Amino Acid Sequence: 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.Neurotoxins: Toxic substances from microorganisms, plants or animals that interfere with the functions of the nervous system. Most venoms contain neurotoxic substances. Myotoxins are included in this concept.Amino Acids: 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.Molecular Sequence Data: 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.Sequence Homology, Amino Acid: The degree of similarity between sequences of amino acids. This information is useful for the analyzing genetic relatedness of proteins and species.Amino Acid Substitution: 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.Base Sequence: The sequence of PURINES and PYRIMIDINES in nucleic acids and polynucleotides. It is also called nucleotide sequence.Cloning, Molecular: 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.Botulinum Toxins: Toxic proteins produced from the species CLOSTRIDIUM BOTULINUM. The toxins are synthesized as a single peptide chain which is processed into a mature protein consisting of a heavy chain and light chain joined via a disulfide bond. The botulinum toxin light chain is a zinc-dependent protease which is released from the heavy chain upon ENDOCYTOSIS into PRESYNAPTIC NERVE ENDINGS. Once inside the cell the botulinum toxin light chain cleaves specific SNARE proteins which are essential for secretion of ACETYLCHOLINE by SYNAPTIC VESICLES. This inhibition of acetylcholine release results in muscular PARALYSIS.Mutagenesis, Site-Directed: Genetically engineered MUTAGENESIS at a specific site in the DNA molecule that introduces a base substitution, or an insertion or deletion.Binding Sites: The parts of a macromolecule that directly participate in its specific combination with another molecule.Models, Molecular: Models used experimentally or theoretically to study molecular shape, electronic properties, or interactions; includes analogous molecules, computer-generated graphics, and mechanical structures.Mutation: 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.Sequence Alignment: 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.Protein Conformation: 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).Structure-Activity Relationship: 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.Escherichia coli: 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.Protein Structure, Tertiary: 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.Recombinant Proteins: Proteins prepared by recombinant DNA technology.Kinetics: The rate dynamics in chemical or physical systems.Peptide Fragments: Partial proteins formed by partial hydrolysis of complete proteins or generated through PROTEIN ENGINEERING techniques.Protein Binding: 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.Substrate Specificity: A characteristic feature of enzyme activity in relation to the kind of substrate on which the enzyme or catalytic molecule reacts.Protein Structure, Secondary: 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.DNA, Complementary: 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.Peptides: 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.Amino Acid Motifs: 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.Sequence Homology, Nucleic Acid: 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.Tetanus Toxin: Protein synthesized by CLOSTRIDIUM TETANI as a single chain of ~150 kDa with 35% sequence identity to BOTULINUM TOXIN that is cleaved to a light and a heavy chain that are linked by a single disulfide bond. Tetanolysin is the hemolytic and tetanospasmin is the neurotoxic principle. The toxin causes disruption of the inhibitory mechanisms of the CNS, thus permitting uncontrolled nervous activity, leading to fatal CONVULSIONS.Elapid Venoms: Venoms from snakes of the family Elapidae, including cobras, kraits, mambas, coral, tiger, and Australian snakes. The venoms contain polypeptide toxins of various kinds, cytolytic, hemolytic, and neurotoxic factors, but fewer enzymes than viper or crotalid venoms. Many of the toxins have been characterized.Bacterial Proteins: Proteins found in any species of bacterium.DNA: 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).Cell Line: Established cell cultures that have the potential to propagate indefinitely.Recombinant Fusion Proteins: 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.Conserved Sequence: 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.Molecular Weight: The sum of the weight of all the atoms in a molecule.Cobra Neurotoxin Proteins: Toxins, contained in cobra (Naja) venom that block cholinergic receptors; two specific proteins have been described, the small (short, Type I) and the large (long, Type II) which also exist in other Elapid venoms.Point Mutation: 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.Botulinum Toxins, Type A: A serotype of botulinum toxins that has specificity for cleavage of SYNAPTOSOMAL-ASSOCIATED PROTEIN 25.Alanine: 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.Restriction Mapping: Use of restriction endonucleases to analyze and generate a physical map of genomes, genes, or other segments of DNA.Electrophoresis, Polyacrylamide Gel: Electrophoresis in which a polyacrylamide gel is used as the diffusion medium.Amino Acids, Essential: Amino acids that are not synthesized by the human body in amounts sufficient to carry out physiological functions. They are obtained from dietary foodstuffs.Clostridium botulinum: A species of anaerobic, gram-positive, rod-shaped bacteria in the family Clostridiaceae that produces proteins with characteristic neurotoxicity. It is the etiologic agent of BOTULISM in humans, wild fowl, HORSES; and CATTLE. Seven subtypes (sometimes called antigenic types, or strains) exist, each producing a different botulinum toxin (BOTULINUM TOXINS). The organism and its spores are widely distributed in nature.DNA Primers: 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.Plasmids: 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.Phylogeny: The relationships of groups of organisms as reflected by their genetic makeup.Trypsin: 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.Cysteine: A thiol-containing non-essential amino acid that is oxidized to form CYSTINE.Chromatography, High Pressure Liquid: Liquid chromatographic techniques which feature high inlet pressures, high sensitivity, and high speed.Lysine: An essential amino acid. It is often added to animal feed.Mutagenesis: Process of generating a genetic MUTATION. It may occur spontaneously or be induced by MUTAGENS.Amino Acid Transport Systems: Cellular proteins and protein complexes that transport amino acids across biological membranes.Genes, Bacterial: The functional hereditary units of BACTERIA.Sequence Analysis, DNA: A multistage process that includes cloning, physical mapping, subcloning, determination of the DNA SEQUENCE, and information analysis.Circular Dichroism: 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)Erabutoxins: Toxins isolated from the venom of Laticauda semifasciata, a sea snake (Hydrophid); immunogenic, basic polypeptides of 62 amino acids, folded by four disulfide bonds, block neuromuscular end-plates irreversibly, thus causing paralysis and severe muscle damage; they are similar to Elapid neurotoxins.Species Specificity: The restriction of a characteristic behavior, anatomical structure or physical system, such as immune response; metabolic response, or gene or gene variant to the members of one species. It refers to that property which differentiates one species from another but it is also used for phylogenetic levels higher or lower than the species.Cattle: 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.Cyanogen Bromide: 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.Aspartic Acid: 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.Leucine: An essential branched-chain amino acid important for hemoglobin formation.Proteins: 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.Catalysis: The facilitation of a chemical reaction by material (catalyst) that is not consumed by the reaction.Marine Toxins: Toxic or poisonous substances elaborated by marine flora or fauna. They include also specific, characterized poisons or toxins for which there is no more specific heading, like those from poisonous FISHES.Snake Venoms: Solutions or mixtures of toxic and nontoxic substances elaborated by snake (Ophidia) salivary glands for the purpose of killing prey or disabling predators and delivered by grooved or hollow fangs. They usually contain enzymes, toxins, and other factors.Membrane Proteins: 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.Carrier Proteins: Transport proteins that carry specific substances in the blood or across cell membranes.Codon: A set of three nucleotides in a protein coding sequence that specifies individual amino acids or a termination signal (CODON, TERMINATOR). Most codons are universal, but some organisms do not produce the transfer RNAs (RNA, TRANSFER) complementary to all codons. These codons are referred to as unassigned codons (CODONS, NONSENSE).Hydrolysis: The process of cleaving a chemical compound by the addition of a molecule of water.Amino Acids, Aromatic: Amino acids containing an aromatic side chain.Arginine: An essential amino acid that is physiologically active in the L-form.Tryptophan: 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.Sequence Deletion: Deletion of sequences of nucleic acids from the genetic material of an individual.Polymerase Chain Reaction: In vitro method for producing large amounts of specific DNA or RNA fragments of defined length and sequence from small amounts of short oligonucleotide flanking sequences (primers). The essential steps include thermal denaturation of the double-stranded target molecules, annealing of the primers to their complementary sequences, and extension of the annealed primers by enzymatic synthesis with DNA polymerase. The reaction is efficient, specific, and extremely sensitive. Uses for the reaction include disease diagnosis, detection of difficult-to-isolate pathogens, mutation analysis, genetic testing, DNA sequencing, and analyzing evolutionary relationships.Botulism: A disease caused by potent protein NEUROTOXINS produced by CLOSTRIDIUM BOTULINUM which interfere with the presynaptic release of ACETYLCHOLINE at the NEUROMUSCULAR JUNCTION. Clinical features include abdominal pain, vomiting, acute PARALYSIS (including respiratory paralysis), blurred vision, and DIPLOPIA. Botulism may be classified into several subtypes (e.g., food-borne, infant, wound, and others). (From Adams et al., Principles of Neurology, 6th ed, p1208)Magnetic Resonance Spectroscopy: 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).Crystallography, X-Ray: The study of crystal structure using X-RAY DIFFRACTION techniques. (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)RNA, Messenger: RNA sequences that serve as templates for protein synthesis. Bacterial mRNAs are generally primary transcripts in that they do not require post-transcriptional processing. Eukaryotic mRNA is synthesized in the nucleus and must be exported to the cytoplasm for translation. Most eukaryotic mRNAs have a sequence of polyadenylic acid at the 3' end, referred to as the poly(A) tail. The function of this tail is not known for certain, but it may play a role in the export of mature mRNA from the nucleus as well as in helping stabilize some mRNA molecules by retarding their degradation in the cytoplasm.Evolution, Molecular: The process of cumulative change at the level of DNA; RNA; and PROTEINS, over successive generations.Glycine: 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.Hydrogen-Ion Concentration: 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)Transfection: 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.Synaptosomal-Associated Protein 25: A ubiquitous target SNARE protein that interacts with SYNTAXIN and SYNAPTOBREVIN. It is a core component of the machinery for intracellular MEMBRANE FUSION. The sequence contains 2 SNARE domains, one is the prototype for the Qb-SNARES, and the other is the prototype for the Qc-SNARES.Macromolecular Substances: 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.Amino Acids, Basic: Amino acids with side chains that are positively charged at physiological pH.Saccharomyces cerevisiae: 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.Histidine: An essential amino acid that is required for the production of HISTAMINE.Elapidae: A family of extremely venomous snakes, comprising coral snakes, cobras, mambas, kraits, and sea snakes. They are widely distributed, being found in the southern United States, South America, Africa, southern Asia, Australia, and the Pacific Islands. The elapids include three subfamilies: Elapinae, Hydrophiinae, and Lauticaudinae. Like the viperids, they have venom fangs in the front part of the upper jaw. The mambas of Africa are the most dangerous of all snakes by virtue of their size, speed, and highly toxic venom. (Goin, Goin, and Zug, Introduction to Herpetology, 3d ed, p329-33)Scorpion Venoms: Venoms from animals of the order Scorpionida of the class Arachnida. They contain neuro- and hemotoxins, enzymes, and various other factors that may release acetylcholine and catecholamines from nerve endings. Of the several protein toxins that have been characterized, most are immunogenic.DNA Mutational Analysis: Biochemical identification of mutational changes in a nucleotide sequence.Isoleucine: An essential branched-chain aliphatic amino acid found in many proteins. It is an isomer of LEUCINE. It is important in hemoglobin synthesis and regulation of blood sugar and energy levels.Catalytic Domain: The region of an enzyme that interacts with its substrate to cause the enzymatic reaction.Serine: 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.Genes: A category of nucleic acid sequences that function as units of heredity and which code for the basic instructions for the development, reproduction, and maintenance of organisms.Endopeptidases: A subclass of PEPTIDE HYDROLASES that catalyze the internal cleavage of PEPTIDES or PROTEINS.Cell Membrane: The lipid- and protein-containing, selectively permeable membrane that surrounds the cytoplasm in prokaryotic and eukaryotic cells.Sequence Analysis: A multistage process that includes the determination of a sequence (protein, carbohydrate, etc.), its fragmentation and analysis, and the interpretation of the resulting sequence information.Cobra Venoms: Venoms from snakes of the genus Naja (family Elapidae). They contain many specific proteins that have cytotoxic, hemolytic, neurotoxic, and other properties. Like other elapid venoms, they are rich in enzymes. They include cobramines and cobralysins.Proline: 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.COS Cells: 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).)Protein Folding: Processes involved in the formation of TERTIARY PROTEIN STRUCTURE.Molecular Structure: 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.Enzyme Stability: 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.Gene Library: A large collection of DNA fragments cloned (CLONING, MOLECULAR) from a given organism, tissue, organ, or cell type. It may contain complete genomic sequences (GENOMIC LIBRARY) or complementary DNA sequences, the latter being formed from messenger RNA and lacking intron sequences.Disulfides: Chemical groups containing the covalent disulfide bonds -S-S-. The sulfur atoms can be bound to inorganic or organic moieties.Escherichia coli Proteins: Proteins obtained from ESCHERICHIA COLI.Open Reading Frames: A sequence of successive nucleotide triplets that are read as CODONS specifying AMINO ACIDS and begin with an INITIATOR CODON and end with a stop codon (CODON, TERMINATOR).Scorpions: Arthropods of the order Scorpiones, of which 1500 to 2000 species have been described. The most common live in tropical or subtropical areas. They are nocturnal and feed principally on insects and other arthropods. They are large arachnids but do not attack man spontaneously. They have a venomous sting. Their medical significance varies considerably and is dependent on their habits and venom potency rather than on their size. At most, the sting is equivalent to that of a hornet but certain species possess a highly toxic venom potentially fatal to humans. (From Dorland, 27th ed; Smith, Insects and Other Arthropods of Medical Importance, 1973, p417; Barnes, Invertebrate Zoology, 5th ed, p503)Protein Processing, Post-Translational: 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.Epitopes: Sites on an antigen that interact with specific antibodies.Mutation, Missense: 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)Peptide Mapping: 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.Cricetinae: A subfamily in the family MURIDAE, comprising the hamsters. Four of the more common genera are Cricetus, CRICETULUS; MESOCRICETUS; and PHODOPUS.Mass Spectrometry: An analytical method used in determining the identity of a chemical based on its mass using mass analyzers/mass spectrometers.Protein PrecursorsChymotrypsin: 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.Asparagine: 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)Threonine: 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.DNA, Bacterial: Deoxyribonucleic acid that makes up the genetic material of bacteria.Glutamine: 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.Transcription, Genetic: The biosynthesis of RNA carried out on a template of DNA. The biosynthesis of DNA from an RNA template is called REVERSE TRANSCRIPTION.Biological Transport: The movement of materials (including biochemical substances and drugs) through a biological system at the cellular level. The transport can be across cell membranes and epithelial layers. It also can occur within intracellular compartments and extracellular compartments.Glutamic Acid: A non-essential amino acid naturally occurring in the L-form. Glutamic acid is the most common excitatory neurotransmitter in the CENTRAL NERVOUS SYSTEM.Viral Proteins: Proteins found in any species of virus.Sequence Analysis, Protein: 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.Amino Acids, SulfurPlant Proteins: Proteins found in plants (flowers, herbs, shrubs, trees, etc.). The concept does not include proteins found in vegetables for which VEGETABLE PROTEINS is available.Phenylalanine: An essential aromatic amino acid that is a precursor of MELANIN; DOPAMINE; noradrenalin (NOREPINEPHRINE), and THYROXINE.Chromatography, Gel: Chromatography on non-ionic gels without regard to the mechanism of solute discrimination.Protein Sorting Signals: Amino acid sequences found in transported proteins that selectively guide the distribution of the proteins to specific cellular compartments.Oligopeptides: Peptides composed of between two and twelve amino acids.Temperature: 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.Valine: A branched-chain essential amino acid that has stimulant activity. It promotes muscle growth and tissue repair. It is a precursor in the penicillin biosynthetic pathway.Rabbits: 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.Oxocins: Compounds based on an 8-membered heterocyclic ring including an oxygen. They can be considered medium ring ethers.Tyrosine: A non-essential amino acid. In animals it is synthesized from PHENYLALANINE. It is also the precursor of EPINEPHRINE; THYROID HORMONES; and melanin.Gene Expression: The phenotypic manifestation of a gene or genes by the processes of GENETIC TRANSCRIPTION and GENETIC TRANSLATION.Cells, Cultured: 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.Oligodeoxyribonucleotides: 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.DNA-Binding Proteins: 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.Protein Biosynthesis: The biosynthesis of PEPTIDES and PROTEINS on RIBOSOMES, directed by MESSENGER RNA, via TRANSFER RNA that is charged with standard proteinogenic AMINO ACIDS.Methionine: A sulfur-containing essential L-amino acid that is important in many body functions.Chemistry: A basic science concerned with the composition, structure, and properties of matter; and the reactions that occur between substances and the associated energy exchange.Dimerization: The process by which two molecules of the same chemical composition form a condensation product or polymer.Chickens: 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.Bungarotoxins: Neurotoxic proteins from the venom of the banded or Formosan krait (Bungarus multicinctus, an elapid snake). alpha-Bungarotoxin blocks nicotinic acetylcholine receptors and has been used to isolate and study them; beta- and gamma-bungarotoxins act presynaptically causing acetylcholine release and depletion. Both alpha and beta forms have been characterized, the alpha being similar to the large, long or Type II neurotoxins from other elapid venoms.Chemical Phenomena: The composition, conformation, and properties of atoms and molecules, and their reaction and interaction processes.Phosphorylation: The introduction of a phosphoryl group into a compound through the formation of an ester bond between the compound and a phosphorus moiety.Bungarus: A genus of poisonous snakes of the subfamily Elapinae of the family ELAPIDAE. They comprise the kraits. Twelve species are recognized and all inhabit southeast Asia. They are considered extremely dangerous. (Moore: Poisonous Snakes of the World, 1980, p120)Chromatography, Ion Exchange: 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.Blotting, Northern: Detection of RNA that has been electrophoretically separated and immobilized by blotting on nitrocellulose or other type of paper or nylon membrane followed by hybridization with labeled NUCLEIC ACID PROBES.Multigene Family: A set of genes descended by duplication and variation from some ancestral gene. Such genes may be clustered together on the same chromosome or dispersed on different chromosomes. Examples of multigene families include those that encode the hemoglobins, immunoglobulins, histocompatibility antigens, actins, tubulins, keratins, collagens, heat shock proteins, salivary glue proteins, chorion proteins, cuticle proteins, yolk proteins, and phaseolins, as well as histones, ribosomal RNA, and transfer RNA genes. The latter three are examples of reiterated genes, where hundreds of identical genes are present in a tandem array. (King & Stanfield, A Dictionary of Genetics, 4th ed)Ligands: 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)Genetic Variation: Genotypic differences observed among individuals in a population.Serine Endopeptidases: Any member of the group of ENDOPEPTIDASES containing at the active site a serine residue involved in catalysis.Swine: 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).Models, Chemical: Theoretical representations that simulate the behavior or activity of chemical processes or phenomena; includes the use of mathematical equations, computers, and other electronic equipment.Glycosylation: 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.Genetic Complementation Test: A test used to determine whether or not complementation (compensation in the form of dominance) will occur in a cell with a given mutant phenotype when another mutant genome, encoding the same mutant phenotype, is introduced into that cell.CHO Cells: 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.Cercopithecus aethiops: 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.Botulinum Antitoxin: Antiserum given therapeutically in BOTULISM.Spider Venoms: Venoms of arthropods of the order Araneida of the ARACHNIDA. The venoms usually contain several protein fractions, including ENZYMES, hemolytic, neurolytic, and other TOXINS, BIOLOGICAL.R-SNARE Proteins: SNARE proteins where the central amino acid residue of the SNARE motif is an ARGININE. They are classified separately from the Q-SNARE PROTEINS where the central amino acid residue of the SNARE motif is a GLUTAMINE. This subfamily contains the vesicle associated membrane proteins (VAMPs) based on similarity to the prototype for the R-SNAREs, VAMP2 (synaptobrevin 2).Oligonucleotide Probes: Synthetic or natural oligonucleotides used in hybridization studies in order to identify and study specific nucleic acid fragments, e.g., DNA segments near or within a specific gene locus or gene. The probe hybridizes with a specific mRNA, if present. Conventional techniques used for testing for the hybridization product include dot blot assays, Southern blot assays, and DNA:RNA hybrid-specific antibody tests. Conventional labels for the probe include the radioisotope labels 32P and 125I and the chemical label biotin.Antibodies, Monoclonal: Antibodies produced by a single clone of cells.Binding, Competitive: 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.Reptilian Proteins: Proteins obtained from species of REPTILES.Fungal Proteins: Proteins found in any species of fungus.Exons: The parts of a transcript of a split GENE remaining after the INTRONS are removed. They are spliced together to become a MESSENGER RNA or other functional RNA.Blotting, Southern: A method (first developed by E.M. Southern) for detection of DNA that has been electrophoretically separated and immobilized by blotting on nitrocellulose or other type of paper or nylon membrane followed by hybridization with labeled NUCLEIC ACID PROBES.Liver: A large lobed glandular organ in the abdomen of vertebrates that is responsible for detoxification, metabolism, synthesis and storage of various substances.Phenotype: The outward appearance of the individual. It is the product of interactions between genes, and between the GENOTYPE and the environment.Thermodynamics: 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)Protein Engineering: Procedures by which protein structure and function are changed or created in vitro by altering existing or synthesizing new structural genes that direct the synthesis of proteins with sought-after properties. Such procedures may include the design of MOLECULAR MODELS of proteins using COMPUTER GRAPHICS or other molecular modeling techniques; site-specific mutagenesis (MUTAGENESIS, SITE-SPECIFIC) of existing genes; and DIRECTED MOLECULAR EVOLUTION techniques to create new genes.Hydrogen Bonding: 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.Oxidation-Reduction: 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).Carbohydrates: The largest class of organic compounds, including STARCH; GLYCOGEN; CELLULOSE; POLYSACCHARIDES; and simple MONOSACCHARIDES. Carbohydrates are composed of carbon, hydrogen, and oxygen in a ratio of Cn(H2O)n.Transcription Factors: Endogenous substances, usually proteins, which are effective in the initiation, stimulation, or termination of the genetic transcription process.Amino Acids, Branched-Chain: Amino acids which have a branched carbon chain.Hydrophobic and Hydrophilic Interactions: The thermodynamic interaction between a substance and WATER.HeLa Cells: 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.Carboxypeptidases: Enzymes that act at a free C-terminus of a polypeptide to liberate a single amino acid residue.Amino Acid Transport Systems, Basic: Amino acid transporter systems capable of transporting basic amino acids (AMINO ACIDS, BASIC).Amino Acids, DiaminoSnakes: Limbless REPTILES of the suborder Serpentes.Glycoproteins: Conjugated protein-carbohydrate compounds including mucins, mucoid, and amyloid glycoproteins.Amino Acids, Acidic: Amino acids with side chains that are negatively charged at physiological pH.Stereoisomerism: The phenomenon whereby compounds whose molecules have the same number and kind of atoms and the same atomic arrangement, but differ in their spatial relationships. (From McGraw-Hill Dictionary of Scientific and Technical Terms, 5th ed)Consensus Sequence: A theoretical representative nucleotide or amino acid sequence in which each nucleotide or amino acid is the one which occurs most frequently at that site in the different sequences which occur in nature. The phrase also refers to an actual sequence which approximates the theoretical consensus. A known CONSERVED SEQUENCE set is represented by a consensus sequence. Commonly observed supersecondary protein structures (AMINO ACID MOTIFS) are often formed by conserved sequences.Nerve Tissue ProteinsIsoenzymes: Structurally related forms of an enzyme. Each isoenzyme has the same mechanism and classification, but differs in its chemical, physical, or immunological characteristics.Plants: Multicellular, eukaryotic life forms of kingdom Plantae (sensu lato), comprising the VIRIDIPLANTAE; RHODOPHYTA; and GLAUCOPHYTA; all of which acquired chloroplasts by direct endosymbiosis of CYANOBACTERIA. They are characterized by a mainly photosynthetic mode of nutrition; essentially unlimited growth at localized regions of cell divisions (MERISTEMS); cellulose within cells providing rigidity; the absence of organs of locomotion; absence of nervous and sensory systems; and an alternation of haploid and diploid generations.Membrane Transport Proteins: Membrane proteins whose primary function is to facilitate the transport of molecules across a biological membrane. Included in this broad category are proteins involved in active transport (BIOLOGICAL TRANSPORT, ACTIVE), facilitated transport and ION CHANNELS.Sequence Homology: The degree of similarity between sequences. Studies of AMINO ACID SEQUENCE HOMOLOGY and NUCLEIC ACID SEQUENCE HOMOLOGY provide useful information about the genetic relatedness of genes, gene products, and species.Chromosome Mapping: Any method used for determining the location of and relative distances between genes on a chromosome.Chromatography, Affinity: 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)Saccharomyces cerevisiae Proteins: 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.Mutant Proteins: Proteins produced from GENES that have acquired MUTATIONS.Alleles: Variant forms of the same gene, occupying the same locus on homologous CHROMOSOMES, and governing the variants in production of the same gene product.
... is a 4958 Da peptide containing 48 amino acid residues. The primary structure is depicted in Table 1. Substitution ... The major neurotoxin BcIII (BcIII) isolated from Bunodosoma caissarum is homologous to cangitoxin. It has two homologous amino ... contains in addition to the previous substitution, a replacement of the 14th amino acid, arginine (R), into histidine (H). ... of the 16th amino acid, asparagine (N), into an aspartic acid (D) is named cangitoxin-II (CGTX-II). Cangitoxin-III (CGTX-III) ...
A better understanding of these differences might offer insights about the function of particular amino acid residues. Despite ... In the mature CLX, one base-pair substitution is responsible for a single glutamic acid to lysine replacement in the coding ... Calitoxin, also known as CLX, is a sea anemone neurotoxin produced by the sea anemone Calliactis parasitica. It targets crabs ... The amino acid sequence is markedly dissimilar from other known sea anemones toxins. There are two known genes coding for two ...
... which is composed of a cysteine residue followed by 13 amino acid residues and another cysteine residue. The two cysteine ... Postsynaptic neurotoxins, otherwise known as α-neurotoxins, act oppositely to the presynaptic neurotoxins by binding to the ... Single nucleotide substitutions or deletions may cause loss of function in the subunit. Other mutations, such as those ... Venoms can act as both presynaptic and postsynaptic neurotoxins. Presynaptic neurotoxins, commonly known as β-neurotoxins, ...
The 3FP protein domain has no enzymatic activity and is typically between 60-74 amino acid residues long. Despite their ... "The Effect of the Single Substitution of Arginine within the RGD Tripeptide Motif of a Modified Neurotoxin Dendroaspin on Its ... The proteins are typically 60-74 amino acid residues long, though some have additional N- or C-terminal extensions. An ... Most members of the family are neurotoxins that act on cholinergic intercellular signaling; the alpha-neurotoxin family ...
The active site consists of amino acid residues that form temporary bonds with the substrate (binding site) and residues that ... When it binds to the enzyme a nucleophilic substitution reaction occurs and releases one hydrogen fluoride molecule. The OH ... Strychnine is a neurotoxin that causes death by affecting nerves that control muscular contraction and cause respiration ... The active site usually contains non-polar amino acids, although sometimes polar amino acids may also occur.[2] The binding of ...
It appears that growth factors, amino acids, ATP, and oxygen levels regulate mTOR signaling. Several downstream pathways that ... Everolimus has O-2 hydroxyethyl chain substitution and deforolimus has a phosphine oxide substitution at position C-43 in the ... in the way by blocking both mTORC1-dependent phospholylation of S6K1 and mTORC2-dependent phosphorylation of AKT Ser473 residue ... Temsirolimus is a dihydroxymethyl propionic acid ester of rapamycin, and its first derivative.[2] Therefore, it is more water- ...
... is the linear sequence of amino acids in a peptide or protein. By convention, the primary structure of a protein is reported starting from the amino-terminal (N) end to the carboxyl-terminal (C) end. Protein biosynthesis is most commonly performed by ribosomes in cells. Peptides can also be synthesized in the laboratory[citation needed]. Protein primary structures can be directly sequenced, or inferred from DNA sequences. Amino acids are polymerised via peptide bonds to form a long backbone, with the different amino acid side chains protruding along it. In biological systems, proteins are produced during translation by a cell's ribosomes. Some organisms can also make short peptides by non-ribosomal peptide synthesis, which often use amino acids other than the standard ...
Proteins (/ˈproʊˌtiːnz/ or /ˈproʊti.ɪnz/) are large biomolecules, or macromolecules, consisting of one or more long chains of amino acid residues. Proteins perform a vast array of functions within organisms, including catalysing metabolic reactions, DNA replication, responding to stimuli, and transporting molecules from one location to another. Proteins differ from one another primarily in their sequence of amino acids, which is dictated by the nucleotide sequence of their genes, and which usually results in protein folding into a specific three-dimensional structure that determines its activity.. A linear chain of amino acid residues is called a polypeptide. A protein contains at least one long polypeptide. Short polypeptides, containing less than 20-30 residues, are rarely considered to be proteins and are ...
... s are lairge biological molecules, or macromolecules, consistin o ane or mair chains o amino acid residues. Proteins perform a vast array o functions athin organisms, includin catalysin metabolic reactions, DNA replication, respondin tae stimuli, an transportin molecules frae ane location tae anither. Proteins differ frae ane anither primarily in thair sequence o amino acids, that is dictatit bi the nucleotide sequence o thair genes, an that uisually results in protein foldin intae a speceefic three-dimensional structur that determines its acteevity. A linear cheen o amino acid residues is cried a polypeptide. A protein conteens at least ane lang polypeptide. Short polypeptides, conteenin less nor 20-30 residues, are rarely conseedert tae be proteins an are commonly cried peptides, or whiles ...
... s are large biomolecules, or macromolecules, consisting of one or more long chains of amino acid residues. Proteins perform a vast array of functions within organisms, including catalysing metabolic reactions, DNA replication, responding to stimuli, providing structure to cells, and organisms, and transporting molecules from one location to another. Proteins differ from one another primarily in their sequence of amino acids, which is dictated by the nucleotide sequence of their genes, and which usually results in protein folding into a specific three-dimensional structure that determines its activity. A linear chain of amino acid residues is called a polypeptide. A protein contains at least one long polypeptide. Short polypeptides, containing less than 20-30 residues, are rarely considered to be proteins ...
... s are large biomolecules, or macromolecules, consisting of one or more long chains of amino acid residues. Proteins perform a vast array of functions within organisms, including catalysing metabolic reactions, DNA replication, responding to stimuli, providing structure to cells, and organisms, and transporting molecules from one location to another. Proteins differ from one another primarily in their sequence of amino acids, which is dictated by the nucleotide sequence of their genes, and which usually results in protein folding into a specific three-dimensional structure that determines its activity. A linear chain of amino acid residues is called a polypeptide. A protein contains at least one long polypeptide. Short polypeptides, containing less than 20-30 residues, are rarely considered to be proteins ...
... s are large biomolecules, or macromolecules, consisting of one or more long chains of amino acid residues. Proteins perform a vast array of functions within organisms, including catalysing metabolic reactions, DNA replication, responding to stimuli, providing structure to cells and organisms, and transporting molecules from one location to another. Proteins differ from one another primarily in their sequence of amino acids, which is dictated by the nucleotide sequence of their genes, and which usually results in protein folding into a specific three-dimensional structure that determines its activity. A linear chain of amino acid residues is called a polypeptide. A protein contains at least one long polypeptide. Short polypeptides, containing less than 20-30 residues, are rarely considered to be proteins ...
... s are large biomolecules, or macromolecules, consisting of one or more long chains of amino acid residues. Proteins perform a vast array of functions within organisms, including catalysing metabolic reactions, DNA replication, responding to stimuli, providing structure to cells and organisms, and transporting molecules from one location to another. Proteins differ from one another primarily in their sequence of amino acids, which is dictated by the nucleotide sequence of their genes, and which usually results in protein folding into a specific three-dimensional structure that determines its activity. A linear chain of amino acid residues is called a polypeptide. A protein contains at least one long polypeptide. Short polypeptides, containing less than 20-30 residues, are rarely considered to be proteins ...
... s (/ˈproʊˌtiːnz/ or /ˈproʊti.ɪnz/) are large biomolecules, or macromolecules, consisting of one or more long chains of amino acid residues. Proteins perform a vast array of functions within organisms, including catalysing metabolic reactions, DNA replication, responding to stimuli, and transporting molecules from one location to another. Proteins differ from one another primarily in their sequence of amino acids, which is dictated by the nucleotide sequence of their genes, and which usually results in protein folding into a specific three-dimensional structure that determines its activity.. A linear chain of amino acid residues is called a polypeptide. A protein contains at least one long polypeptide. Short polypeptides, containing less than 20-30 residues, are rarely considered to be proteins and are ...
For the Tetris game, see Tetris: The Grand Master. Protein-glutamine gamma-glutamyltransferase E is an enzyme that in humans is encoded by the TGM3 gene. Transglutaminases are enzymes that catalyze the crosslinking of proteins by epsilon-gamma glutamyl lysine isopeptide bonds. While the primary structure of transglutaminases is not conserved, they all have the same amino acid sequence at their active sites and their activity is calcium-dependent. The protein encoded by this gene consists of two polypeptide chains activated from a single precursor protein by proteolysis. The encoded protein is involved the later stages of cell envelope formation in the epidermis and hair follicle. Proximal promoter GRCh38: Ensembl release 89: ENSG00000125780 - Ensembl, May 2017 GRCm38: Ensembl release 89: ENSMUSG00000027401 - Ensembl, May 2017 "Human PubMed Reference:". "Mouse PubMed Reference:". Wang M, Kim IG, Steinert PM, McBride OW (Mar 1995). "Assignment of the human ...
In bioinformatics, a sequence alignment is a way of arranging the sequences of DNA, RNA, or protein to identify regions of similarity that may be due to functional, structural, or evolutionary relationships between the sequences.[9] If two sequences in an alignment share a common ancestor, mismatches can be interpreted as point mutations and gaps as insertion or deletion mutations (indels) introduced in one or both lineages in the time since they diverged from one another. In sequence alignments of proteins, the degree of similarity between amino acids occupying a particular position in the sequence can be interpreted as a rough measure of how conserved a particular region or sequence motif is among lineages. The absence of substitutions, or the presence of only very conservative substitutions (that is, the substitution of amino acids whose side chains have ...
Kamphuis, I.G., Drenth, J. and Baker, E.N. (1985). „Thiol proteases. Comparative studies based on the high-resolution structures of papain and actinidin, and on amino acid sequence information for cathepsins B and H, and stem bromelain". J. Mol. Biol. 182: 317-329. PMID 3889350 ...
பல அமினோ அமிலங்கள் பெப்டைடு இணைப்புகளால் இணைவதால் ஓர் புரதம் அல்லது பல்புரதக்கூறு உருவாகும். இவ்வகை நீண்ட சங்கிலித் தொடர் அமைப்பு புரதத்தின் முதல்நிலை அமைப்பு (primary structure) என்று அழைக்கப்படும். இச்சங்கிலித் தொடர் அமைப்பில் காணப்படும் அணுக்களுக்கிடையே ஏற்படும் இடைத்தாக்கங்களால், சங்கிலியில் ஏற்படும் மடிவுகள் காரணமாக ஏற்படும் அமைப்பு இரண்டாம்நிலை (secondary structure) அமைப்பு ...
ಅಮಿನೊ ಆಮ್ಲಗಳು[ಟಿಪ್ಪಣಿ ೧] ಜೈವಿಕವಾಗಿ ಮುಖ್ಯವಾದ ಅಮೈನ್ (-NH2) ಮತ್ತು ಕಾರ್ಬೋಕ್ಸಿಲಿಕ್ ಆಮ್ಲ (-COOH) ಕ್ರಿಯಾ ಗುಂಪುಗಳಿರುವ ಸಾವಯವ ಸಂಯುಕ್ತಗಳು. ಅಲ್ಲದೆ ಸಾಮಾನ್ಯವಾಗಿ ಪ್ರತಿ ಅಮಿನೊ ಆಮ್ಲಕ್ಕೂ ವಿಶಿಷ್ಟವಾಗಿರುವ ಪಕ್ಕದ-ಸರಪಳಿ ಸಹ ಇರುತ್ತದೆ.[೧][೨][೩] ಅಮಿನೊ ಆಮ್ಲದ ಪ್ರಮುಖ ಧಾತುಗಳು ಇಂಗಾಲ, ಜಲಜನಕ, ಆಮ್ಲಜನಕ ಮತ್ತು ಸಾರಜನಕಗಳು, ಆದರೆ ಕೆಲವೊಂದು ಅಮಿನೊ ಆಮ್ಲಗಳ ಪಕ್ಕದ-ಸರಪಳಿಯಲ್ಲಿ ಬೇರೆ ಧಾತುಗಳಿರುತ್ತವೆ. ಸುಮಾರು ೫೦೦ ಅಮಿನೊ ಆಮ್ಲಗಳು ತಿಳಿದಿದ್ದು ...
Cangitoxin is a 4958 Da peptide containing 48 amino acid residues. The primary structure is depicted in Table 1. Substitution ... The major neurotoxin BcIII (BcIII) isolated from Bunodosoma caissarum is homologous to cangitoxin. It has two homologous amino ... contains in addition to the previous substitution, a replacement of the 14th amino acid, arginine (R), into histidine (H). ... of the 16th amino acid, asparagine (N), into an aspartic acid (D) is named cangitoxin-II (CGTX-II). Cangitoxin-III (CGTX-III) ...
High Rate of Amino Acid Substitution in the Branch a-b.. To evaluate the absolute rate of amino acid substitution in the branch ... and dots show the same amino acids as those of the sequence at node a. The arginine (R) residues of ECP and EDN are shown in ... eosinophil-derived neurotoxin;. OW,. Old World;. NW,. New World;. RNase,. ribonuclease;. NG,. Nei-Gojobori;. Myr,. million ... Nonrandom Amino Acid Substitution.. It is of great interest to identify the amino acid substitutions that produced the novel ...
The replacement of some internal amino acid residues with single or multiple substitutions led to further improvement. An ... Amino Acid Sequence Article Botulinum Neurotoxin Botulinum Toxins, Type A Botulism Detection Endopeptidases Immunoglobulin G ... Botulinum neurotoxins (BoNTs) are a family of protein toxins consisting of seven known serotypes (BoNT/A-BoNT/G) and multiple ... Botulinum neurotoxins (BoNTs) are a family of seven toxin serotypes that are the most toxic substances known to humans. ...
... of conservative substitutions per site (P,0.02; Fishers exact test). There are nine amino-acid substitutions in the mature ... Equally important, either the new or the ancestral motif must contain amino acid residues that are not too highly degenerate in ... The genes for eosinophil cationic protein (ECP) and eosinophil-derived neurotoxin (EDN) in primates belong to the ribonuclease ... Each enzyme consists of 475 amino acids and differs by only 9 amino acids. AtzA was shown to exclusively catalyze ...
... of conservative substitutions per site (P,0.02; Fishers exact test). There are nine amino-acid substitutions in the mature ... 3. Chains of optimal length close the ends by interactions between two amino acid residues.. 4. The loops are joined in linear ... The genes for eosinophil cationic protein (ECP) and eosinophil-derived neurotoxin (EDN) in primates belong to the ribonuclease ... These complementary DNAs encode 22 distinct Milk peptides, each of length 171 amino acids, including a 16-amino acid signal ...
This study reports the presence of two additional amino acid substitutions in the VGSC of an An. culicifacies population from ... A third and novel substitution, Val (GTG)-to-Leu (TTG or CTG), was identified at residue V1010 resulting from either of the two ... culicifacies individuals collected from district Malkangiri revealed the presence of three amino acid substitutions in the IIS6 ... using PIRA-PCR assays for 1014S and ARMS for 1014F alleles revealed the presence of all the three amino acid substitutions in ...
An alteration in the precursor amino acids has the potential to impact monoamine neurotransmitter synthesis in the brain.. ... Our findings represent the first identification of a residue in monoamine neurotransmitter transporters whose substitution ... A 16-module online course about the management of monoamine neurotransmitter disease and of neurotoxins according to the Bundle ... Liquid chromatographic-tandem mass spectrometric method for the determination of 5-hydroxyindole-3-acetic acid in urine ...
... are composed of 121 and 122 amino acids determined by automated sequencing of the native proteins and peptides produced by ... The presence of two short clusters of hydrophobic/basic amino acids residues 61-71 and 105-117 (Figure 2, this work) is ... is used for identical residues (:) for conserved ones and (.) for semi-conserved substitutions among all sequences in the ... For instance, vipoxin, a heterodimeric post-synaptic neurotoxin found in V. ammodytes meridionalis, consists of two PLA2 ...
... is a critical residue for sustaining normal SNAP-25 activity because its substitution for alanine or glutamic acid produced a ... botulinum neurotoxin;. GFP,. green fluorescent protein;. SNAP-25,. synaptosome-associated protein of 25 kDa;. SNARE,. soluble N ... The lack (in SNAP-25 deleted constructs) or substitution (in mutated SNAP-25) of this amino acid might reduce the likelihood of ... in which Leu203 was replaced by an amino acid of similar size but negatively charged, such as glutamic acid [GFP-S-25 (L203E ...
2002). Effects of Amino Acid Substitutions at ?131 on the Structure and Properties of Hemoglobin:? Evidence for Communication ... 2014). Comparison of Backbone Modification in Protein ?-Sheets by ??? Residue Replacement and ?-Residue Methylation.. Organic ... 2010). Structure and stability of the neurotoxin PV2 from the eggs of the apple snailPomacea canaliculata.. BBA Proteins and ... 2014). Structural Similarity between ?3-Peptides Synthesized from ??3-Homo-amino Acids or L-Aspartic Acid Monomers.. Peptide ...
A specific 25-amino acid-fragment (residue positions 30-54) of the α4 nAChR cytoplasmatic loop targeted the chimera to axons. A ... This means that a single amino acid substitution can determine sensitivity or resistance to a snake venom. ... The α-neurotoxins from snake venoms are potent antagonists of nicotinic acetylcholine receptors. In mouse some of them are over ... 1.2.1. Single amino acid changes. Single amino acid changes can be used to investigate the role of amino acids in the binding ...
Recombinant Botulinum neurotoxin serotype A (R362A, Y365F), termed BoNT/A(RY), is a product of two amino acid substitutions ... The loss of two key histidine and glutamic acid residues prevented the binding of cofactors zinc and a single water molecule ... X7 = Any amino acid(s) or Des X;. *"Des X" = "an amino acid does not have to be present at this position." For example if a ... BOTULINUM NEUROTOXIN. Note: nucleic acids that encode for the less potent or toxic form of the specific Botulinum neurotoxin ...
A single base (A-T) change in the knock-down resistance (kdr) allele leads to an amino acid substitution at position 267 that ... A number of modules have been developed for predicting neurotoxins using residue composition based on feed-forwarded neural ... We have also developed SVM modules for classifying neurotoxins based on functions using amino acid, dipeptide composition and ... By using the Hidden Markov Model (HMM) profile built from the alignment of a 99 amino acid conserved domain sequence of 273 ...
methylamino-l-alanine - amino-acid - mass-spectrometry - cyanobacteria - chromatography - seeds - guam. The neurotoxin ß-N- ... human infection - amino-acid - poultry - host - transmission - substitution - pathogenesis - determinant - adaptation - ... Because of the presence of diaminoisoidide residues the synthesized fully renewable products exhibit tunable polarities and ... In sheep, susceptibility to disease is genetically influenced by single amino acid substitutions. Genetic breeding programs ...
A better understanding of these differences might offer insights about the function of particular amino acid residues. Despite ... In the mature CLX, one base-pair substitution is responsible for a single glutamic acid to lysine replacement in the coding ... Calitoxin, also known as CLX, is a sea anemone neurotoxin produced by the sea anemone Calliactis parasitica. It targets crabs ... The amino acid sequence is markedly dissimilar from other known sea anemones toxins. There are two known genes coding for two ...
... conservative substitutions of the S3 Asp residue with Glu and with a neutral keto analog of Asp, 2-amino-4-ketopentanoic acid, ... The plant channels are also sensitive to a class of neurotoxins that exhibit high specificity in binding around the mouth of ... However, substitutions with each of the other nonaromatic amino acids also gave mutant KAT1 forms that activated variously at ... We interpret these findings in the context of the effects on hydration of amino acid residues within the VSD and with an ...
The single amino acid substitution between these two toxins maps at the tip of the first ß-stranded finger in the modeled ... This enzyme, which is Ca2+-dependent, is a 149 amino acid residue protein. The analysis of the A2-PLTX-Pcb1a sequence showed ... including one classical α-helical AMP and five ion channel-targeted neurotoxins. This AMP of 49 amino acids (named Meucin-49) ... mature Crassicorin-I represents a cationic AMP likely generated from a precursor and comprising 40 amino acid residues, ...
Nondetermined amino acid residues are indicated by (X); boxed amino acid residues are identical. The highlighted amino acid ... The substitution of Ca2+ by Mg2+, Cd2+, and Mn2+ also reduced the activity to levels similar to those in the absence of Ca2+ ( ... A comparative analysis of the sequence of Bbil-TX PLA2 with other neurotoxins "ex vivo" and myotoxic PLA2s belonging to ... Amino Acid Analysis. Amino acid analysis was performed on a Pico-Tag Analyzer (Waters Systems) as described by [16]. The ...
Lang, A. E., Neumeyer, T., Sun, J., Collier, R. J., Benz, R., and Aktories, K. (2008). Amino acid residues involved in membrane ... and are in units of the number of amino acid substitutions per site. All positions containing gaps and missing data were ... Kistner, A., and Habermann, E. (1992). Reductive cleavage of tetanus toxin and botulinum neurotoxin A by the thioredoxin system ... harboring conserved amino acids for catalysis. Mutation of the first glutamic acid in the EXE motif of C2I prevents ADP- ...
Amino acid substitutions resulting from suppression of nonsense mutations.. However, there is no study for the neurological ... The effect of botulinum neurotoxin type-A (BoNTA) on primary stabbing headache was investigated in 24 patients. ... gas chromatography linked to ion-trap tandem mass spectrometry for the fast trace analysis of multiclass pesticide residues. ...
... are called omega or gating pore currents.Gating pores are caused by mutations of the highly conserved positively charged amino ... acids in the S4 segment that disrupt interactions between the S4 segment and the gating charge transfer center (GCTC). The GCTC ... are called omega or gating pore currents.Gating pores are caused by mutations of the highly conserved positively charged amino ... acids in the S4 segment that disrupt interactions between the S4 segment and the gating charge transfer center (GCTC). The GCTC ...
... is explained on the basis of the orientations of amino-acid residues in the binding site. This structure is the first of its ... RNA molecules maintain the overall canonical A-type conformation upon substitution of single or multiple residues/nucleotides ... 3-F neurotoxins, Kunitz/basic pancreatic trypsin inhibitor (BPTI)-type inhibitors and a natriuretic peptide were identified in ... identical in the first 20 amino acid residues to the catalitically inactive acidic component of the heterodimeric PLA2 present ...
Two novel peptide toxins, acrorhagins I (50 amino acid residues) and II (44 amino acid residues), were isolated from the ... Zykova, TA, Kozlovskaya, EP 1989Amino acid sequence of neurotoxin I from the sea anemone Radianthus macrodactylus Bioorg Khim15 ... There are only four substitutions between both toxins. These toxins are featured by the presence of as many as 10 Cys residues ... Type 1 and 2 toxins are composed of 46 to 49 amino acid residues, except for Ae I of 54 residues (Lin et al., 1996), and cross- ...
Identical amino acids are shown using an asterisk. A colon identifies conserved substitutions, and a period is for less ... The four cysteine residues highlighted in red are conserved residues which associate the protein with the plasma membrane. The ... Botulinum neurotoxins serotypes A and E cleave SNAP-25 at distinct COOH-terminal peptide bonds. FEBS Letters 1993, 335 (1):99- ... conserved substitutions. Dashes allow for optimal alignment for amino acid insertions or deletions. Cleavage sites of BoNT/A ...
Metal substitution of tetanus neurotoxin Fiorella TONELLO, Giampietro SCHIAVO, Cesare MONTECUCCO. Biochemical Journal Mar 01, ... Amphibian embryo glutathione transferase: amino acid sequence and structural properties Paolo SACCHETTA, Raffaele PETRUZZELLI, ... Functional interaction of the carboxylic acid group of agonists and the arginine residue of the seventh transmembrane domain of ... Identification and partial characterization of a novel membrane glycoprotein induced by amino acid deprivation in renal ...
  • However, it has been controversial whether the functional divergence occurs by positive Darwinian selection that accelerates the fixation of advantageous mutations (largely nonsynonymous or amino acid-altering mutations) ( 6 ) or by random fixation of neutral mutations, which later induce a change in gene function when the environment or the genetic background is altered (Dykhuizen-Hartl effect) ( 7 , 8 ). (pnas.org)
  • Mutations of the central Phe residue favored the closed KAT1 channel, whereas mutations affecting the countercharge centers favored the open channel. (plantphysiol.org)
  • Gating pores are caused by mutations of the highly conserved positively charged amino acids in the S4 segment that disrupt interactions between the S4 segment and the gating charge transfer center (GCTC). (frontiersin.org)
  • From the initial analogs, a series of mutations with two alanine substitutions was synthesized. (aspetjournals.org)
  • In contrast, point mutations in the central region of α-synuclein, referred to as nonamyloid β component (residues 61-95), as well as point mutations linked to Parkinson's disease (A30P, E46K, and A53T) increased the neurotoxicity of α-synuclein but did not affect its physiological function in SNARE-complex assembly. (jneurosci.org)
  • Example current traces from one BKCa channels documented in the current presence of 2?M -DTX or Ala substitution mutations of -DTX at 6 different simple residues. (molecularcircuit.com)
  • Segura M, Lodeiro S, Meyer M, Patel A, Matsuda S. Directed evolution experiments reveal mutations at cycloartenol synthase residue His477 that dramatically alter catalysis. (labome.org)
  • The agent can include a clostridial neurotoxin, or a component or fragment or derivative thereof, attached to a targeting moiety, wherein the targeting moiety is selected from a group consisting of transmission compounds which can be released from neurons upon the transmission of pain signals by the neurons, and compounds substantially similar to the transmission compounds. (google.com)
  • It was also found that the number of arginine residues increased substantially in a short period of evolutionary time after gene duplication, and these amino acid changes probably produced the novel anti-pathogen function of ECP. (pnas.org)
  • the complex arises by an extended multi-site cation-anion interaction between lysine and arginine residues of the enzyme and phosphate groups of the nucleotides. (embl-heidelberg.de)
  • Methods for treating an injured muscle by local administration of a neurotoxin, such as a botulinum toxin, to promote healing and/or to reduce the pain associated with an injured muscle. (google.com)
  • 12. The method of claim 10 wherein the botulinum toxin is selected from the group consisting of botulinum neurotoxin types A, B, C, D, E, F, and G. (google.ca)
  • Tryptamine derivatives with substitutions at the 4 and 7 positions on the phenyl ring, the indole nitrogen, and the β position show up to 40-fold potency differences for inhibiting [ 3 H]5-HT transport in cells transfected with either human or Drosophila melanogaster SERT cDNAs. (aspetjournals.org)
  • The extraordinary potency of botulinum neurotoxins (BoNTs) is mediated by their high neurospecificity, targeting peripheral cholinergic motoneurons leading to flaccid paralysis and successive respiratory failure. (portlandpress.com)
  • In the latter case the rate of nonsynonymous nucleotide substitution may also be enhanced because of relaxation of functional constraints of redundant genes after gene duplication ( 8 ), but the rate will never exceed that of synonymous substitution. (pnas.org)
  • Growth with NE induces transcription of genes encoding the tyramine oxidase, TynA, and the aromatic aldehyde dehydrogenase, FeaB, whose respective activities can, in principle, convert NE to 3,4-dihydroxymandelic acid (DHMA). (asm.org)
  • 2008). Ligand-Induced Conformational Heterogeneity of Cytochrome P450 CYP119 Identified by 2D NMR Spectroscopy with the Unnatural Amino Acid 13C-p-Methoxyphenylalanine. (olisweb.com)
  • We have used site-directed mutagenesis to explore residues that are thought to form two electrostatic countercharge centers on either side of a conserved phenylalanine (Phe) residue within the S2 and S3 α-helices of the voltage sensor domain ( VSD ) of Kv channels. (plantphysiol.org)
  • The domain restriction imposed by toxin cleavage prompted us to design a new approach to the involvement of specific SNAREs residues in discrete stages of the exocytotic process. (pnas.org)
  • 15. The hybrid molecule of claim 3, wherein said toxin is botulinum neurotoxin. (google.com.au)
  • Here, we show that the traditionally defined insect-selective scorpion toxin LqhIT2 specifically captures a prey Nav through a conserved trapping apparatus comprising a three-residue-formed cavity and a structurally adjacent leucine. (bvsalud.org)
  • Thus, these data provide direct evidence for the involvement of a specific residue of SNAP-25 in exocytosis and show that overexpression of GFP-SNAP contructs combined with single vesicle fusion measurements constitutes a powerful approach to dissect the structural elements playing a role in individual steps of the exocytotic cascade. (pnas.org)
  • Chen K, Mizianty MJ, Kurgan L (2011) Prediction and analysis of nucleotide-binding residues using sequence and sequence-derived structural descriptors. (springer.com)
  • Within TMD I-II, species-scanning mutagenesis implicated a single residue (Y95 in human SERT, F90 in D. melanogaster SERT) in the recognition of NIT, 5-MNIT, and 7BT. (aspetjournals.org)
  • Control single-channel behavior of the BKCa route under these circumstances is comparable to that of underneath record in Fig. 1 that was taken in the current presence of 2?M calciseptine, an -neurotoxin homolog that will not induce substates. (molecularcircuit.com)
  • They form a family of enzymes, which require Ca 2+ and catalyze the hydrolysis of glycerophospholipids at the sn-2 position of the glycerol backbone to produce free fatty acids and lysophospholipids [ 6 ]. (mdpi.com)
  • Low pH caused by organic acids is a probable explanation for the effect of F. mume extract. (wur.nl)
  • Consistent with molecular dynamic simulations of KAT1, we show that the voltage dependence of the channel gate is highly sensitive to manipulations affecting these residues. (plantphysiol.org)
  • While histamine in fermented products, such as wine ( 36 ), cheese ( 35 , 59 ), and fish sauce ( 31 , 57 ), is produced by gram-positive lactic acid bacteria, histamine in raw fish products is caused mostly by gram-negative enteric bacteria such as Morganella morganii , Klebsiella spp. (asm.org)