An essential amino acid. It is often added to animal feed.

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.

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.

The parts of a macromolecule that directly participate in its specific combination with another molecule.

Genetically engineered MUTAGENESIS at a specific site in the DNA molecule that introduces a base substitution, or an insertion or deletion.

Models used experimentally or theoretically to study molecular shape, electronic properties, or interactions; includes analogous molecules, computer-generated graphics, and mechanical structures.

Formation of an acetyl derivative. (Stedman, 25th ed)

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.

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).

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.

Organic compounds that generally contain an amino (-NH2) and a carboxyl (-COOH) group. Twenty alpha-amino acids are the subunits which are polymerized to form proteins.

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 rate dynamics in chemical or physical systems.

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)

The degree of similarity between sequences of amino acids. This information is useful for the analyzing genetic relatedness of proteins and species.

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.

Methylmaleic anhydrides.

Small chromosomal proteins (approx 12-20 kD) possessing an open, unfolded structure and attached to the DNA in cell nuclei by ionic linkages. Classification into the various types (designated histone I, histone II, etc.) is based on the relative amounts of arginine and lysine in each.

The naturally occurring or experimentally induced replacement of one or more AMINO ACIDS in a protein with another. If a functionally equivalent amino acid is substituted, the protein may retain wild-type activity. Substitution may also diminish, enhance, or eliminate protein function. Experimentally induced substitution is often used to study enzyme activities and binding site properties.

The sequence of PURINES and PYRIMIDINES in nucleic acids and polynucleotides. It is also called nucleotide sequence.

Partial proteins formed by partial hydrolysis of complete proteins or generated through PROTEIN ENGINEERING techniques.

The level of protein structure in which regular hydrogen-bond interactions within contiguous stretches of polypeptide chain give rise to alpha helices, beta strands (which align to form beta sheets) or other types of coils. This is the first folding level of protein conformation.

Any of various enzymatically catalyzed post-translational modifications of PEPTIDES or PROTEINS in the cell of origin. These modifications include carboxylation; HYDROXYLATION; ACETYLATION; PHOSPHORYLATION; METHYLATION; GLYCOSYLATION; ubiquitination; oxidation; proteolysis; and crosslinking and result in changes in molecular weight and electrophoretic motility.

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.

This is the active form of VITAMIN B 6 serving as a coenzyme for synthesis of amino acids, neurotransmitters (serotonin, norepinephrine), sphingolipids, aminolevulinic acid. During transamination of amino acids, pyridoxal phosphate is transiently converted into pyridoxamine phosphate (PYRIDOXAMINE).

Proteins prepared by recombinant DNA technology.

A characteristic feature of enzyme activity in relation to the kind of substrate on which the enzyme or catalytic molecule reacts.

An essential amino acid that is physiologically active in the L-form.

Members of the class of compounds composed of AMINO ACIDS joined together by peptide bonds between adjacent amino acids into linear, branched or cyclical structures. OLIGOPEPTIDES are composed of approximately 2-12 amino acids. Polypeptides are composed of approximately 13 or more amino acids. PROTEINS are linear polypeptides that are normally synthesized on RIBOSOMES.

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.

A thiol-containing non-essential amino acid that is oxidized to form CYSTINE.

The act of ligating UBIQUITINS to PROTEINS to form ubiquitin-protein ligase complexes to label proteins for transport to the PROTEASOME ENDOPEPTIDASE COMPLEX where proteolysis occurs.

An essential amino acid that is required for the production of HISTAMINE.

A highly conserved 76-amino acid peptide universally found in eukaryotic cells that functions as a marker for intracellular PROTEIN TRANSPORT and degradation. Ubiquitin becomes activated through a series of complicated steps and forms an isopeptide bond to lysine residues of specific proteins within the cell. These "ubiquitinated" proteins can be recognized and degraded by proteosomes or be transported to specific compartments within the cell.

The study of crystal structure using X-RAY DIFFRACTION techniques. (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)

The facilitation of a chemical reaction by material (catalyst) that is not consumed by the reaction.

A serine endopeptidase that is formed from TRYPSINOGEN in the pancreas. It is converted into its active form by ENTEROPEPTIDASE in the small intestine. It catalyzes hydrolysis of the carboxyl group of either arginine or lysine. EC 3.4.21.4.

A 1.5-kDa small ubiquitin-related modifier protein that can covalently bind via an isopeptide link to a number of cellular proteins. It may play a role in intracellular protein transport and a number of other cellular processes.

A sequence of amino acids in a polypeptide or of nucleotides in DNA or RNA that is similar across multiple species. A known set of conserved sequences is represented by a CONSENSUS SEQUENCE. AMINO ACID MOTIFS are often composed of conserved sequences.

The normality of a solution with respect to HYDROGEN ions; H+. It is related to acidity measurements in most cases by pH = log 1/2[1/(H+)], where (H+) is the hydrogen ion concentration in gram equivalents per liter of solution. (McGraw-Hill Dictionary of Scientific and Technical Terms, 6th ed)

Established cell cultures that have the potential to propagate indefinitely.

Esters of the hypothetical imidic acids. They react with amines or amino acids to form amidines and are therefore used to modify protein structures and as cross-linking agents.

Liquid chromatographic techniques which feature high inlet pressures, high sensitivity, and high speed.

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.

The region of an enzyme that interacts with its substrate to cause the enzymatic reaction.

A class of inorganic or organic compounds that contain the borohydride (BH4-) anion.

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).

An analytical method used in determining the identity of a chemical based on its mass using mass analyzers/mass spectrometers.

Commonly observed structural components of proteins formed by simple combinations of adjacent secondary structures. A commonly observed structure may be composed of a CONSERVED SEQUENCE which can be represented by a CONSENSUS SEQUENCE.

Compounds used extensively as acetylation, oxidation and dehydrating agents and in the modification of proteins and enzymes.

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.

Electrophoresis in which a polyacrylamide gel is used as the diffusion medium.

A non-essential amino acid that occurs in high levels in its free state in plasma. It is produced from pyruvate by transamination. It is involved in sugar and acid metabolism, increases IMMUNITY, and provides energy for muscle tissue, BRAIN, and the CENTRAL NERVOUS SYSTEM.

A family of histone acetyltransferases that is structurally-related to CREB-BINDING PROTEIN and to E1A-ASSOCIATED P300 PROTEIN. They function as transcriptional coactivators by bridging between DNA-binding TRANSCRIPTION FACTORS and the basal transcription machinery. They also modify transcription factors and CHROMATIN through ACETYLATION.

A change from planar to elliptic polarization when an initially plane-polarized light wave traverses an optically active medium. (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)

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.

Enzymes that catalyze acyl group transfer from ACETYL-CoA to HISTONES forming CoA and acetyl-histones.

Proteins found in any species of bacterium.

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.

Process of generating a genetic MUTATION. It may occur spontaneously or be induced by MUTAGENS.

A type of POST-TRANSLATIONAL PROTEIN MODIFICATION by SMALL UBIQUITIN-RELATED MODIFIER PROTEINS (also known as SUMO proteins).

A basic science concerned with the composition, structure, and properties of matter; and the reactions that occur between substances and the associated energy exchange.

The composition, conformation, and properties of atoms and molecules, and their reaction and interaction processes.

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.

Chemical compounds derived from acids by the elimination of a molecule of water.

A class of structurally related proteins of 12-20 kDa in size. They covalently modify specific proteins in a manner analogous to UBIQUITIN.

Enzymes catalyzing the transfer of an acetyl group, usually from acetyl coenzyme A, to another compound. EC 2.3.1.

A class of enzymes that form a thioester bond to UBIQUITIN with the assistance of UBIQUITIN-ACTIVATING ENZYMES. They transfer ubiquitin to the LYSINE of a substrate protein with the assistance of UBIQUITIN-PROTEIN LIGASES.

Drugs and their metabolites which are found in the edible tissues and milk of animals after their medication with specific drugs. This term can also apply to drugs found in adipose tissue of humans after drug treatment.

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 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).

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.

The process of cleaving a chemical compound by the addition of a molecule of water.

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 catalyze the methylation of amino acids after their incorporation into a polypeptide chain. S-Adenosyl-L-methionine acts as the methylating agent. EC 2.1.1.

A family of proteins that are structurally-related to Ubiquitin. Ubiquitins and ubiquitin-like proteins participate in diverse cellular functions, such as protein degradation and HEAT-SHOCK RESPONSE, by conjugation to other proteins.

An essential amino acid that is necessary for normal growth in infants and for NITROGEN balance in adults. It is a precursor of INDOLE ALKALOIDS in plants. It is a precursor of SEROTONIN (hence its use as an antidepressant and sleep aid). It can be a precursor to NIACIN, albeit inefficiently, in mammals.

Cyanogen bromide (CNBr). A compound used in molecular biology to digest some proteins and as a coupling reagent for phosphoroamidate or pyrophosphate internucleotide bonds in DNA duplexes.

A metabolite in the principal biochemical pathway of lysine. It antagonizes neuroexcitatory activity modulated by the glutamate receptor, N-METHYL-D-ASPARTATE; (NMDA).

The introduction of a phosphoryl group into a compound through the formation of an ester bond between the compound and a phosphorus moiety.

An oligomer formed from the repetitive linking of the C-terminal glycine of one UBIQUITIN molecule via an isopeptide bond to a lysine residue on a second ubiquitin molecule. It is structurally distinct from UBIQUITIN C, which is a single protein containing a tandemly arrayed ubiquitin peptide sequence.

Theoretical representations that simulate the behavior or activity of chemical processes or phenomena; includes the use of mathematical equations, computers, and other electronic equipment.

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.

Analysis of PEPTIDES that are generated from the digestion or fragmentation of a protein or mixture of PROTEINS, by ELECTROPHORESIS; CHROMATOGRAPHY; or MASS SPECTROMETRY. The resulting peptide fingerprints are analyzed for a variety of purposes including the identification of the proteins in a sample, GENETIC POLYMORPHISMS, patterns of gene expression, and patterns diagnostic for diseases.

A non-essential amino acid occurring in natural form as the L-isomer. It is synthesized from GLYCINE or THREONINE. It is involved in the biosynthesis of PURINES; PYRIMIDINES; and other amino acids.

Amino acids with side chains that are positively charged at physiological pH.

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.

The sum of the weight of all the atoms in a molecule.

Measurement of the intensity and quality of fluorescence.

Pesticides or their breakdown products remaining in the environment following their normal use or accidental contamination.

A non-essential amino acid. In animals it is synthesized from PHENYLALANINE. It is also the precursor of EPINEPHRINE; THYROID HORMONES; and melanin.

'Homoarginine' is a non-proteinogenic amino acid, meaning it is not used in the formation of proteins, and is primarily found in small quantities in certain foods and synthesized in the human body from the amino acid lysine.

An essential amino acid occurring naturally in the L-form, which is the active form. It is found in eggs, milk, gelatin, and other proteins.

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).)

Processes involved in the formation of TERTIARY PROTEIN STRUCTURE.

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.

The accumulation of an electric charge on a object

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.

Precursor of plasmin (FIBRINOLYSIN). It is a single-chain beta-globulin of molecular weight 80-90,000 found mostly in association with fibrinogen in plasma; plasminogen activators change it to fibrinolysin. It is used in wound debriding and has been investigated as a thrombolytic agent.

Proteins obtained from ESCHERICHIA COLI.

A diverse class of enzymes that interact with UBIQUITIN-CONJUGATING ENZYMES and ubiquitination-specific protein substrates. Each member of this enzyme group has its own distinct specificity for a substrate and ubiquitin-conjugating enzyme. Ubiquitin-protein ligases exist as both monomeric proteins multiprotein complexes.

One of the non-essential amino acids commonly occurring in the L-form. It is found in animals and plants, especially in sugar cane and sugar beets. It may be a neurotransmitter.

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.

Chromatography on non-ionic gels without regard to the mechanism of solute discrimination.

A subclass of anhydrides with the general structure of dihydrofurandione. They can be substituted on any carbon atom. They modify and inhibit proteins and enzymes and are used in the acylation of amino- and hydroxyl groups.

Preservative for wines, soft drinks, and fruit juices and a gentle esterifying agent.

Any of various animals that constitute the family Suidae and comprise stout-bodied, short-legged omnivorous mammals with thick skin, usually covered with coarse bristles, a rather long mobile snout, and small tail. Included are the genera Babyrousa, Phacochoerus (wart hogs), and Sus, the latter containing the domestic pig (see SUS SCROFA).

A reagent that is used to neutralize peptide terminal amino groups.

Short sequences (generally about 10 base pairs) of DNA that are complementary to sequences of messenger RNA and allow reverse transcriptases to start copying the adjacent sequences of mRNA. Primers are used extensively in genetic and molecular biology techniques.

A molecule that binds to another molecule, used especially to refer to a small molecule that binds specifically to a larger molecule, e.g., an antigen binding to an antibody, a hormone or neurotransmitter binding to a receptor, or a substrate or allosteric effector binding to an enzyme. Ligands are also molecules that donate or accept a pair of electrons to form a coordinate covalent bond with the central metal atom of a coordination complex. (From Dorland, 27th ed)

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.

The process by which two molecules of the same chemical composition form a condensation product or polymer.

Proteins which bind to DNA. The family includes proteins which bind to both double- and single-stranded DNA and also includes specific DNA binding proteins in serum which can be used as markers for malignant diseases.

Transport proteins that carry specific substances in the blood or across cell membranes.

Protein modules with conserved ligand-binding surfaces which mediate specific interaction functions in SIGNAL TRANSDUCTION PATHWAYS and the specific BINDING SITES of their cognate protein LIGANDS.

Transglutaminases catalyze cross-linking of proteins at a GLUTAMINE in one chain with LYSINE in another chain. They include keratinocyte transglutaminase (TGM1 or TGK), tissue transglutaminase (TGM2 or TGC), plasma transglutaminase involved with coagulation (FACTOR XIII and FACTOR XIIIa), hair follicle transglutaminase, and prostate transglutaminase. Although structures differ, they share an active site (YGQCW) and strict CALCIUM dependence.

The lipid- and protein-containing, selectively permeable membrane that surrounds the cytoplasm in prokaryotic and eukaryotic cells.

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.

A mass spectrometric technique that is used for the analysis of large biomolecules. Analyte molecules are embedded in an excess matrix of small organic molecules that show a high resonant absorption at the laser wavelength used. The matrix absorbs the laser energy, thus inducing a soft disintegration of the sample-matrix mixture into free (gas phase) matrix and analyte molecules and molecular ions. In general, only molecular ions of the analyte molecules are produced, and almost no fragmentation occurs. This makes the method well suited for molecular weight determinations and mixture analysis.

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 non-essential amino acid present abundantly throughout the body and is involved in many metabolic processes. It is synthesized from GLUTAMIC ACID and AMMONIA. It is the principal carrier of NITROGEN in the body and is an important energy source for many cells.

Determination of the spectra of ultraviolet absorption by specific molecules in gases or liquids, for example Cl2, SO2, NO2, CS2, ozone, mercury vapor, and various unsaturated compounds. (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)

Imides are organic compounds characterized by the presence of a functional group with the structure R-C(=O)-N-R', where R and R' are organic radicals, often found in pharmaceuticals, dyes, and as intermediates in chemical synthesis.

Deacetylases that remove N-acetyl groups from amino side chains of the amino acids of HISTONES. The enzyme family can be divided into at least three structurally-defined subclasses. Class I and class II deacetylases utilize a zinc-dependent mechanism. The sirtuin histone deacetylases belong to class III and are NAD-dependent enzymes.

A rigorously mathematical analysis of energy relationships (heat, work, temperature, and equilibrium). It describes systems whose states are determined by thermal parameters, such as temperature, in addition to mechanical and electromagnetic parameters. (From Hawley's Condensed Chemical Dictionary, 12th ed)

A mixed-function oxygenase that catalyzes the hydroxylation of peptidyllysine, usually in protocollagen, to peptidylhydroxylysine. The enzyme utilizes molecular oxygen with concomitant oxidative decarboxylation of the cosubstrate 2-oxoglutarate to succinate. EC 1.14.11.4.

A reagent that is highly selective for the modification of arginyl residues. It is used to selectively inhibit various enzymes and acts as an energy transfer inhibitor in photophosphorylation.

The biosynthesis of RNA carried out on a template of DNA. The biosynthesis of DNA from an RNA template is called REVERSE TRANSCRIPTION.

The species Oryctolagus cuniculus, in the family Leporidae, order LAGOMORPHA. Rabbits are born in burrows, furless, and with eyes and ears closed. In contrast with HARES, rabbits have 22 chromosome pairs.

Incorporation of biotinyl groups into molecules.

NMR spectroscopy on small- to medium-size biological macromolecules. This is often used for structural investigation of proteins and nucleic acids, and often involves more than one isotope.

The chemical or biochemical addition of carbohydrate or glycosyl groups to other chemicals, especially peptides or proteins. Glycosyl transferases are used in this biochemical reaction.

The thermodynamic interaction between a substance and WATER.

The extent to which an enzyme retains its structural conformation or its activity when subjected to storage, isolation, and purification or various other physical or chemical manipulations, including proteolytic enzymes and heat.

A subclass of IMIDES with the general structure of pyrrolidinedione. They are prepared by the distillation of ammonium succinate. They are sweet-tasting compounds that are used as chemical intermediates and plant growth stimulants.

Endogenous substances, usually proteins, which are effective in the initiation, stimulation, or termination of the genetic transcription process.

Chemical groups containing the covalent disulfide bonds -S-S-. The sulfur atoms can be bound to inorganic or organic moieties.

The ability of a protein to retain its structural conformation or its activity when subjected to physical or chemical manipulations.

A mutation in which a codon is mutated to one directing the incorporation of a different amino acid. This substitution may result in an inactive or unstable product. (From A Dictionary of Genetics, King & Stansfield, 5th ed)

The characteristic 3-dimensional shape and arrangement of multimeric proteins (aggregates of more than one polypeptide chain).

A serine endopeptidase secreted by the pancreas as its zymogen, CHYMOTRYPSINOGEN and carried in the pancreatic juice to the duodenum where it is activated by TRYPSIN. It selectively cleaves aromatic amino acids on the carboxyl side.

A water-soluble, enzyme co-factor present in minute amounts in every living cell. It occurs mainly bound to proteins or polypeptides and is abundant in liver, kidney, pancreas, yeast, and milk.

Peptides composed of between two and twelve amino acids.

A cell line generated from human embryonic kidney cells that were transformed with human adenovirus type 5.

The material of CHROMOSOMES. It is a complex of DNA; HISTONES; and nonhistone proteins (CHROMOSOMAL PROTEINS, NON-HISTONE) found within the nucleus of a cell.

Enzymes that catalyse the removal of methyl groups from LYSINE or ARGININE residues found on HISTONES. Many histone demethylases generally function through an oxidoreductive mechanism.

A subclass of enzymes of the transferase class that catalyze the transfer of a methyl group from one compound to another. (Dorland, 28th ed) EC 2.1.1.

Single-stranded complementary DNA synthesized from an RNA template by the action of RNA-dependent DNA polymerase. cDNA (i.e., complementary DNA, not circular DNA, not C-DNA) is used in a variety of molecular cloning experiments as well as serving as a specific hybridization probe.

A large multisubunit complex that plays an important role in the degradation of most of the cytosolic and nuclear proteins in eukaryotic cells. It contains a 700-kDa catalytic sub-complex and two 700-kDa regulatory sub-complexes. The complex digests ubiquitinated proteins and protein activated via ornithine decarboxylase antizyme.

A subfamily in the family MURIDAE, comprising the hamsters. Four of the more common genera are Cricetus, CRICETULUS; MESOCRICETUS; and PHODOPUS.

An adenine nucleotide containing three phosphate groups esterified to the sugar moiety. In addition to its crucial roles in metabolism adenosine triphosphate is a neurotransmitter.

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.

Analogs of those substrates or compounds which bind naturally at the active sites of proteins, enzymes, antibodies, steroids, or physiological receptors. These analogs form a stable covalent bond at the binding site, thereby acting as inhibitors of the proteins or steroids.

A hydroxylated derivative of the amino acid LYSINE that is present in certain collagens.

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 non-essential amino acid that is synthesized from GLUTAMIC ACID. It is an essential component of COLLAGEN and is important for proper functioning of joints and tendons.

The assembly of the QUATERNARY PROTEIN STRUCTURE of multimeric proteins (MULTIPROTEIN COMPLEXES) from their composite PROTEIN SUBUNITS.

Proteins found in the nucleus of a cell. Do not confuse with NUCLEOPROTEINS which are proteins conjugated with nucleic acids, that are not necessarily present in the nucleus.

A non-essential amino acid. It is found primarily in gelatin and silk fibroin and used therapeutically as a nutrient. It is also a fast inhibitory neurotransmitter.

Condensation products of aromatic amines and aldehydes forming azomethines substituted on the N atom, containing the general formula R-N:CHR. (From Grant & Hackh's Chemical Dictionary, 5th ed)

A family of histone demethylases that share a conserved Jumonji C domain. The enzymes function via an iron-dependent dioxygenase mechanism that couples the conversion of 2-oxoglutarate to succinate to the hydroxylation of N-methyl groups.

An enzyme that catalyzes the methylation of the epsilon-amino group of lysine residues in proteins to yield epsilon mono-, di-, and trimethyllysine. EC 2.1.1.43.

An essential aromatic amino acid that is a precursor of MELANIN; DOPAMINE; noradrenalin (NOREPINEPHRINE), and THYROXINE.

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.

A reagent that forms fluorescent conjugation products with primary amines. It is used for the detection of many biogenic amines, peptides, and proteins in nanogram quantities in body fluids.

Electrophoresis in which paper is used as the diffusion medium. This technique is confined almost entirely to separations of small molecules such as amino acids, peptides, and nucleotides, and relatively high voltages are nearly always used.

Organic compounds containing a carbonyl group in the form -CHO.

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.

A sulfur-containing essential L-amino acid that is important in many body functions.

A subclass of PEPTIDE HYDROLASES that catalyze the internal cleavage of PEPTIDES or PROTEINS.

Identification of proteins or peptides that have been electrophoretically separated by blot transferring from the electrophoresis gel to strips of nitrocellulose paper, followed by labeling with antibody probes.

Proteins which maintain the transcriptional quiescence of specific GENES or OPERONS. Classical repressor proteins are DNA-binding proteins that are normally bound to the OPERATOR REGION of an operon, or the ENHANCER SEQUENCES of a gene until a signal occurs that causes their release.

Deletion of sequences of nucleic acids from the genetic material of an individual.

Common name for the species Gallus gallus, the domestic fowl, in the family Phasianidae, order GALLIFORMES. It is descended from the red jungle fowl of SOUTHEAST ASIA.

A mass spectrometry technique used for analysis of nonvolatile compounds such as proteins and macromolecules. The technique involves preparing electrically charged droplets from analyte molecules dissolved in solvent. The electrically charged droplets enter a vacuum chamber where the solvent is evaporated. Evaporation of solvent reduces the droplet size, thereby increasing the coulombic repulsion within the droplet. As the charged droplets get smaller, the excess charge within them causes them to disintegrate and release analyte molecules. The volatilized analyte molecules are then analyzed by mass spectrometry.

A species of CERCOPITHECUS containing three subspecies: C. tantalus, C. pygerythrus, and C. sabeus. They are found in the forests and savannah of Africa. The African green monkey (C. pygerythrus) is the natural host of SIMIAN IMMUNODEFICIENCY VIRUS and is used in AIDS research.

Biochemical identification of mutational changes in a nucleotide sequence.

The addition of an organic acid radical into a molecule.

A non-essential amino acid naturally occurring in the L-form. Glutamic acid is the most common excitatory neurotransmitter in the CENTRAL NERVOUS SYSTEM.

A process that includes the determination of AMINO ACID SEQUENCE of a protein (or peptide, oligopeptide or peptide fragment) and the information analysis of the sequence.

Separation technique in which the stationary phase consists of ion exchange resins. The resins contain loosely held small ions that easily exchange places with other small ions of like charge present in solutions washed over the resins.

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.

The part of a cell that contains the CYTOSOL and small structures excluding the CELL NUCLEUS; MITOCHONDRIA; and large VACUOLES. (Glick, Glossary of Biochemistry and Molecular Biology, 1990)

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.

Amine oxidoreductases that use either NAD+ (EC 1.5.1.7) or NADP+ (EC 1.5.1.8) as an acceptor to form L-LYSINE or NAD+ (EC 1.5.1.9) or NADP+ (EC 1.5.1.10) as an acceptor to form L-GLUTAMATE. Deficiency of this enzyme causes HYPERLYSINEMIAS.

A colorless inorganic compound (HONH2) used in organic synthesis and as a reducing agent, due to its ability to donate nitric oxide.

The sequential correspondence of nucleotides in one nucleic acid molecule with those of another nucleic acid molecule. Sequence homology is an indication of the genetic relatedness of different organisms and gene function.

A ZINC-dependent carboxypeptidase primary found in the DIGESTIVE SYSTEM. The enzyme catalyzes the preferential cleavage of a C-terminal peptidyl-L-lysine or arginine. It was formerly classified as EC 3.4.2.2 and EC 3.4.12.3.

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.

Enzymes that act at a free C-terminus of a polypeptide to liberate a single amino acid residue.

Within a eukaryotic cell, a membrane-limited body which contains chromosomes and one or more nucleoli (CELL NUCLEOLUS). The nuclear membrane consists of a double unit-type membrane which is perforated by a number of pores; the outermost membrane is continuous with the ENDOPLASMIC RETICULUM. A cell may contain more than one nucleus. (From Singleton & Sainsbury, Dictionary of Microbiology and Molecular Biology, 2d ed)

A chromatographic technique that utilizes the ability of biological molecules to bind to certain ligands specifically and reversibly. It is used in protein biochemistry. (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)

Single chains of amino acids that are the units of multimeric PROTEINS. Multimeric proteins can be composed of identical or non-identical subunits. One or more monomeric subunits may compose a protomer which itself is a subunit structure of a larger assembly.

The characteristic three-dimensional shape of a molecule.

A product of the lysis of plasminogen (profibrinolysin) by PLASMINOGEN activators. It is composed of two polypeptide chains, light (B) and heavy (A), with a molecular weight of 75,000. It is the major proteolytic enzyme involved in blood clot retraction or the lysis of fibrin and quickly inactivated by antiplasmins.

The facilitation of biochemical reactions with the aid of naturally occurring catalysts such as ENZYMES.

Disruption of the non-covalent bonds and/or disulfide bonds responsible for maintaining the three-dimensional shape and activity of the native protein.

CELL LINE derived from the ovary of the Chinese hamster, Cricetulus griseus (CRICETULUS). The species is a favorite for cytogenetic studies because of its small chromosome number. The cell line has provided model systems for the study of genetic alterations in cultured mammalian cells.

A method of gel filtration chromatography using agarose, the non-ionic component of agar, for the separation of compounds with molecular weights up to several million.

A non-essential amino acid that is involved in the metabolic control of cell functions in nerve and brain tissue. It is biosynthesized from ASPARTIC ACID and AMMONIA by asparagine synthetase. (From Concise Encyclopedia Biochemistry and Molecular Biology, 3rd ed)

Protein precursors, also known as proproteins or prohormones, are inactive forms of proteins that undergo post-translational modification, such as cleavage, to produce the active functional protein or peptide hormone.

Proteins covalently modified with UBIQUITINS or UBIQUITIN-LIKE PROTEINS.