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Aldose-Ketose Isomerases: Enzymes that catalyze the interconversion of aldose and ketose compounds.Isomerases: A class of enzymes that catalyze geometric or structural changes within a molecule to form a single product. The reactions do not involve a net change in the concentrations of compounds other than the substrate and the product.(from Dorland, 28th ed) EC 5.Carbon-Carbon Double Bond Isomerases: Enzymes that catalyze the shifting of a carbon-carbon double bond from one position to another within the same molecule. EC 5.3.3.Peptidylprolyl Isomerase: An enzyme that catalyzes the isomerization of proline residues within proteins. EC 5.2.1.8.Amino Acid Isomerases: Enzymes that catalyze either the racemization or epimerization of chiral centers within amino acids or derivatives. EC 5.1.1.Carbohydrate Epimerases: Enzymes that catalyze the epimerization of chiral centers within carbohydrates or their derivatives. EC 5.1.3.Protein Disulfide-Isomerases: Sulfur-sulfur bond isomerases that catalyze the rearrangement of disulfide bonds within proteins during folding. Specific protein disulfide-isomerase isoenzymes also occur as subunits of PROCOLLAGEN-PROLINE DIOXYGENASE.Steroid Isomerases: Enzymes that catalyze the transposition of double bond(s) in a steroid molecule. EC 5.3.3.Cyclophilins: A family of peptidyl-prolyl cis-trans isomerases that bind to CYCLOSPORINS and regulate the IMMUNE SYSTEM. EC 5.2.1.-Immunophilins: Members of a family of highly conserved proteins which are all cis-trans peptidyl-prolyl isomerases (PEPTIDYLPROLYL ISOMERASE). They bind the immunosuppressant drugs CYCLOSPORINE; TACROLIMUS and SIROLIMUS. They possess rotamase activity, which is inhibited by the immunosuppressant drugs that bind to them.Dodecenoyl-CoA Isomerase: A carbon-carbon double bond isomerase that catalyzes the movement double bond from C3 to C2 of an unsaturated acyl-CoA. The enzyme plays a key role in allowing acyl-CoA substrates to re-enter the beta-oxidation pathway.Tacrolimus Binding Proteins: A family of immunophilin proteins that bind to the immunosuppressive drugs TACROLIMUS (also known as FK506) and SIROLIMUS. EC 5.2.1.-Ammonium Hydroxide: The hydroxy salt of ammonium ion. It is formed when AMMONIA reacts with water molecules in solution.Cyclophilin A: A 17-KDa cytoplasmic PEPTIDYLPROLYL ISOMERASE involved in immunoregulation. It is a member of the cyclophilin family of proteins that binds to CYCLOSPORINE.Sulfur-Sulfur Bond Isomerases: Enzymes that catalyze the transposition of a sulfur-sulfur bond. EC 5.3.4.Pentoses: A class of carbohydrates that contains five carbon atoms.Glucose-6-Phosphate Isomerase: An aldose-ketose isomerase that catalyzes the reversible interconversion of glucose 6-phosphate and fructose 6-phosphate. In prokaryotic and eukaryotic organisms it plays an essential role in glycolytic and gluconeogenic pathways. In mammalian systems the enzyme is found in the cytoplasm and as a secreted protein. This secreted form of glucose-6-phosphate isomerase has been referred to as autocrine motility factor or neuroleukin, and acts as a cytokine which binds to the AUTOCRINE MOTILITY FACTOR RECEPTOR. Deficiency of the enzyme in humans is an autosomal recessive trait, which results in CONGENITAL NONSPHEROCYTIC HEMOLYTIC ANEMIA.Mannose-6-Phosphate Isomerase: An enzyme that catalyzes the reversible isomerization of D-mannose-6-phosphate to form D-fructose-6-phosphate, an important step in glycolysis. EC 5.3.1.8.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.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.Triose-Phosphate Isomerase: An enzyme that catalyzes reversibly the conversion of D-glyceraldehyde 3-phosphate to dihydroxyacetone phosphate. A deficiency in humans causes nonspherocytic hemolytic disease (ANEMIA, HEMOLYTIC, CONGENITAL NONSPHEROCYTIC). EC 5.3.1.1.Isomaltose: A disaccharide consisting of two glucose units in an alpha (1-6) glycosidic linkage.XyloseSequence 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.Metabolic Engineering: Methods and techniques used to genetically modify cells' biosynthetic product output and develop conditions for growing the cells as BIOREACTORS.Protein Folding: Processes involved in the formation of TERTIARY PROTEIN STRUCTURE.Substrate Specificity: A characteristic feature of enzyme activity in relation to the kind of substrate on which the enzyme or catalytic molecule reacts.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.Kinetics: The rate dynamics in chemical or physical systems.Thioredoxins: Hydrogen-donating proteins that participates in a variety of biochemical reactions including ribonucleotide reduction and reduction of PEROXIREDOXINS. Thioredoxin is oxidized from a dithiol to a disulfide when acting as a reducing cofactor. The disulfide form is then reduced by NADPH in a reaction catalyzed by THIOREDOXIN REDUCTASE.Molecular Chaperones: A family of cellular proteins that mediate the correct assembly or disassembly of polypeptides and their associated ligands. Although they take part in the assembly process, molecular chaperones are not components of the final structures.Catalysis: The facilitation of a chemical reaction by material (catalyst) that is not consumed by the reaction.Carrier Proteins: Transport proteins that carry specific substances in the blood or across cell membranes.Monosaccharides: Simple sugars, carbohydrates which cannot be decomposed by hydrolysis. They are colorless crystalline substances with a sweet taste and have the same general formula CnH2nOn. (From Dorland, 28th ed)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.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.Catalytic Domain: The region of an enzyme that interacts with its substrate to cause the enzymatic reaction.Pyrococcus furiosus: A species of strictly anaerobic, hyperthermophilic archaea which lives in geothermally-heated marine sediments. It exhibits heterotropic growth by fermentation or sulfur respiration.Cations, Divalent: Positively charged atoms, radicals or groups of atoms with a valence of plus 2, which travel to the cathode or negative pole during electrolysis.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.Base Sequence: The sequence of PURINES and PYRIMIDINES in nucleic acids and polynucleotides. It is also called nucleotide sequence.Bacillus: A genus of BACILLACEAE that are spore-forming, rod-shaped cells. Most species are saprophytic soil forms with only a few species being pathogenic.Binding Sites: The parts of a macromolecule that directly participate in its specific combination with another molecule.Isomerism: The phenomenon whereby certain chemical compounds have structures that are different although the compounds possess the same elemental composition. (From McGraw-Hill Dictionary of Scientific and Technical Terms, 5th ed)Models, Molecular: Models used experimentally or theoretically to study molecular shape, electronic properties, or interactions; includes analogous molecules, computer-generated graphics, and mechanical structures.Tacrolimus: A macrolide isolated from the culture broth of a strain of Streptomyces tsukubaensis that has strong immunosuppressive activity in vivo and prevents the activation of T-lymphocytes in response to antigenic or mitogenic stimulation in vitro.Genes, Bacterial: The functional hereditary units of BACTERIA.Hot Temperature: Presence of warmth or heat or a temperature notably higher than an accustomed norm.Streptomyces: A genus of bacteria that form a nonfragmented aerial mycelium. Many species have been identified with some being pathogenic. This genus is responsible for producing a majority of the ANTI-BACTERIAL AGENTS of practical value.Bacterial Proteins: Proteins found in any species of bacterium.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).Heat-Shock Proteins: Proteins which are synthesized in eukaryotic organisms and bacteria in response to hyperthermia and other environmental stresses. They increase thermal tolerance and perform functions essential to cell survival under these conditions.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.Cyclosporine: A cyclic undecapeptide from an extract of soil fungi. It is a powerful immunosupressant with a specific action on T-lymphocytes. It is used for the prophylaxis of graft rejection in organ and tissue transplantation. (From Martindale, The Extra Pharmacopoeia, 30th 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.Escherichia coli Proteins: Proteins obtained from ESCHERICHIA COLI.Recombinant Proteins: Proteins prepared by recombinant DNA technology.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.Disulfides: Chemical groups containing the covalent disulfide bonds -S-S-. The sulfur atoms can be bound to inorganic or organic moieties.Histidine: An essential amino acid that is required for the production of HISTAMINE.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.Isoenzymes: Structurally related forms of an enzyme. Each isoenzyme has the same mechanism and classification, but differs in its chemical, physical, or immunological characteristics.Crystallography, X-Ray: The study of crystal structure using X-RAY DIFFRACTION techniques. (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)Oxidoreductases: The class of all enzymes catalyzing oxidoreduction reactions. The substrate that is oxidized is regarded as a hydrogen donor. The systematic name is based on donor:acceptor oxidoreductase. The recommended name will be dehydrogenase, wherever this is possible; as an alternative, reductase can be used. Oxidase is only used in cases where O2 is the acceptor. (Enzyme Nomenclature, 1992, p9)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)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)Mutagenesis, Site-Directed: Genetically engineered MUTAGENESIS at a specific site in the DNA molecule that introduces a base substitution, or an insertion or deletion.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.Phylogeny: The relationships of groups of organisms as reflected by their genetic makeup.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.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.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).Endoplasmic Reticulum: A system of cisternae in the CYTOPLASM of many cells. In places the endoplasmic reticulum is continuous with the plasma membrane (CELL MEMBRANE) or outer membrane of the nuclear envelope. If the outer surfaces of the endoplasmic reticulum membranes are coated with ribosomes, the endoplasmic reticulum is said to be rough-surfaced (ENDOPLASMIC RETICULUM, ROUGH); otherwise it is said to be smooth-surfaced (ENDOPLASMIC RETICULUM, SMOOTH). (King & Stansfield, A Dictionary of Genetics, 4th ed)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.Genes, Fungal: The functional hereditary units of FUNGI.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.Restriction Mapping: Use of restriction endonucleases to analyze and generate a physical map of genomes, genes, or other segments of DNA.Molecular Weight: The sum of the weight of all the atoms in a molecule.Enzyme Inhibitors: Compounds or agents that combine with an enzyme in such a manner as to prevent the normal substrate-enzyme combination and the catalytic reaction.