and Guanine in DNA Duplexes
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... guanine. Guanine was first obtained from guano by Julius Bodo Unger [de], who described it as xanthine in 1844. After he was ... "Guanine". mindat.org. Retrieved 11 August 2019. Partington, J. R (1964). History of Chemistry. London: Macmillan Education, ... corrected, Bodo Unger published it with the new name of "guanine" in 1846. Chicken manure Phosphorite Szpak, Paul; Millaire, ...
hypoxanthine/guanine phosphoribosyl transferase (HGPRT). IMP guanine. hypoxanthine/guanine phosphoribosyl transferase (HGPRT). ... There are two types of phosphoribosyltransferases: adenine phosphoribosyltransferase (APRT) and hypoxanthine-guanine ...
... is a purine nucleoside comprising guanine attached to a ribose (ribofuranose) ring via a β-N9-glycosidic bond. ... When guanine is attached by its N9 nitrogen to the C1 carbon of a deoxyribose ring it is known as deoxyguanosine. ...
Here, four guanine bases form a flat plate and these flat four-base units then stack on top of each other, to form a stable G- ... Adenine pairs with thymine and guanine pairs with cytosine, forming A-T and G-C base pairs.[18][19] ... These guanine-rich sequences may stabilize chromosome ends by forming structures of stacked sets of four-base units, rather ... Building blocks of DNA (adenine, guanine, and related organic molecules) may have been formed extraterrestrially in outer space ...
Guanine (G) T Thymine (T) N A, C, G or T M A or C ...
Guanine preferentially binds. Subsequent to formation of [PtCl(guanine-DNA)(NH3)2]+, crosslinking can occur via displacement of ... the other chloride, typically by another guanine. Cisplatin crosslinks DNA in several different ways, interfering with cell ...
The ethyl group of EMS reacts with guanine in DNA, forming the abnormal base O6-ethylguanine. During DNA replication, DNA ... It produces random mutations in genetic material by nucleotide substitution; particularly by guanine alkylation. This typically ...
30 guanine; 35 urea, 40 uricite Stuart J. Mills; Frédéric Hatert; Ernest H. Nickel & Giovanni Ferraris (2009). "The ...
The inactive form of GTPases (GDP-form) are activated by a class of proteins called Guanosine nucleotide exchange factors (GEFs). GEFs catalyse nucleotide exchange by encouraging the release of GDP from the small GTPase (by displacement of the small GTPase-associated Mg2+ ion) and GDP's replacement by GTP (which is in at least a 10-fold excess within the cell) . Inactivation of the active small GTPase is achieved through hydrolysis of the GTP by the small GTPase's intrinsic GTP hydrolytic activity. ...
... t-RNA guanine transglycosylase (shigellosis); trypanothione reductase (African sleeping sickness). Supramolecular nanosystems ...
The similar structures of guanine:cytosine and adenine:thymine base pairs is illustrated. The base pairs are held together by ... the amount of guanine is equal to cytosine and the amount of adenine is equal to thymine. A visit by Erwin Chargaff to England ...
A purine base always pairs with a pyrimidine base (guanine (G) pairs with cytosine (C) and adenine (A) pairs with thymine (T) ... The nitrogen bases adenine and guanine are purine in structure and form a glycosidic bond between their 9 nitrogen and the 1' - ... The purines are adenine and guanine. Purines consist of a double ring structure, a six-membered and a five-membered ring ... Nucleotides consist of 3 components: Nitrogenous base Adenine Guanine Cytosine Thymine (present in DNA only) Uracil (present in ...
Guanine nucleotide-binding protein subunit alpha-15 is a protein that in humans is encoded by the GNA15 gene. G15α is a member ... GUANINE NUCLEOTIDE-BINDING PROTEIN, ALPHA-15; GNA15 at OMIM. Retrieved JULY 25, 2019.. ...
Guanine nucleotide-binding protein subunit alpha-14 is a protein that in humans is encoded by the GNA14 gene. G14α is a member ... GUANINE NUCLEOTIDE-BINDING PROTEIN, ALPHA-14; GNA14 at OMIM. Retrieved JULY 25, 2019.. ...
In the guanine nucleotide pathway, there are 2 enzymes involved in converting IMP to GMP, namely IMP dehydrogenase (IMPD1), ... "Entrez Gene: GMPS guanine monphosphate synthetase". Page T, Bakay B, Nyhan WL (1984). "Human GMP synthetase". The International ... IMP is the branch point metabolite at which point the pathway diverges to the synthesis of either guanine or adenine ...
Guanine nucleotide-binding protein G(t) subunit alpha-3, also known as gustducin alpha-3 chain, is a protein subunit that in ... "Entrez Gene: guanine nucleotide binding protein". Oldham WM, Van Eps N, Preininger AM, et al. (2006). "Mechanism of the ...
The guanine + cytosine content is ~50%. It has terminally redundant sequences and is nonpermuted. By weight, the genome ...
Cytosine is deaminated to uracil, which base pairs with Adenine instead of Guanine. Deamination of Guanine is not mutagenic. ... guanine. If this happens during DNA replication, a guanine will be inserted as the opposite base analog, and in the next DNA ... It can cause deamination of the amino groups of Adenine, Guanine and Cytosine. Adenine is deaminated to hypoxanthine, which ... and cytosine and guanine are mixed amine and carbonyl (inverted in respect to each other). The precise reason why there are ...
One hydrogen bond from the Watson-Crick base pair is maintained (guanine O6 and cytosine N4) and the other occurs between ... Hoogsteen base pairs occur between adenine (A) and thymine (T); and guanine (G) and cytosine(C); similarly to Watson-Crick base ... The 4 main examples are guanine-uracil (G-U), hypoxanthine-uracil (I-U), hypoxanthine-adenine (I-A), and hypoxanthine-cytosine ... and guanine (G) -- cytosine (C) in both DNA and RNA). There are three main types of non-canonical base pairs: those stabilized ...
Some 1,2-dicarbonyl compounds are able to react with single-stranded guanine (G) at N1 and N2, forming a five-membered ring ... Kethoxal causes the modification of guanine, specifically altering the N1 and the exocyclic amino group (N2) simultaneously by ... Glyoxal, methylglyoxal, and phenylglyoxal, which all carry the key 1,2-dicarbonyl moiety, all react with free guanines similar ... Muhlbacher J, Lafontaine DA (2007). "Ligand recognition determinants of guanine riboswitches". Nucleic Acids Research. 35 (16 ...
MBD4 specifically catalyzes the removal of T and U paired with guanine (G) within CpG sites. This is an important repair ... Xanthine formed from deamination of guanine. (Thymidine products following deamination of 5-methylcytosine are more difficult ...
RNA (guanine-9-) methyltransferase domain containing 2 is a protein that in humans is encoded by the RG9MTD2 gene. The gene is ... "RNA (guanine-9-) methyltransferase domain containing 2". Retrieved 2011-12-06. "Clinical chemistry data for Rg9mtd2". Wellcome ...
"Entrez Gene: GNA11 guanine nucleotide binding protein (G protein), alpha 11 (Gq class)". 139313 GUANINE NUCLEOTIDE-BINDING ... Guanine nucleotide-binding protein subunit alpha-11 is a protein that in humans is encoded by the GNA11 gene. Together with ... Jiang M, Pandey S, Tran VT, Fong HK (1991). "Guanine nucleotide-binding regulatory proteins in retinal pigment epithelial cells ...
It is a methylated version of guanine. The 7-methylguanine nucleoside is called 7-methylguanosine. v t e. ...
Structural aspects of guanine-nucleotide-binding sites". European Journal of Biochemistry / FEBS. 155 (1): 167-71. doi:10.1111/ ...
139313 GUANINE NUCLEOTIDE-BINDING PROTEIN, ALPHA-11; GNA11 at OMIM. Retrieved January 1, 2015. "Entrez Gene: GNAQ guanine ... Guanine nucleotide-binding protein G(q) subunit alpha is a protein that in humans is encoded by the GNAQ gene. Together with ... Guanine nucleotide-binding proteins are a family of heterotrimeric proteins that couple cell surface, 7-transmembrane domain ... Tall GG, Krumins AM, Gilman AG (March 2003). "Mammalian Ric-8A (synembryn) is a heterotrimeric Galpha protein guanine ...
Structural aspects of guanine-nucleotide-binding sites". European Journal of Biochemistry / FEBS. 155 (1): 167-71. doi:10.1111/ ...
The conformation is considered to be open, when no guanine nucleotide is bound to the active site in EF-Tu. The EF-Ts chain ... Helix D of EF-Tu must interact with the N-terminal domain of EF-Ts for guanine nucleotide exchange. A recent study researched ... EF-Ts functions as guanine nucleotide exchange factor, it catalyzes the reaction of EF-Tu*GDP ( inactive form) to EF-Tu*GTP ( ... In Eukaryotes EF-1 performs the same function, and the mechanism for guanine nucleotide exchange is nearly identical, as EF-Ts ...
guanine One of the four main nucleobases present in DNA and RNA. Guanine forms a base pair with cytosine. guanine-cytosine ... Cytosine forms a base pair with guanine. Contents: Top 0-9 A B C D E F G H I J K L M N O P Q R S T U V W X Y Z degeneracy The ... Adenine (A) and guanine (G) are classified as purines. putative gene A specific nucleotide sequence suspected to be a ... A set of five distinct nitrogenous bases - adenine (A), guanine (G), cytosine (C), thymine (T), and uracil (U) - are especially ...
... guanine is paired with cytosine. The guanine nucleoside is called guanosine. With the formula C5H5N5O, guanine is a derivative ... Guanine can be hydrolyzed with strong acid to glycine, ammonia, carbon dioxide, and carbon monoxide. First, guanine gets ... 10NH3 + 2CH4 + 4C2H6 + 2H2O → 2C5H8N5O (guanine) + 25H2 A Fischer-Tropsch synthesis can also be used to form guanine, along ... because the guanine in the droppings makes the skin look paler. Guanine crystals are rhombic platelets composed of multiple ...
Guanine deaminase also known as cypin, guanase, guanine aminase, GAH, and guanine aminohydrolase is an aminohydrolase enzyme ... Guanine+deaminase at the US National Library of Medicine Medical Subject Headings (MeSH) Overview of all the structural ... Hitchings GH, Falco EA (Oct 1944). "The Identification of Guanine in Extracts of Girella Nigricans: The Specificity of Guanase ... which converts guanine to xanthine. Cypin is a major cytosolic protein that interacts with PSD-95. It promotes localized ...
... is a 2-aminopurines (CHEBI:20702) guanine (CHEBI:16235) is a oxopurine (CHEBI:25810) guanine (CHEBI:16235 ... guanine (CHEBI:16235). 9-[2-(phosphonomethoxy)ethyl]guanine (CHEBI:7880) has functional parent guanine (CHEBI:16235). N2,3- ... guanine (CHEBI:16235) has parent hydride 9H-purine (CHEBI:35589) guanine (CHEBI:16235) has role Escherichia coli metabolite ( ... guanine (CHEBI:16235) has role algal metabolite (CHEBI:84735) guanine (CHEBI:16235) has role human metabolite (CHEBI:77746) ...
Synonyms: z-METTL1 tRNA(m7G46)-methyltransferase (zebrafish) miRNA (guanine-N(7)-)-methyltransferase (zebrafish) tRNA (guanine( ... A tRNA (guanine-N(7)-)-methyltransferase that is encoded in the genome of zebrafish. [ PRO. :. DNx OMA. :. Q5XJ57 ] ... tRNA (guanine-N(7)-)-methyltransferase and only_in_taxon some Danio rerio ... tRNA (guanine-N(7)-)-methyltransferase (zebrafish). Go to external page http://purl.obolibrary.org/obo/PR_Q5XJ57 Copy ...
The deprotonated guanine-cytosine base pair. Maria C. Lind, Partha P. Bera, Nancy A. Richardson, Steven E. Wheeler, Henry F. ... The deprotonated guanine-cytosine base pair. Maria C. Lind, Partha P. Bera, Nancy A. Richardson, Steven E. Wheeler, Henry F. ... The deprotonated guanine-cytosine base pair. Maria C. Lind, Partha P. Bera, Nancy A. Richardson, Steven E. Wheeler, and Henry F ... Luo et al. (12) found the AEA of guanine with a hydrogen abstracted from the N9 site to be the highest, at 2.99 eV. Luo et al. ...
Definition of guanine deaminase. Provided by Stedmans medical dictionary and Drugs.com. Includes medical terms and definitions ... guanine deaminase. Definition: a deaminase of the liver that catalyzes hydrolysis of guanine into xanthine and ammonia; the ... Synonym(s): guanase, guanine aminase. Further information. Always consult your healthcare provider to ensure the information ...
Electrochemical Characterization of Guanine Quadruplexes. A.-M. Chiorcea-Paquim, P. Santos, V.C. Diculescu, R. Eritja and A.M. ... Guanine, Xanthine and Uric Acid Assemblies: Comparative Theoretical and Experimental Studies. Gábor Paragi, János Szolomájer, ... Morphological Heterogeneity of Supramolecular G-DNA Polymers Derived from Guanine Rich Oligonucleotides. T.C. Marsh, Z.M. ... Nanopatterning the Surface with Ordered Supramolecular Architectures: Controlling the Self-assembly of Guanine-based Hydrogen- ...
xanthine-guanine phosphoribosyltransferase. YP_010287.1. *EC 2.4.2.22. *catalyzes the conversion of guanine, xanthine and, to a ... xanthine-guanine phosphoribosyltransferase. Locus tag. DVU1066. Gene type. protein coding. RefSeq status. REVIEWED. Organism. ... gpt xanthine-guanine phosphoribosyltransferase [ Desulfovibrio vulgaris str. Hildenborough ] Gene ID: 2794778, updated on 30- ... YP_010287.1 xanthine-guanine phosphoribosyltransferase [Desulfovibrio vulgaris str. Hildenborough]. See identical proteins and ...
HYPOXANTHINE-GUANINE-XANTHINE PHOSPHORIBOSYLTRANSFERASE. A, B. 183. Tritrichomonas suis. Mutation(s): 0 Gene Names: HPT. EC: ... HYPOXANTHINE-GUANINE-XANTHINE PHOSPHORIBOSYLTRANSFERASE (HGXPRTASE). *DOI: 10.2210/pdb1HGX/pdb. *Classification: TRANSFERASE ( ... The crystal structure of the hypoxanthine-guanine-xanthine phosphoribosyltransferase (HGXPRTase) from Tritrichomonas foetus has ... The crystal structure of the hypoxanthine-guanine-xanthine phosphoribosyltransferase (HGXPRTase) from Tritrichomonas foetus has ...
mRNA cap guanine-N7 methyltransferase isoform 2 [Homo sapiens] mRNA cap guanine-N7 methyltransferase isoform 2 [Homo sapiens]. ... RNA guanine-7 methyltransferase catalyzes the methylation of cytoplasmically recapped RNAs. [Nucleic Acids Res. 2017] RNA ... mRNA cap guanine-N7 methyltransferase isoform 2 [Homo sapiens]. NCBI Reference Sequence: NP_003790.1 ... Crystal Structure Of Mrna Cap Guanine-n7 Methyltransferase (rnmt) In Complex With Sinefungin PDB: 3EPP ...
Ozerov I.V., Balitskaya E.D., Efremov R.G. (2012) System-Specific Scoring Functions: Application to Guanine-Containing Ligands ... underlying efficiency of such scoring functions and demonstrates the related quantitative approaches by the examples of guanine ...
Origin and meaning of guanine: 1846, from guano, from which the chemical first was isolated, + chemical suffix -ine (2). ... ... guanine (n.). 1846, from guano, from which the chemical first was isolated, + chemical suffix -ine (2). ... guanine. (. n.. ). a purine base found in DNA and RNA. ; pairs with cytosine. ; ...
Converts guanine to guanosine monophosphate, and hypoxanthine to inosine monophosphate. Transfers the 5-phosphoribosyl group ...
Guanine structure in templates is not quite correct. See: http://itmag.es/65eHW (There are some problems with itmages.ru, but ... Wrong guanine structure Bug #1090777 reported by Ilya Flyamer on 2012-12-15. ... Guanine structure in templates is not quite correct. See: http://. itmag.es/. 65eHW (There are some problems with itmages.ru, ... en.wikipedia.org/wiki/Guanine Ref. Project homepage: https://savannah.nongnu.org/projects/gchemutils/ ...
tRNA-guanine transglycosylase from Escherichia. Overexpression, purification and quaternary structure. J.Mol.Biol. 231:489-497 ... tRNA-guanine transglycosylase from Escherichia coli: gross tRNA structural requirements for recognition. Biochemistry 32:5239- ... tRNA-guanine transglycosylase from Escherichia coli: molecular mechanism and role aspartate 89. Biochemistry 40:14123-14133 ...
The Guanine Market research report is a professional and in-depth study on the current state of the Guanine industry. ... In this Guanine Market analysis, traders and distributors analysis is given along with contact details. For material and ... The Guanine industry consumption for major regions is given. Additionally, type wise and application wise consumption figures ... Further in the report, the Guanine Market is examined for price, cost and gross. These three points are analysed for types, ...
Buy and download Guanine, and other high-quality fonts for Mac and Windows Publishing. Fonts are available in TrueType, ...
An almost complete deficiency of the enzyme hypoxanthine guanine phosphoribosyl transferase (HPRT) is known to be the cause of ... An almost complete deficiency of the enzyme hypoxanthine guanine phosphoribosyl transferase (HPRT) is known to be the cause of ... Detection of Hypoxanthine Guanine Phosphoribosyl Transferase Heterozygotes by Thin Layer Chromatography and Autoradiography. ... Page T., Bakay B., Nyhan W.L. (1984) Detection of Hypoxanthine Guanine Phosphoribosyl Transferase Heterozygotes by Thin Layer ...
Browse our Guanine deaminase Protein catalog backed by our Guarantee+. ... Guanine deaminase Proteins available through Novus Biologicals. ...
Converts guanine to guanosine monophosphate, and hypoxanthine to inosine monophosphate. Transfers the 5-phosphoribosyl group ... guanine salvage Source: UniProtKB. *hypoxanthine metabolic process Source: RGDInferred from direct assayi*. "Metabolism of ... Hypoxanthine-guanine phosphoribosyltransferaseAdd BLAST. 218. Amino acid modifications. Feature key. Position(s). Description ... guanine phosphoribosyltransferase activity Source: UniProtKB. *hypoxanthine phosphoribosyltransferase activity Source: RGD ,p> ...
... guanine nucleotide exchange factors include Comparing the Affinity of GTPase-binding Proteins using Competition Assays, ... Guanine Nucleotide Exchange Factors: Protein factors that promote the exchange of Gtp for Gdp bound to Gtp-binding proteins. ...
With the formula C5H5N5O, guanine is a derivative of purine, consisting of a fused pyrimidine-imidazole ring system with ... Guanine is one of the five main nucleobases found in the nucleic acids DNA and RNA; the others being adenine, cytosine, thymine ... Guanine is one of the five main nucleobases found in the nucleic acids DNA and RNA; the others being adenine, cytosine, thymine ... With the formula C5H5N5O, guanine is a derivative of purine, consisting of a fused pyrimidine-imidazole ring system with ...
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... the human homologue of the Drosophila guanine-nucleotide-releasing factor for Ras, which is essential for control of Ras ... Guanine-nucleotide-releasing factor hSos1 binds to Grb2 and links receptor tyrosine kinases to Ras signalling. *N. Li1, ... Li, N., Batzer, A., Daly, R. et al. Guanine-nucleotide-releasing factor hSos1 binds to Grb2 and links receptor tyrosine kinases ... the human homologue of the Drosophila guanine-nucleotide-releasing factor for Ras, which is essential for control of Ras ...
After fixing the DNA, they were able to obtain an image of about 140 bases in which bright spots that correspond to guanine ... Another way to speed up the process would be to distinguish guanine by comparing two images obtained at a certain voltage, or ... Researchers in Japan have used scanning tunneling microscopy to visualize the positions of guanine bases in long, single- ... Scanning Tunneling Microscope Maps Guanines in Single DNA Strands Jul 14, 2009 ...
... guanine nucleotides include Live Cell Imaging of Bacillus subtilis and Streptococcus pneumoniae using Automated Time-lapse ... Guanine Nucleotides: Live Cell Imaging of Bacillus subtilis and Streptococcus pneumoniae using Automated Time-lapse Microscopy ...
... a complex that has guanine nucleotide exchange factor (GEF) activity and regulates autophagy (PubMed:27193190, PubMed:27103069 ... Component of the C9orf72-SMCR8 complex, a complex that has guanine nucleotide exchange factor (GEF) activity and regulates ... sp,Q96LT7,CI072_HUMAN Guanine nucleotide exchange C9orf72 OS=Homo sapiens OX=9606 GN=C9orf72 PE=1 SV=2 ...
... Author(s). Lippard, Stephen J.; Johnstone, ... "The Chiral Potential of Phenanthriplatin and Its Influence on Guanine Binding." Journal of the American Chemical Society 136, ... the origin of which stems from an intramolecular interaction between the carbonyl oxygen of the platinated guanine base and a ...
Telomeric guanine-quadruplex molecules. (a) Schematic drawing of a parallel guanine-quadruplex from Stylonychia telomeric DNA d ... G4T4G4). (b) The quadruplex is stabilized by guanine quartet layers of four cyclically hydrogen-bonded guanine residues ( ... Evidence for Guanine-Quadruplex DNA in the scFv-DNA Complexes.. We then isolated the complex of scFv Sty3 bound to the parallel ... Telomeric guanine-quadruplex DNA has been shown to form in vitro under physiological conditions (6-8). It has been suggested ...
  • Guanine-based purines (GBPs), including the nucleotides guanosine 5′-triphosphate (GTP), guanosine 5′-diphosphate (GDP) and guanosine 5′-monophosphate (GMP), the nucleoside guanosine (GUO) and the nucleobase guanine (GUA) have been traditionally characterized as modulators of intracellular processes, especially considering their role in G protein dependent signal transduction. (frontiersin.org)
  • Along with guanine, it is involved in the formation of nucleotides into nucleic acids. (differencebetween.net)
  • 1. Our DNA and RNA are made up of nucleotides, in which adenine and guanine are purine-based. (differencebetween.net)
  • High affinity binding of guanine nucleotides and the ability to hydrolyze bound GTP to GDP are characteristics of an extended family of intracellular proteins. (hmdb.ca)
  • The binding of hormones to receptors that activate phospholipase C is decreased by guanine nucleotides and these hormones also stimulate a high-affinity GTPase activity in cell membranes. (hmdb.ca)
  • Effects of hormones on phospholipase C activity in cell-free preparations are dependent on the presence of guanine nucleotides. (hmdb.ca)
  • When combined with the sugar ribose in a glycosidic linkage, guanine forms a derivative called guanosine (a nucleoside), which in turn can be phosphorylated with from one to three phosphoric acid groups, yielding the three nucleotides nucleotide , organic substance that serves as a monomer in forming nucleic acids. (thefreedictionary.com)
  • Analogous nucleosides and nucleotides are formed from guanine and deoxyribose. (thefreedictionary.com)
  • The binding of guanine nucleotides was found to correlate with the loss of endogenous nucleotide from the rap1 protein, which was rapid in the absence of Mg2+. (biochemj.org)
  • Because the association of cytosolic ARF onto vesicle membranes is coincident with GTP activation, we searched the genome of L. pneumophila for proteins that had homology to ARF-specific guanine nucleotide exchange factors (GEFs) ( 16 ). (sciencemag.org)
  • The Vav proteins are guanine exchange factors (GEFs) that trigger the activation of the Rho GTPases in general and the Rac family in particular. (jneurosci.org)
  • This hSos1 domain specifically stimulated guanine nucleotide exchange on mammalian Ras proteins in vitro. (sciencemag.org)
  • Guanine nucleotide-binding regulatory proteins may be involved in the activation of phospholipases C and A2 by hormones and other ligands. (hmdb.ca)
  • Guanine nucleotide-binding proteins (G proteins) function as transducers downstream of G protein-coupled receptors (GPCRs), such as the photoreceptor RHO. (uniprot.org)
  • The C-terminal half of tamalin also bound to cytohesins, the members of guanine nucleotide exchange factors (GEFs) specific for the ADP-ribosylation factor (ARF) family of small GTP-binding proteins. (jneurosci.org)
  • We show that TCTPs form a structural superfamily with the Mss4/Dss4 family of proteins, which bind to the GDP/GTP free form of Rab proteins (members of the Ras superfamily) and have been termed guanine nucleotide-free chaperones (GFCs). (lancs.ac.uk)
  • Conversion of the GDP-bound proteins to the active state is catalyzed by guanine nucleotide exchange factors (GEFs) ( Van Aelst and D'Souza-Schorey, 1997 ). (biologists.org)
  • EPAC1 and EPAC2 (exchange proteins activated by cyclic AMP) are guanine nucleotide exchange factors (GEFs) that catalyze the exchange of GDP for GTP, activating Rap1 and Rap2 small GTPases. (creative-biogene.com)
  • Guanine, along with adenine and cytosine, is present in both DNA and RNA, whereas thymine is usually seen only in DNA, and uracil only in RNA. (wikipedia.org)
  • Guanine oxidizes more readily than adenine, the other purine-derivative base in DNA. (wikipedia.org)
  • 10NH3 + 2CH4 + 4C2H6 + 2H2O → 2C5H8N5O (guanine) + 25H2 A Fischer-Tropsch synthesis can also be used to form guanine, along with adenine, uracil, and thymine. (wikipedia.org)
  • What Class of Biological Molecule Do Guanine, Adenine, Cytosine and Thymine All Belong To? (reference.com)
  • Nitrogenous bases are the class of biological molecule to which guanine, adenine, cytosine and thymine belong. (reference.com)
  • Guanine and adenine belong to the purines, while thymine and cytosine are pyrimidines. (reference.com)
  • In DNA, adenine usually pairs with thymine and cytosine connects to guanine. (reference.com)
  • Adenine, guanine, cytosine and thymine are the four chemical bases found in DNA. (reference.com)
  • In a given DNA molecule, adenine always pairs with thymine, and guanine al. (reference.com)
  • Among the 4, adenine and guanine are made up of purine-derivatives. (differencebetween.net)
  • In addition, the formation of O6-(2-hydroxyethyl)guanine and 3-(2-hydroxyethyl)adenine was evaluated in rats exposed to 300 ppm ETO. (rti.org)
  • Fluorescence-linked high-performance liquid chromatography was used for O6-(2-hydroxyethyl)guanine quantitation, and immunochromatography and gas chromatography-mass spectrometry were used for 3-(2-hydroxyethyl)adenine detection. (rti.org)
  • DNA MoleculeUnder normal circumctances, it is not possible for adenine to pair up with guanine or cytosine, or for any other mismatches to occur. (enotes.com)
  • Adenine and guanine are both larger, double-ringed molecules called purines and cytosine and thymine are smaller single ringed pyrimidines. (enotes.com)
  • What does Uracil-Guanine-Adenine stand for? (thefreedictionary.com)
  • First, guanine gets deaminated to become xanthine. (wikipedia.org)
  • Guanine deaminase also known as cypin, guanase, guanine aminase, GAH, and guanine aminohydrolase is an aminohydrolase enzyme which converts guanine to xanthine. (wikipedia.org)
  • gpt xanthine-guanine phosphoribosyltransferase [Desulfovibrio vulgaris str. (nih.gov)
  • The crystal structure of the hypoxanthine-guanine-xanthine phosphoribosyltransferase (HGXPRTase) from Tritrichomonas foetus has been determined and refined against X-ray data to 1.9 A resolution. (rcsb.org)
  • In mammal organisms, guanine is transformed into xanthine under the action of the enzyme guanase. (thefreedictionary.com)
  • Indeed, analysis of in silico protein-protein interaction networks and experiments of co-immunoprecipitation indicate that PDIA1 can associate with Rho guanine dissociation inhibitor-α (RhoGDIα) in VSMC 10 . (nature.com)
  • This protein regulates gene expression by binding to the nucleotide guanine to switch off transcription. (sciencephoto.com)
  • Recombinant full length protein corresponding to Soybean Guanine nucleotide-binding protein subunit beta-like protein aa 1-325. (abcam.com)
  • A potential role for guanine nucleotide-binding protein in the regulation of endosomal proton transport. (jci.org)
  • The hSos1 protein contains a region of significant sequence similarity to CDC25, a guanine nucleotide exchange factor for Ras from yeast. (sciencemag.org)
  • A direct method has been developed for the in vitro synthesis of stable DNA-protein cross-links (DPC's) between guanine and amino acids (lysine and arginine). (biomedsearch.com)
  • The guanine nucleotide binding properties of rap1 protein purified from human neutrophils were examined using both the protein kinase A-phosphorylated and the non-phosphorylated forms of the protein. (biochemj.org)
  • These data suggest that the activation of rap in vivo may be regulated by the release of endogenous GDP, but that phosphorylation by protein kinase A does not affect guanine nucleotide binding or hydrolysis. (biochemj.org)
  • Recent data suggest that Vav functions as a guanine-nucleotide (GDP/GTP) exchange factor for members of the Rho-like small GTPase family members RhoA, Rac1, and CDC42, which regulate cytoskeletal organization and activation of the p21-activated kinase and stress-activated protein kinase/c-Jun N-terminal kinase signaling pathways ( 7 , 8 , 9 , 10 , 11 ). (jimmunol.org)
  • Rho guanine nucleotide exchange factor 11 (ARHGEF11), located on chromosome 1q21, is involved in G protein signaling and is a pathway known to play a role in both insulin secretion and action. (diabetesjournals.org)
  • The effect of activation of the alpha-subunit(s) of the stimulatory guanine-nucleotide-binding protein, Gs, on levels of this polypeptide(s) associated with the plasma membrane of L6 skeletal myoblasts was ascertained. (portlandpress.com)
  • Role of guanine nucleotide-binding protein and tyrosine kinase in platelet-activating factor activation of phospholipase C in A431 cells: proposal for dual mechanisms. (aspetjournals.org)
  • Based on these observations the involvement of PT-sensitive and -insensitive guanine nucleotide-binding protein(s) (G-protein) as well as the role of tyrosine kinase in the activation of PLC by PAF was considered further. (aspetjournals.org)
  • Guanine nucleotide-exchange factors (GEFs) are directly responsible for the activation of Rho-family GTPases in response to diverse extracellular stimuli, and ultimately regulate numerous cellular responses such as proliferation, differentiation and movement. (nih.gov)
  • Vav proto-oncogenes act as guanine exchange factors (GEFs) for the Rho/Rac GTPase family. (jneurosci.org)
  • Here we report the identification of Vav2 and Vav3 as guanine nucleotide exchange factors (GEFs) that link the EphA2 receptor to Rho family GTPase activation and angiogenesis. (asm.org)
  • Abstract: Do cytosine guanine dinucleotide (CpG) fragments induce vasoactive neuropeptide mediated fatigue-related autoimmune disorders? (prohealth.com)
  • An almost complete deficiency of the enzyme hypoxanthine guanine phosphoribosyl transferase (HPRT) is known to be the cause of the Lesch-Nyhan syndrome (1,2). (springer.com)
  • Hypoxanthine-guanine phosphoribosyltransferase (HPRT, EC 2.4.2.8) is a purine salvage enzyme that catalyses the conversion of hypoxanthine and guanine to their respective mononucleotides. (hmdb.ca)
  • Hypoxanthine-guanine phosphoribosyltransferase (HPRT) deficiency is an X-linked defect of purine metabolism. (aappublications.org)
  • Hypoxanthine-guanine phosphoribosyltransferase (HPRT, EC 2.4.3.8) is an ubiquitous, cytoplasmic, housekeeping enzyme with highest activity in the brain and testes. (aappublications.org)
  • HPRT catalyzes the transfer of the phosphoribosyl moiety of PP-ribose-P to hypoxanthine and guanine, forming inosine monophosphate and guanosine monophosphate, respectively. (aappublications.org)
  • The accepted structure of the guanine molecule was proposed in 1875, and the compound was first synthesized in 1900. (thefreedictionary.com)
  • Would the amount of cytosine and guanine be equal to each other in an RNA molecule?I need this. (enotes.com)
  • Guanine+deaminase at the US National Library of Medicine Medical Subject Headings (MeSH) Overview of all the structural information available in the PDB for UniProt: Q9Y2T3 (Human Guanine deaminase) at the PDBe-KB. (wikipedia.org)
  • We offer Guanine deaminase Lysates for use in common research applications: Western Blot. (novusbio.com)
  • Each Guanine deaminase Lysate is fully covered by our Guarantee+, to give you complete peace of mind and the support when you need it. (novusbio.com)
  • Our Guanine deaminase Lysates can be used in a variety of model species. (novusbio.com)
  • Choose from our Guanine deaminase Lysates. (novusbio.com)
  • Guanine-based purines (GBPs) have been recently proposed to be not only metabolic agents but also extracellular signaling molecules that regulate important functions in the central nervous system. (frontiersin.org)
  • Characterization of guanine and hypoxanthine phosphoribosyltransferases in Methanococcus voltae. (asm.org)
  • The core level photoemission and near edge X-ray photoabsorption spectra of guanine in the gas phase have been measured and the results interpreted with the aid of high level ab initio calculations. (lu.se)
  • The resulting absorption spectra are in good agreement with their experimental counterparts, providing useful indications on the use of PCM/TD-DFT based approaches to interpret the spectra of guanine based radicals within DNA. (dtu.dk)
  • However, it is unknown whether the presence of guanine was not simply a resultant contaminant of the reaction. (wikipedia.org)
  • Inability to recycle hypoxanthine and guanine produces a lack of feedback control of synthesis accompanied by rapid catabolism of these bases to uric acid (Fig 1) . (aappublications.org)
  • Between 1882 and 1906, Fischer determined the structure and also showed that uric acid can be converted to guanine. (wikipedia.org)
  • Biochemically, it is characterized by high uric acid concentrations in blood, high uric acid and hypoxanthine excretion in urine, and decreased activity of hypoxanthine-guanine phosphoribosyl transferase activity (HGPRT). (biomedsearch.com)
  • Gua = guanine, UA = uric acid. (aappublications.org)
  • The study deals with the primary species, ejected electrons, and guanine radicals, leading to oxidative damage, that is generated in four-stranded DNA structures (guanine quadruplexes) following photo-ionization by low-energy UV radiation. (mdpi.com)
  • G -quadruplexes are four-stranded structures formed by guanine ( G ) rich DNA/RNA strands in the presence of cations such as K + and Na + , encountered in cells. (mdpi.com)
  • In view of their biological importance and potential technological impact, characterizing the generation and fate of guanine radical cations ( G ) +● (electron holes) in G -quadruplexes is essential. (mdpi.com)
  • Guanosines with substituents at the 8-position can provide useful fluorescent probes that effectively mimic guanine residues even in highly demanding model systems such as polymorphic G-quadruplexes and duplex DNA. (uzh.ch)
  • Les brins d'ADN riches en guanine, comme ceux présents à l'extrémité des chromosomes humains, sont capables de s'associer entre eux pour former des structures G-quadruplexes, résultant de l'association de quatre guanines. (cea.fr)
  • Guanine rich DNA strands have the ability to form four-stranded structures (G-quadruplexes). (cea.fr)
  • We currently reported that Vav2, a member of the guanine nucleotide exchange factor-Vav subfamily, participates in homocysteine-induced increases in Rac1 activity and consequent activation of NADPH oxidase in rat mesangial cells. (ahajournals.org)
  • Here we show that genes encoding human PDIA1 and its two paralogs PDIA8 and PDIA2 are each flanked by genes encoding Rho guanine-dissociation inhibitors (GDI), known regulators of RhoGTPases/cytoskeleton. (nature.com)
  • Most eukaryotic telomeres contain a repeating motif with stretches of guanine residues that form a 3′-terminal overhang extending beyond the telomeric duplex region. (pnas.org)
  • The guanine nucleoside is called guanosine. (wikipedia.org)
  • The guanine-amino acid cross-links thus produced site-specifically positioned either in oligonucleotides, or in the free nucleoside tri-O-Ac-Guo were isolated by HPLC methods and identified by high resolution LC-TOF/MS and LC-MS/MS methods. (biomedsearch.com)
  • The short-range reaction involves a covalent modification of guanine by ethidium, based upon HPLC analysis of the nucleoside products and studies with ethidium derivatives. (unboundmedicine.com)
  • Allosteric hammerhead ribozymes (aptazymes) that are activated by guanine were used to control mammalian gene expression in cis and in trans. (nih.gov)
  • A gene on chromosome 9q34.1 that encodes a member of the VAV guanine nucleotide exchange factor (GEF) family of genes which is only expressed in haematopoietic cells. (thefreedictionary.com)
  • Converts guanine to guanosine monophosphate, and hypoxanthine to inosine monophosphate. (rcsb.org)
  • Energetic properties and optimized geometries of 10 radicals and their respective anions derived through hydrogen abstraction from the Watson-Crick guanine-cytosine (G-C) base pair have been studied using reliable theoretical methods. (pnas.org)
  • This method employs the combination of guanine neutral radicals, G(-H)˙, and side-chain C-centered amino acid radicals. (biomedsearch.com)
  • In the presence of a large excess of the amino acids, the hydroxyl radicals oxidize the latter to produce C-centered amino acid radicals that combine with the G(-H)˙ radicals to form the guanine-amino acid cross-linked oligonucleotide product. (biomedsearch.com)
  • In 1984, Yuasa reported a 0.00017% yield of guanine after the electrical discharge of NH 3, CH 4, C 2H 6, and 50 mL of water, followed by a subsequent acid hydrolysis. (wikipedia.org)
  • When bonded with other compounds, guanine is responsible for intracellular signaling networks, which is important for communication within the cell. (differencebetween.net)
  • 3. Guanine, with a chemical formula of C5H5N5O, has a role in intracellular signaling networks. (differencebetween.net)
  • Partial hypoxanthine-guanine phosphoribosyl transferase deficiency without elevated urinary hypoxanthine excretion. (biomedsearch.com)
  • Partial hypoxanthine-guanine phosphoribosyl transferase (HGPRT) deficiency, also known as the Kelley-Seegmiller syndrome, can give rise to a wide range of neurological symptoms, and renal insufficiency. (biomedsearch.com)
  • Guanine has two tautomeric forms, the major keto form (see figures) and rare enol form. (wikipedia.org)
  • With the formula C5H5N5O, guanine is a derivative of purine, consisting of a fused pyrimidine-imidazole ring system with conjugated double bonds. (wikipedia.org)
  • On the other hand, guanine is also a purine-derivative. (differencebetween.net)
  • It has been shown that the G-rich overhang can adopt a variety of unusual DNA structures ( 4 ), of which guanine-quadruplex DNA and t-loops are stable in vitro under physiological conditions ( 5 - 8 ). (pnas.org)
  • Parallel-stranded as well as antiparallel-stranded guanine-quadruplex structures have been biophysically and structurally analyzed in detail with synthetic oligonucleotides ( 6 - 11 ). (pnas.org)
  • Mammalian cells overexpressing full-length hSos1 had increased guanine nucleotide exchange activity. (sciencemag.org)
  • Cytosine guanine dinucleotide (CpG) fragments are potently immunogenic DNA fragments which serve as friend or foe recognition systems between bacterial (hypomethylated) and mammalian (methylated) DNA and are being assessed for suitability for use in human vaccines as adjuvants. (prohealth.com)
  • Mammalian telomeres consist of triple guanine repeats and are subject to oxidative guanine damage. (prolekare.cz)
  • This reactivity is not consistent with oxidation of guanine by either electron transfer or singlet oxygen as shown by comparison with reactions of a rhodium intercalator and methylene blue, respectively. (unboundmedicine.com)
  • Of the scFvs selected, one (Sty3) had an affinity of K d = 125 pM for the parallel-stranded guanine-quadruplex and could discriminate with at least 1,000-fold specificity between parallel or antiparallel quadruplex conformations formed by the same sequence motif. (pnas.org)
  • 100 guanine nucleotide exchange factors, Vav subfamily exhibits the high specificity to Rac-mediated NADPH oxidase activation. (ahajournals.org)
  • Peroxynitrite induces DNA base damage predominantly at guanine (G) and 8-oxoguanine (8-oxoG) nucleobases via oxidation reactions. (hmdb.ca)
  • The long-range reaction is entirely consistent with oxidation of guanine by DNA-mediated electron transfer. (unboundmedicine.com)
  • Your search returned 13 alsin Rho guanine nucleotide exchange factor ELISA ELISA Kit across 2 suppliers. (biocompare.com)
  • 6 On cell activation, GDP-bound Rac under resting condition may be converted into GTP-Rac through the action of a guanine nucleotide exchange factor. (ahajournals.org)
  • Thus hSos1 is a guanine nucleotide exchange factor for Ras. (sciencemag.org)
  • These results provide the first genetic evidence on the role of the guanine exchange factor Vav in immune responses to viral infections and antigenic challenge in vivo, and suggest that Vav adjusts the threshold for Ag receptor-mediated B cell activation depending on the nature of the Ag. (jimmunol.org)
  • Genotyping of multiple single nucleotide polymorphisms (SNPs) within the region of linkage as part of our linkage disequilibrium (LD) mapping studies in the Amish pointed to a region containing Rho guanine nucleotide exchange factor 11 (ARHGEF11). (diabetesjournals.org)
  • Arhgef4 acts as guanine nucleotide exchange factor (GEF) for RHOA, RAC1 and CDC42 GTPases. (antikoerper-online.de)
  • 2020), The Rho guanine nucleotide exchange factor Trio. (xenbase.org)
  • The Rho guanine nucleotide exchange factor Trio is required for neural crest cell migration and interacts with Dishevelled . (xenbase.org)
  • The Rho guanine exchange factor (GEF) Trio is especially well suited to relay signals, as it features distinct catalytic domains to activate Rho GTPases. (xenbase.org)
  • Mss4 also acts as a relatively inefficient guanine nucleotide exchange factor (GEF). (lancs.ac.uk)
  • We perform experiments that show that simple guanine repeats 13 bp (base pairs) in length or longer ( G 13+ ) increase the substitution rate 4- to 18-fold in the downstream DNA sequence, and this correlates with DNA replication timing ( R = 0.89). (sciencemag.org)
  • Facial treatments using the droppings, or guano, from Japanese nightingales have been used in Japan and elsewhere, because the guanine in the droppings makes the skin look paler. (wikipedia.org)
  • The first isolation of guanine was reported in 1844 from the excreta of sea birds, known as guano, which was used as a source of fertilizer. (hmdb.ca)
  • While no DNA reaction is observed upon excitation into the visible absorption band of ethidium, higher-energy irradiation (313-340 nm) leads both to direct strand cleavage at the 5'-G of 5'-GG-3' doublets and to piperidine-sensitive lesions at guanine. (unboundmedicine.com)
  • Oxidative guanine lesions were increased in telomeres in Ogg1 −/− mice with aging and primary MEFs cultivated in 20% oxygen. (prolekare.cz)
  • Furthermore, oxidative guanine lesions persisted at high level in Ogg1 −/− MEFs after acute exposure to hydrogen peroxide, while they rapidly returned to basal level in wild-type MEFs. (prolekare.cz)
  • Heating an equimolar gas mixture of CO, H2, and NH3 to 700 °C for 15 to 24 minutes, followed by quick cooling and then sustained reheating to 100 to 200 °C for 16 to 44 hours with an alumina catalyst, yielded guanine and uracil: 10CO + H2 + 10NH3 → 2C5H8N5O (guanine) + 8H2O Another possible abiotic route was explored by quenching a 90% N2-10%CO-H2O gas mixture high-temperature plasma. (wikipedia.org)
  • Stimulation of Ca2+-independent catecholamine secretion from digitonin-permeabilized bovine adrenal chromaffin cells by guanine nucleotide analogues. (portlandpress.com)