Protein C: A vitamin-K dependent zymogen present in the blood, which, upon activation by thrombin and thrombomodulin exerts anticoagulant properties by inactivating factors Va and VIIIa at the rate-limiting steps of thrombin formation.Protein C Deficiency: An absence or deficiency in PROTEIN C which leads to impaired regulation of blood coagulation. It is associated with an increased risk of severe or premature thrombosis. (Stedman's Med. Dict., 26th ed.)Protein C Inhibitor: A member of the serpin family of proteins that is found in plasma and urine. It is dependent on heparin and is able to inhibit activated PROTEIN C; THROMBIN; KALLIKREIN; and other SERINE ENDOPEPTIDASES.Kinetics: The rate dynamics in chemical or physical systems.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.Catalysis: The facilitation of a chemical reaction by material (catalyst) that is not consumed by the reaction.Cell Line: Established cell cultures that have the potential to propagate indefinitely.Virus Replication: The process of intracellular viral multiplication, consisting of the synthesis of PROTEINS; NUCLEIC ACIDS; and sometimes LIPIDS, and their assembly into a new infectious particle.Activated Protein C Resistance: A hemostatic disorder characterized by a poor anticoagulant response to activated protein C (APC). The activated form of Factor V (Factor Va) is more slowly degraded by activated protein C. Factor V Leiden mutation (R506Q) is the most common cause of APC resistance.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.Base Sequence: The sequence of PURINES and PYRIMIDINES in nucleic acids and polynucleotides. It is also called nucleotide sequence.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.Viral Proteins: Proteins found in any species of virus.Protein S: The vitamin K-dependent cofactor of activated PROTEIN C. Together with protein C, it inhibits the action of factors VIIIa and Va. A deficiency in protein S; (PROTEIN S DEFICIENCY); can lead to recurrent venous and arterial thrombosis.Antiviral Agents: Agents used in the prophylaxis or therapy of VIRUS DISEASES. Some of the ways they may act include preventing viral replication by inhibiting viral DNA polymerase; binding to specific cell-surface receptors and inhibiting viral penetration or uncoating; inhibiting viral protein synthesis; or blocking late stages of virus assembly.Thrombomodulin: A cell surface glycoprotein of endothelial cells that binds thrombin and serves as a cofactor in the activation of protein C and its regulation of blood coagulation.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.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.Alkenes: Unsaturated hydrocarbons of the type Cn-H2n, indicated by the suffix -ene. (Grant & Hackh's Chemical Dictionary, 5th ed, p408)Blood Coagulation Factors: Endogenous substances, usually proteins, that are involved in the blood coagulation process.Palladium: A chemical element having an atomic weight of 106.4, atomic number of 46, and the symbol Pd. It is a white, ductile metal resembling platinum, and following it in abundance and importance of applications. It is used in dentistry in the form of gold, silver, and copper alloys.Pulmonary Surfactant-Associated Protein C: A pulmonary surfactant associated protein that plays a role in alveolar stability by lowering the surface tension at the air-liquid interface. It is a membrane-bound protein that constitutes 1-2% of the pulmonary surfactant mass. Pulmonary surfactant-associated protein C is one of the most hydrophobic peptides yet isolated and contains an alpha-helical domain with a central poly-valine segment that binds to phospholipid bilayers.Factor V: Heat- and storage-labile plasma glycoprotein which accelerates the conversion of prothrombin to thrombin in blood coagulation. Factor V accomplishes this by forming a complex with factor Xa, phospholipid, and calcium (prothrombinase complex). Deficiency of factor V leads to Owren's disease.Diamines: Organic chemicals which have two amino groups in an aliphatic chain.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)Ruthenium: A hard, brittle, grayish-white rare earth metal with an atomic symbol Ru, atomic number 44, and atomic weight 101.07. It is used as a catalyst and hardener for PLATINUM and PALLADIUM.Factor Va: Activated form of factor V. It is an essential cofactor for the activation of prothrombin catalyzed by factor Xa.Thrombin: An enzyme formed from PROTHROMBIN that converts FIBRINOGEN to FIBRIN.Liver: A large lobed glandular organ in the abdomen of vertebrates that is responsible for detoxification, metabolism, synthesis and storage of various substances.Blood Coagulation: The process of the interaction of BLOOD COAGULATION FACTORS that results in an insoluble FIBRIN clot.Electrophoresis, Polyacrylamide Gel: Electrophoresis in which a polyacrylamide gel is used as the diffusion medium.Rhodium: Rhodium. A hard and rare metal of the platinum group, atomic number 45, atomic weight 102.905, symbol Rh. (Dorland, 28th ed)Iridium: A metallic element with the atomic symbol Ir, atomic number 77, and atomic weight 192.22.Acetyl-CoA Hydrolase: An enzyme that catalyzes reversibly the hydrolysis of acetyl-CoA to yield CoA and acetate. The enzyme is involved in the oxidation of fatty acids. EC 3.1.2.1.Molecular Weight: The sum of the weight of all the atoms in a molecule.Hydrogenation: Addition of hydrogen to a compound, especially to an unsaturated fat or fatty acid. (From Stedman, 26th ed)Amination: The creation of an amine. It can be produced by the addition of an amino group to an organic compound or reduction of a nitro group.Substrate Specificity: A characteristic feature of enzyme activity in relation to the kind of substrate on which the enzyme or catalytic molecule reacts.Prothrombin: A plasma protein that is the inactive precursor of thrombin. It is converted to thrombin by a prothrombin activator complex consisting of factor Xa, factor V, phospholipid, and calcium ions. Deficiency of prothrombin leads to hypoprothrombinemia.Ornithine Decarboxylase: A pyridoxal-phosphate protein, believed to be the rate-limiting compound in the biosynthesis of polyamines. It catalyzes the decarboxylation of ornithine to form putrescine, which is then linked to a propylamine moiety of decarboxylated S-adenosylmethionine to form spermidine.Cyclization: Changing an open-chain hydrocarbon to a closed ring. (McGraw-Hill Dictionary of Scientific and Technical Terms, 5th ed)Acetyl-CoA C-Acyltransferase: Enzyme that catalyzes the final step of fatty acid oxidation in which ACETYL COA is released and the CoA ester of a fatty acid two carbons shorter is formed.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 Induction: An increase in the rate of synthesis of an enzyme due to the presence of an inducer which acts to derepress the gene responsible for enzyme synthesis.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.KetonesPhosphines: Inorganic or organic compounds derived from phosphine (PH3) by the replacement of H atoms. (From Grant & Hackh's Chemical Dictionary, 5th ed)Protein S Deficiency: An autosomal dominant disorder showing decreased levels of plasma protein S antigen or activity, associated with venous thrombosis and pulmonary embolism. PROTEIN S is a vitamin K-dependent plasma protein that inhibits blood clotting by serving as a cofactor for activated PROTEIN C (also a vitamin K-dependent protein), and the clinical manifestations of its deficiency are virtually identical to those of protein C deficiency. Treatment with heparin for acute thrombotic processes is usually followed by maintenance administration of coumarin drugs for the prevention of recurrent thrombosis. (From Harrison's Principles of Internal Medicine, 12th ed, p1511; Wintrobe's Clinical Hematology, 9th ed, p1523)Lesch-Nyhan Syndrome: An inherited disorder transmitted as a sex-linked trait and caused by a deficiency of an enzyme of purine metabolism; HYPOXANTHINE PHOSPHORIBOSYLTRANSFERASE. Affected individuals are normal in the first year of life and then develop psychomotor retardation, extrapyramidal movement disorders, progressive spasticity, and seizures. Self-destructive behaviors such as biting of fingers and lips are seen frequently. Intellectual impairment may also occur but is typically not severe. Elevation of uric acid in the serum leads to the development of renal calculi and gouty arthritis. (Menkes, Textbook of Child Neurology, 5th ed, pp127)Recombinant Proteins: Proteins prepared by recombinant DNA technology.Enzymes: Biological molecules that possess catalytic activity. They may occur naturally or be synthetically created. Enzymes are usually proteins, however CATALYTIC RNA and CATALYTIC DNA molecules have also been identified.Purine-Pyrimidine Metabolism, Inborn ErrorsRNA, 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.Enoyl-CoA Hydratase: An enzyme that catalyzes reversibly the hydration of unsaturated fatty acyl-CoA to yield beta-hydroxyacyl-CoA. It plays a role in the oxidation of fatty acids and in mitochondrial fatty acid synthesis, has broad specificity, and is most active with crotonyl-CoA. EC 4.2.1.17.Progesterone Reductase: An enzyme that catalyzes the reduction of a 3 beta-hydroxy-delta(5)-steroid to 3-oxo-delta(4)-steroid in the presence of NAD. It converts pregnenolone to progesterone and dehydroepiandrosterone to androstenedione. EC 1.1.1.145.Binding Sites: The parts of a macromolecule that directly participate in its specific combination with another molecule.Organometallic Compounds: A class of compounds of the type R-M, where a C atom is joined directly to any other element except H, C, N, O, F, Cl, Br, I, or At. (Grant & Hackh's Chemical Dictionary, 5th ed)Chemistry, Organic: The study of the structure, preparation, properties, and reactions of carbon compounds. (McGraw-Hill Dictionary of Scientific and Technical Terms, 6th ed)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).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.Receptors, Thrombin: A family of proteinase-activated receptors that are specific for THROMBIN. They are found primarily on PLATELETS and on ENDOTHELIAL CELLS. Activation of thrombin receptors occurs through the proteolytic action of THROMBIN, which cleaves the N-terminal peptide from the receptor to reveal a new N-terminal peptide that is a cryptic ligand for the receptor. The receptors signal through HETEROTRIMERIC GTP-BINDING PROTEINS. Small synthetic peptides that contain the unmasked N-terminal peptide sequence can also activate the receptor in the absence of proteolytic activity.Enzyme Activation: Conversion of an inactive form of an enzyme to one possessing metabolic activity. It includes 1, activation by ions (activators); 2, activation by cofactors (coenzymes); and 3, conversion of an enzyme precursor (proenzyme or zymogen) to an active enzyme.Lewis Acids: Any chemical species which accepts an electron-pair from a LEWIS BASE in a chemical bonding reaction.Thrombophilia: A disorder of HEMOSTASIS in which there is a tendency for the occurrence of THROMBOSIS.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)Carboxy-Lyases: Enzymes that catalyze the addition of a carboxyl group to a compound (carboxylases) or the removal of a carboxyl group from a compound (decarboxylases). EC 4.1.1.Cycloheximide: Antibiotic substance isolated from streptomycin-producing strains of Streptomyces griseus. It acts by inhibiting elongation during protein synthesis.Receptors, Cell Surface: Cell surface proteins that bind signalling molecules external to the cell with high affinity and convert this extracellular event into one or more intracellular signals that alter the behavior of the target cell (From Alberts, Molecular Biology of the Cell, 2nd ed, pp693-5). Cell surface receptors, unlike enzymes, do not chemically alter their ligands.Blood Coagulation Disorders: Hemorrhagic and thrombotic disorders that occur as a consequence of abnormalities in blood coagulation due to a variety of factors such as COAGULATION PROTEIN DISORDERS; BLOOD PLATELET DISORDERS; BLOOD PROTEIN DISORDERS or nutritional conditions.Recycling: The extraction and recovery of usable or valuable material from scrap or other discarded materials. (from McGraw-Hill Dictionary of Scientific and Technical Terms, 6th ed.)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.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.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)Alcohols: Alkyl compounds containing a hydroxyl group. They are classified according to relation of the carbon atom: primary alcohols, R-CH2OH; secondary alcohols, R2-CHOH; tertiary alcohols, R3-COH. (From Grant & Hackh's Chemical Dictionary, 5th ed)Alkynes: Hydrocarbons with at least one triple bond in the linear portion, of the general formula Cn-H2n-2.Isoenzymes: Structurally related forms of an enzyme. Each isoenzyme has the same mechanism and classification, but differs in its chemical, physical, or immunological characteristics.Partial Thromboplastin Time: The time required for the appearance of FIBRIN strands following the mixing of PLASMA with phospholipid platelet substitute (e.g., crude cephalins, soybean phosphatides). It is a test of the intrinsic pathway (factors VIII, IX, XI, and XII) and the common pathway (fibrinogen, prothrombin, factors V and X) of BLOOD COAGULATION. It is used as a screening test and to monitor HEPARIN therapy.beta-N-Acetylhexosaminidases: A hexosaminidase specific for non-reducing N-acetyl-D-hexosamine residues in N-acetyl-beta-D-hexosaminides. It acts on GLUCOSIDES; GALACTOSIDES; and several OLIGOSACCHARIDES. Two specific mammalian isoenzymes of beta-N-acetylhexoaminidase are referred to as HEXOSAMINIDASE A and HEXOSAMINIDASE B. Deficiency of the type A isoenzyme causes TAY-SACHS DISEASE, while deficiency of both A and B isozymes causes SANDHOFF DISEASE. The enzyme has also been used as a tumor marker to distinguish between malignant and benign disease.Rats, Inbred Strains: Genetically identical individuals developed from brother and sister matings which have been carried out for twenty or more generations or by parent x offspring matings carried out with certain restrictions. This also includes animals with a long history of closed colony breeding.IminesMicrosomes, Liver: Closed vesicles of fragmented endoplasmic reticulum created when liver cells or tissue are disrupted by homogenization. They may be smooth or rough.3-Hydroxyacyl CoA Dehydrogenases: Enzymes that reversibly catalyze the oxidation of a 3-hydroxyacyl CoA to 3-ketoacyl CoA in the presence of NAD. They are key enzymes in the oxidation of fatty acids and in mitochondrial fatty acid synthesis.Receptor, PAR-1: A thrombin receptor subtype that couples to HETEROTRIMERIC GTP-BINDING PROTEINS resulting in the activation of a variety of signaling mechanisms including decreased intracellular CYCLIC AMP, increased TYPE C PHOSPHOLIPASES and increased PHOSPHOLIPASE A2.Factor Xa: Activated form of factor X that participates in both the intrinsic and extrinsic pathways of blood coagulation. It catalyzes the conversion of prothrombin to thrombin in conjunction with other cofactors.Immunodiffusion: Technique involving the diffusion of antigen or antibody through a semisolid medium, usually agar or agarose gel, with the result being a precipitin reaction.Anticoagulants: Agents that prevent clotting.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.Metalloporphyrins: Porphyrins which are combined with a metal ion. The metal is bound equally to all four nitrogen atoms of the pyrrole rings. They possess characteristic absorption spectra which can be utilized for identification or quantitative estimation of porphyrins and porphyrin-bound compounds.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.Chromatography, Gel: Chromatography on non-ionic gels without regard to the mechanism of solute discrimination.1-Carboxyglutamic Acid: Found in various tissues, particularly in four blood-clotting proteins including prothrombin, in kidney protein, in bone protein, and in the protein present in various ectopic calcifications.Glucosidases: Enzymes that hydrolyze O-glucosyl-compounds. (Enzyme Nomenclature, 1992) EC 3.2.1.-.Procollagen-Proline Dioxygenase: A mixed-function oxygenase that catalyzes the hydroxylation of a prolyl-glycyl containing peptide, usually in PROTOCOLLAGEN, to a hydroxyprolylglycyl-containing-peptide. The enzyme utilizes molecular OXYGEN with a concomitant oxidative decarboxylation of 2-oxoglutarate to SUCCINATE. The enzyme occurs as a tetramer of two alpha and two beta subunits. The beta subunit of procollagen-proline dioxygenase is identical to the enzyme PROTEIN DISULFIDE-ISOMERASES.Cinchona Alkaloids: Alkaloids extracted from various species of Cinchona.Blood Coagulation Tests: Laboratory tests for evaluating the individual's clotting mechanism.Immunoelectrophoresis: A technique that combines protein electrophoresis and double immunodiffusion. In this procedure proteins are first separated by gel electrophoresis (usually agarose), then made visible by immunodiffusion of specific antibodies. A distinct elliptical precipitin arc results for each protein detectable by the antisera.Hydroxymethylglutaryl CoA Reductases: Enzymes that catalyze the reversible reduction of alpha-carboxyl group of 3-hydroxy-3-methylglutaryl-coenzyme A to yield MEVALONIC ACID.Immunosorbent Techniques: Techniques for removal by adsorption and subsequent elution of a specific antibody or antigen using an immunosorbent containing the homologous antigen or antibody.Glycoproteins: Conjugated protein-carbohydrate compounds including mucins, mucoid, and amyloid glycoproteins.Disseminated Intravascular Coagulation: A disorder characterized by procoagulant substances entering the general circulation causing a systemic thrombotic process. The activation of the clotting mechanism may arise from any of a number of disorders. A majority of the patients manifest skin lesions, sometimes leading to PURPURA FULMINANS.Models, Molecular: Models used experimentally or theoretically to study molecular shape, electronic properties, or interactions; includes analogous molecules, computer-generated graphics, and mechanical structures.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.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).Antithrombin III: A plasma alpha 2 glycoprotein that accounts for the major antithrombin activity of normal plasma and also inhibits several other enzymes. It is a member of the serpin superfamily.Biocatalysis: The facilitation of biochemical reactions with the aid of naturally occurring catalysts such as ENZYMES.Alkadienes: Acyclic branched or unbranched hydrocarbons having two carbon-carbon double bonds.Immune Sera: Serum that contains antibodies. It is obtained from an animal that has been immunized either by ANTIGEN injection or infection with microorganisms containing the antigen.Thrombosis: Formation and development of a thrombus or blood clot in the blood vessel.Thrombophlebitis: Inflammation of a vein associated with a blood clot (THROMBUS).Immunoassay: A technique using antibodies for identifying or quantifying a substance. Usually the substance being studied serves as antigen both in antibody production and in measurement of antibody by the test substance.Factor V Deficiency: A deficiency of blood coagulation factor V (known as proaccelerin or accelerator globulin or labile factor) leading to a rare hemorrhagic tendency known as Owren's disease or parahemophilia. It varies greatly in severity. Factor V deficiency is an autosomal recessive trait. (Dorland, 27th ed)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.Aldehydes: Organic compounds containing a carbonyl group in the form -CHO.Glucose-6-Phosphatase: An enzyme that catalyzes the conversion of D-glucose 6-phosphate and water to D-glucose and orthophosphate. EC 3.1.3.9.Gene Expression Regulation, Enzymologic: Any of the processes by which nuclear, cytoplasmic, or intercellular factors influence the differential control of gene action in enzyme synthesis.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.Factor X: Storage-stable glycoprotein blood coagulation factor that can be activated to factor Xa by both the intrinsic and extrinsic pathways. A deficiency of factor X, sometimes called Stuart-Prower factor deficiency, may lead to a systemic coagulation disorder.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.Dactinomycin: A compound composed of a two CYCLIC PEPTIDES attached to a phenoxazine that is derived from STREPTOMYCES parvullus. It binds to DNA and inhibits RNA synthesis (transcription), with chain elongation more sensitive than initiation, termination, or release. As a result of impaired mRNA production, protein synthesis also declines after dactinomycin therapy. (From AMA Drug Evaluations Annual, 1993, p2015)Amines: A group of compounds derived from ammonia by substituting organic radicals for the hydrogens. (From Grant & Hackh's Chemical Dictionary, 5th ed)Alcohol Oxidoreductases: A subclass of enzymes which includes all dehydrogenases acting on primary and secondary alcohols as well as hemiacetals. They are further classified according to the acceptor which can be NAD+ or NADP+ (subclass 1.1.1), cytochrome (1.1.2), oxygen (1.1.3), quinone (1.1.5), or another acceptor (1.1.99).Blotting, Western: Identification of proteins or peptides that have been electrophoretically separated by blot transferring from the electrophoresis gel to strips of nitrocellulose paper, followed by labeling with antibody probes.Microsomes: Artifactual vesicles formed from the endoplasmic reticulum when cells are disrupted. They are isolated by differential centrifugation and are composed of three structural features: rough vesicles, smooth vesicles, and ribosomes. Numerous enzyme activities are associated with the microsomal fraction. (Glick, Glossary of Biochemistry and Molecular Biology, 1990; from Rieger et al., Glossary of Genetics: Classical and Molecular, 5th ed)Hydrolysis: The process of cleaving a chemical compound by the addition of a molecule of water.Organic Chemistry Processes: The reactions, changes in structure and composition, the properties of the reactions of carbon compounds, and the associated energy changes.Eflornithine: An inhibitor of ORNITHINE DECARBOXYLASE, the rate limiting enzyme of the polyamine biosynthetic pathway.AmidohydrolasesIsoelectric Point: The pH in solutions of proteins and related compounds at which the dipolar ions are at a maximum.Antithrombins: Endogenous factors and drugs that directly inhibit the action of THROMBIN, usually by blocking its enzymatic activity. They are distinguished from INDIRECT THROMBIN INHIBITORS, such as HEPARIN, which act by enhancing the inhibitory effects of antithrombins.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).Hemostasis: The process which spontaneously arrests the flow of BLOOD from vessels carrying blood under pressure. It is accomplished by contraction of the vessels, adhesion and aggregation of formed blood elements (eg. ERYTHROCYTE AGGREGATION), and the process of BLOOD COAGULATION.Sepsis: Systemic inflammatory response syndrome with a proven or suspected infectious etiology. When sepsis is associated with organ dysfunction distant from the site of infection, it is called severe sepsis. When sepsis is accompanied by HYPOTENSION despite adequate fluid infusion, it is called SEPTIC SHOCK.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.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.Factor VIIIa: Activated form of factor VIII. The B-domain of factor VIII is proteolytically cleaved by thrombin to form factor VIIIa. Factor VIIIa exists as a non-covalent dimer in a metal-linked (probably calcium) complex and functions as a cofactor in the enzymatic activation of factor X by factor IXa. Factor VIIIa is similar in structure and generation to factor Va.Glucosephosphate DehydrogenaseImmunochemistry: Field of chemistry that pertains to immunological phenomena and the study of chemical reactions related to antigen stimulation of tissues. It includes physicochemical interactions between antigens and antibodies.Time Factors: Elements of limited time intervals, contributing to particular results or situations.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.Purpura Fulminans: A severe, rapidly fatal reaction occurring most commonly in children following an infectious illness. It is characterized by large, rapidly spreading skin hemorrhages, fever, or shock. Purpura fulminans often accompanies or is triggered by DISSEMINATED INTRAVASCULAR COAGULATION.Antithrombin III Deficiency: An absence or reduced level of Antithrombin III leading to an increased risk for thrombosis.Hot Temperature: Presence of warmth or heat or a temperature notably higher than an accustomed norm.Half-Life: The time it takes for a substance (drug, radioactive nuclide, or other) to lose half of its pharmacologic, physiologic, or radiologic activity.Cytosol: Intracellular fluid from the cytoplasm after removal of ORGANELLES and other insoluble cytoplasmic components.Immunoblotting: Immunologic method used for detecting or quantifying immunoreactive substances. The substance is identified by first immobilizing it by blotting onto a membrane and then tagging it with labeled antibodies.EstersDrug Stability: The chemical and physical integrity of a pharmaceutical product.Multienzyme Complexes: Systems of enzymes which function sequentially by catalyzing consecutive reactions linked by common metabolic intermediates. They may involve simply a transfer of water molecules or hydrogen atoms and may be associated with large supramolecular structures such as MITOCHONDRIA or RIBOSOMES.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.Combinatorial Chemistry Techniques: A technology, in which sets of reactions for solution or solid-phase synthesis, is used to create molecular libraries for analysis of compounds on a large scale.Spectrometry, Fluorescence: Measurement of the intensity and quality of fluorescence.Leucine: An essential branched-chain amino acid important for hemoglobin formation.Transition Elements: Elements with partially filled d orbitals. They constitute groups 3-12 of the periodic table of elements.Cycloparaffins: Alicyclic hydrocarbons in which three or more of the carbon atoms in each molecule are united in a ring structure and each of the ring carbon atoms is joined to two hydrogen atoms or alkyl groups. The simplest members are cyclopropane (C3H6), cyclobutane (C4H8), cyclohexane (C6H12), and derivatives of these such as methylcyclohexane (C6H11CH3). (From Sax, et al., Hawley's Condensed Chemical Dictionary, 11th ed)Cross Reactions: Serological reactions in which an antiserum against one antigen reacts with a non-identical but closely related antigen.Gene Expression: The phenotypic manifestation of a gene or genes by the processes of GENETIC TRANSCRIPTION and GENETIC TRANSLATION.Allyl CompoundsAntibodies, Catalytic: Antibodies that can catalyze a wide variety of chemical reactions. They are characterized by high substrate specificity and share many mechanistic features with enzymes.Zeolites: Zeolites. A group of crystalline, hydrated alkali-aluminum silicates. They occur naturally in sedimentary and volcanic rocks, altered basalts, ores, and clay deposits. Some 40 known zeolite minerals and a great number of synthetic zeolites are available commercially. (From Merck Index, 11th ed)Platinum: Platinum. A heavy, soft, whitish metal, resembling tin, atomic number 78, atomic weight 195.09, symbol Pt. (From Dorland, 28th ed) It is used in manufacturing equipment for laboratory and industrial use. It occurs as a black powder (platinum black) and as a spongy substance (spongy platinum) and may have been known in Pliny's time as "alutiae".Hydrogen: The first chemical element in the periodic table. It has the atomic symbol H, atomic number 1, and atomic weight [1.00784; 1.00811]. It exists, under normal conditions, as a colorless, odorless, tasteless, diatomic gas. Hydrogen ions are PROTONS. Besides the common H1 isotope, hydrogen exists as the stable isotope DEUTERIUM and the unstable, radioactive isotope TRITIUM.Fibrinolysis: The natural enzymatic dissolution of FIBRIN.Thromboplastin: Constituent composed of protein and phospholipid that is widely distributed in many tissues. It serves as a cofactor with factor VIIa to activate factor X in the extrinsic pathway of blood coagulation.Chromatography, DEAE-Cellulose: A type of ion exchange chromatography using diethylaminoethyl cellulose (DEAE-CELLULOSE) as a positively charged resin. (From McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)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)Methane: The simplest saturated hydrocarbon. It is a colorless, flammable gas, slightly soluble in water. It is one of the chief constituents of natural gas and is formed in the decomposition of organic matter. (Grant & Hackh's Chemical Dictionary, 5th ed)Organic Chemistry Phenomena: The conformation, properties, reaction processes, and the properties of the reactions of carbon compounds.Peroxynitrous Acid: A potent oxidant synthesized by the cell during its normal metabolism. Peroxynitrite is formed from the reaction of two free radicals, NITRIC OXIDE and the superoxide anion (SUPEROXIDES).Halogens: A family of nonmetallic, generally electronegative, elements that form group 17 (formerly group VIIa) of the periodic table.Phosphotransferases: A rather large group of enzymes comprising not only those transferring phosphate but also diphosphate, nucleotidyl residues, and others. These have also been subdivided according to the acceptor group. (From Enzyme Nomenclature, 1992) EC 2.7.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.Kidney: Body organ that filters blood for the secretion of URINE and that regulates ion concentrations.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.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.Halogenation: Covalent attachment of HALOGENS to other compounds.Factor VIIa: Activated form of factor VII. Factor VIIa activates factor X in the extrinsic pathway of blood coagulation.Carrier Proteins: Transport proteins that carry specific substances in the blood or across cell membranes.Green Chemistry Technology: Pollution prevention through the design of effective chemical products that have low or no toxicity and use of chemical processes that reduce or eliminate the use and generation of hazardous substances.Proteolipids: Protein-lipid combinations abundant in brain tissue, but also present in a wide variety of animal and plant tissues. In contrast to lipoproteins, they are insoluble in water, but soluble in a chloroform-methanol mixture. The protein moiety has a high content of hydrophobic amino acids. The associated lipids consist of a mixture of GLYCEROPHOSPHATES; CEREBROSIDES; and SULFOGLYCOSPHINGOLIPIDS; while lipoproteins contain PHOSPHOLIPIDS; CHOLESTEROL; and TRIGLYCERIDES.Vitamin K: A lipid cofactor that is required for normal blood clotting. Several forms of vitamin K have been identified: VITAMIN K 1 (phytomenadione) derived from plants, VITAMIN K 2 (menaquinone) from bacteria, and synthetic naphthoquinone provitamins, VITAMIN K 3 (menadione). Vitamin K 3 provitamins, after being alkylated in vivo, exhibit the antifibrinolytic activity of vitamin K. Green leafy vegetables, liver, cheese, butter, and egg yolk are good sources of vitamin K.Heterocyclic Compounds: Ring compounds having atoms other than carbon in their nuclei. (Grant & Hackh's Chemical Dictionary, 5th ed)Spectrophotometry: The art or process of comparing photometrically the relative intensities of the light in different parts of the spectrum.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.Epoxy Compounds: Organic compounds that include a cyclic ether with three ring atoms in their structure. They are commonly used as precursors for POLYMERS such as EPOXY RESINS.Silicon Dioxide: Transparent, tasteless crystals found in nature as agate, amethyst, chalcedony, cristobalite, flint, sand, QUARTZ, and tridymite. The compound is insoluble in water or acids except hydrofluoric acid.Venous Thrombosis: The formation or presence of a blood clot (THROMBUS) within a vein.Blood Coagulation Factor Inhibitors: Substances, usually endogenous, that act as inhibitors of blood coagulation. They may affect one or multiple enzymes throughout the process. As a group, they also inhibit enzymes involved in processes other than blood coagulation, such as those from the complement system, fibrinolytic enzyme system, blood cells, and bacteria.Microwaves: That portion of the electromagnetic spectrum from the UHF (ultrahigh frequency) radio waves and extending into the INFRARED RAYS frequencies.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.Boranes: The collective name for the boron hydrides, which are analogous to the alkanes and silanes. Numerous boranes are known. Some have high calorific values and are used in high-energy fuels. (From Grant & Hackh's Chemical Dictionary, 5th ed)Naphthols: Naphthalene derivatives carrying one or more hydroxyl (-OH) groups at any ring position. They are often used in dyes and pigments, as antioxidants for rubber, fats, and oils, as insecticides, in pharmaceuticals, and in numerous other applications.Fibroblasts: Connective tissue cells which secrete an extracellular matrix rich in collagen and other macromolecules.Coagulation Protein Disorders: Hemorrhagic and thrombotic disorders resulting from abnormalities or deficiencies of coagulation proteins.Coordination Complexes: Neutral or negatively charged ligands bonded to metal cations or neutral atoms. The number of ligand atoms to which the metal center is directly bonded is the metal cation's coordination number, and this number is always greater than the regular valence or oxidation number of the metal. A coordination complex can be negative, neutral, or positively charged.Pulmonary Surfactants: Substances and drugs that lower the SURFACE TENSION of the mucoid layer lining the PULMONARY ALVEOLI.Solvents: Liquids that dissolve other substances (solutes), generally solids, without any change in chemical composition, as, water containing sugar. (Grant & Hackh's Chemical Dictionary, 5th ed)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).Factor VII: Heat- and storage-stable plasma protein that is activated by tissue thromboplastin to form factor VIIa in the extrinsic pathway of blood coagulation. The activated form then catalyzes the activation of factor X to factor Xa.Adenosine Triphosphate: An adenine nucleotide containing three phosphate groups esterified to the sugar moiety. In addition to its crucial roles in metabolism adenosine triphosphate is a neurotransmitter.Crystallography, X-Ray: The study of crystal structure using X-RAY DIFFRACTION techniques. (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)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).
enzyme - a protein that promotes a cellular process, much like a catalyst in an ordinary chemical reaction ... such as hemoglobin or other cellular proteins or enzymes of red blood cells. These alterations generally protect red blood ... All proteins, including enzymes, have to last for the entire lifetime of the red blood cell, which is normally 120 days. ... receptor (cellular surface) - specialized integral membrane proteins that take part in communication between the cell and the ...
Enzymes, proteins, and other biologically and chemically active substances have been immobilized on magnetic nanoparticles. ... Magnetic nanoparticles are of potential use as a catalyst or catalyst supports. In chemistry, a catalyst support is the ... This technology is potentially relevant to cellular labelling/cell separation, detoxification of biological fluids, tissue ... The resulting catalyst was then used for the chemoselective oxidation of primary and secondary alcohols. The catalytic reaction ...
On top of this, temperature also determines the degree to which enzymes can act as catalysts. With this in mind, we can ... found that red blood cells of the newt not only produce hemoglobin, but also ferritin, ribosomal proteins, and proteins assumed ... The cellular (myocyte) membrane will alter its permeability as adulthood is reached, adrenergenic/cholinergic systems will ... While the activity of this enzyme varies across seasons and the mating habits of the newt, the exact role this enzyme plays is ...
Enzymes are biological catalysts whose function is affected by a variety of factors including temperature, which, at different ... Cellular products are biodegradable and therefore can be considered environmentally friendly. The oxygen deployed in aerobic ... genetic expression and protein production. Despite this fundamental knowledge on cell physiology, a solid understanding on ... Such complexity is increased by the interplay with the environment, the later playing a crucial role by affecting cellular ...
The third most common mutation is 452G>A. This nonsense mutation causes protein termination, such that the enzyme DHCR7 would ... catalyst of the rate-limiting step). It involves a feedback loop that is sensitive to cellular levels of cholesterol. The four ... Their involvement in regulation stems mostly from their association with proteins; upon binding substrates, some proteins have ... The synthesis of the enzyme HMG-CoA reductase is controlled by sterol regulatory element binding protein (SREBP). This is a ...
... possibly facilitated by enzymes or other molecular catalysts, to generate output physical entities (products). Reactions ... transport events that direct molecules between cellular compartments, and events such as the activation of a protein by ... Entities (nucleic acids, proteins, complexes and small molecules) participating in reactions form a network of biological ... Physical entities can be small molecules like glucose or ATP, or large molecules like DNA, RNA, and proteins, encoded directly ...
... followed by replacement of many cellular ribozyme catalysts by protein-based enzymes. Proteins are much more flexible in ... For instance, recent studies of transfer RNAs, the enzymes that charge them with amino acids (the first step in protein ... According to this hypothesis, the ancient RNA world transitioned into the modern cellular world via the evolution of protein ... If the freely floating molecules that code for enzymes are not enclosed in cells, the enzymes will automatically benefit the ...
2.2 Purified enzyme-based. *3 Uses *3.1 Protein synthesis. *3.2 Metabolic manipulation ... In vitro biosystems can implement some biological reactions that living microbes or chemical catalysts cannot implement before ... Enzymatic systems, without the barrier of cellular membrane, usually have faster reaction rates than microbial systems. For ... Protein synthesisEdit. Main article: Cell-free protein synthesis. In vitro biosystems can be easily controlled and accessed ...
... cellular location and detailed information about the enzymes catalysing the reactions. The data stored in SABIO-RK in a ... EC enzyme classification, protein complex composition, wild type / mutant information), kinetic parameters together with ... This includes reactions, their participants (substrates, products), modifiers (inhibitors, activators, cofactors), catalyst ... 2010). "Enzyme kinetics informatics: From instrument to browser". FEBS Journal. 277 (18): 3769-79. doi:10.1111/j.1742-4658.2010 ...
... is a 538-residue, 61-kDa protein. In solution, a number of homologues exist as homodimers. The enzyme ... Poor CB, Andorfer MC, Lewis JC (June 2014). "Improving the stability and catalyst lifetime of the halogenase RebH by directed ... Tryptophan 7-halogenase at the US National Library of Medicine Medical Subject Headings (MeSH) Molecular and Cellular Biology ... Following design of a suitable enzyme, a cross-linked enzyme aggregate is used for larger-scale reaction. The enzyme by itself ...
Although proteins are the most common components of cellular enzymatic activity, nucleic acids are also used in the cell to ... Aside being used as extensions to template DNA strands, XNA activity has been tested for use as genetic catalysts. ... could be used to cleave RNA during post-transcriptional RNA processing acting as XNA enzymes, hence the name XNAzymes. FANA ... XNA, novel proteins, etc. might represent novel toxins, or have an allergic potential that needs to be assessed. Xenobiology ...
... and the catalysts are naturally occurring macromolecular substances known as enzymes. Enzymes possess specific binding sites ... See also the cellular component term 'cellular component unknown' (below). "Used for the annotation of gene products whose ... Ligase is the systematic name for any enzyme of EC class 6." "Modulates the activity of an enzyme." exact_synonym: "enzyme ... "Interacting selectively with any protein or protein complex (a complex of two or more proteins that may include other ...
Not all biological catalysts are protein enzymes; RNA-based catalysts such as ribozymes and ribosomes are essential to many ... Some other examples of enzymes are phosphofructokinase and hexokinase, both of which are important for cellular respiration ( ... Enzymes are usually protein molecules that manipulate other molecules - the enzymes' substrates. These target molecules bind to ... ISBN 0-471-30309-7. Fersht, Alan (1999). Structure and mechanism in protein science: a guide to enzyme catalysis and protein ...
Proteins are made of amino acids arranged in a linear chain joined together by peptide bonds. Many proteins are enzymes that ... Enzymes act as catalysts that allow the reactions to proceed more rapidly. Enzymes also allow the regulation of metabolic ... by cellular respiration, and anabolism, the building up of components of cells such as proteins and nucleic acids. Usually, ... Several common classes of enzymes digest these polymers. These digestive enzymes include proteases that digest proteins into ...
... a ribonucleic acid that acts as a catalyst in the same way that a protein based enzyme would. Its function is to cleave off an ... Cellular RNase Ps are ribonucleoproteins (RNP). RNA from bacterial RNase Ps retains its catalytic activity in the absence of ... The primary role of the C5 protein is to enhance the substrate binding affinity and the catalytic rate of the M1 RNA enzyme ... Bacterial RNase P has two components: an RNA chain, called M1 RNA, and a polypeptide chain, or protein, called C5 protein. In ...
Before the discovery of ribozymes, enzymes, which are defined as catalytic proteins, were the only known biological catalysts. ... a tethered ribosome that works nearly as well as the authentic cellular component that produces all the proteins and enzymes ... Like many protein enzymes metal binding is also critical to the function of many ribozymes. Often these interactions use both ... like protein enzymes), and contributed to the RNA world hypothesis, which suggests that RNA may have been important in the ...
Like DNA, RNA can store and replicate genetic information; like protein enzymes, RNA enzymes (ribozymes) can catalyze (start or ... RNAs are known to play roles in other cellular catalytic processes, specifically in the targeting of enzymes to specific RNA ... from small catalysts to long RNA based enzymes. Particular RNAs were amplified up to 10,000 times, a first RNA version of the ... RNA as an enzyme[edit]. Further information: Ribozyme. RNA enzymes, or ribozymes, are found in today's DNA-based life and could ...
enzyme Enzymes are biological molecules (proteins) that act as catalysts and help complex reactions occur everywhere in life. ... the major source of energy for cellular reactions. The chemical formula for ATP is C10H16N5O13P3. adenylate cyclase An enzyme ... In biocatalytic processes, natural catalysts, such as protein enzymes, perform chemical transformations on organic compounds. ... lipoprotein a biochemical assembly that contains both proteins and lipids, bound to the proteins, which allow fats to move ...
... however metal independent enzymes exist. Glycosyltransferases can be segregated into "retaining" or "inverting" enzymes ... Sequence-based classification methods have proven to be a powerful way of generating hypotheses for protein function based on ... "Glycosyltransferase structural biology and its role in the design of catalysts for glycosylation". Current Opinion in ... Molecular and Cellular Biology portal. ... The carbohydrate-active enzyme database presents a sequence- ...
... which stimulates protein synthesis and cellular growth, and inhibits apoptosis. Ras is a G protein, or a guanosine-nucleotide- ... Because enzyme catalysis in general is achieved by lowering the energy barrier between substrate and product, mutation of Q61 ... Ras requires a GAP for inactivation as it is a relatively poor catalyst on its own, as opposed to other G-domain-containing ... All Ras protein family members belong to a class of protein called small GTPase, and are involved in transmitting signals ...
Feathers have similar keratins and are extremely resistant to protein digestive enzymes. The stiffness of hair and feather is ... usually proteins secreted to the extracellular medium.[2] Since most cellular compartments are reducing environments, in ... proteins which have cysteine residues in proximity to each other that function as oxidation sensors or redox catalysts; when ... The in vivo oxidation and reduction of protein disulfide bonds by thiol-disulfide exchange is facilitated by a protein called ...
... in cellular oxidant status can be sensed by specific proteins which regulate a set of genes encoding antioxidant enzymes. Such ... These enzymes act on duplex DNA and clean up DNA 3' terminal ends. Prokaryotic cells contain catalysts that modify the primary ... The genes include many genes coding for metabolic enzymes and antioxidant enzymes demonstrating the role of these enzymes in ... Secondary defenses include DNA-repair systems, proteolytic and lipolytic enzymes. DNA repair enzymes include endonuclease IV, ...
Feathers have similar keratins and are extremely resistant to protein digestive enzymes. Different parts of the hair and ... usually proteins secreted to the extracellular medium. Since most cellular compartments are reducing environments, in general, ... proteins which have cysteine residues in proximity to each other that function as oxidation sensors or redox catalysts; when ... The native form of a protein is usually a single disulfide species, although some proteins may cycle between a few disulfide ...
... to tether cellular proteins to a ubiquitin ligase, resulting in ubiquitination and degradation of the tethered protein.[23] ... protein exchange catalyst' that equilibrates F-box subunits of SCF ubiquitin ligases with the cullin scaffold subunit.[17] ... CSN plays a key role in regulating SCF and other CRL enzymes by removing the ubiquitin-like protein NEDD8 from their cullin ... Effects on protein synthesis. Plant Physiol. 74, 956-961 *^ Stirling, C.J., Rothblatt, J., Hosobuchi, M., Deshaies, R., and ...
Carbonyl reductase 1, also known as CBR1, is an enzyme which in humans is encoded by the CBR1 gene. The protein encoded by this ... Therefore, CBR1 may play a beneficial role in protecting against cellular damage resulting from oxidative stress. Up-to-date ... indicating that CBR1 may play an important role as an oxidation-reduction catalyst in biological processes. CBR1 has been ... The enzyme consists of 277 amino acid residues and is widely distributed in human tissues such as liver, epidermis, stomach, ...
Required for many proteins and enzymes, notably hemoglobin to prevent anemia Meat, seafood, nuts, beans, dark chocolate[23] ... Possibly important to basement membrane architecture and tissue development, as a needed catalyst to make collagen IV.[37] ... Needed for production of hydrochloric acid in the stomach and in cellular pump functions Table salt (sodium chloride) is the ... A cofactor in enzyme functions Grains, legumes, seeds, nuts, leafy vegetables, tea, coffee[25] manganese deficiency manganism ...
Study Protein Structure Unit 3 flashcards from Sebastian Ostrowski ... What is the function and what are the Example of ENZYMES ? Catalysts of cellular reactions TRYPSIN ... Protein Structure Unit 3 Flashcards Preview Biochem , Protein Structure Unit 3 , Flashcards ... Hold proteins together that interact in catalytic or signaling pathways CHAPRONES Hsp70. ...
Functions of proteins to include structural, enzymes, hormones, antibodies.. *Enzymes function as biological catalysts and are ... They speed up cellular reactions and are unchanged in the process. *The shape of the active site of enzyme molecules is ... Each enzyme works best in its optimum conditions. *Enzymes and other proteins can be affected by temperature and pH, which ... This energy can be used for cellular activities including muscle cell contraction, cell division, protein synthesis and ...
Reusable (since they dont participate). Enzymes! Organization: Biological catalysts.. Proteins and some RNA molecules ( ... Explain how enzymes function as catalysts.. Explain the induced fit model of enzyme function.. Provide examples of enzyme- ... Reactants Enzyme-Substrate. Complex Enzyme Products Examples: The active site is localized to a small area of the enzyme ... Like all proteins, enzyme structure (and therefore function) can be effected by the conditions of the enzymes enviornment. ...
Catalysts may be classified generally according to their physical state, their chemical nature, or the nature of the reactions ... enzymes (in protein: Enzymes) (in protein: The nature of catalysis) *ion exchangers (in ion-exchange reaction: In industry and ... cellular interactions (in nutrition) *drug interaction (in drug: Receptors) *hydrogen production (in hydrogen (H): Production ... Catalysts may be gases, liquids, or solids. In homogeneous catalysis, the catalyst is molecularly dispersed in the same phase ( ...
enzyme - a protein that promotes a cellular process, much like a catalyst in an ordinary chemical reaction ... such as hemoglobin or other cellular proteins or enzymes of red blood cells. These alterations generally protect red blood ... All proteins, including enzymes, have to last for the entire lifetime of the red blood cell, which is normally 120 days. ... receptor (cellular surface) - specialized integral membrane proteins that take part in communication between the cell and the ...
Nature and properties of enzymes as biological catalysts. The concept of metabolic pathway. Bioenergetics (general remarks) and ... From genes to proteins: transcription, processing of RNAs, and translation.. Energy and metabolism. Matter and energy flux ... Unicellular and multi-cellular organisms. General aspects of bacteria and viruses and their interactions with eukaryotic cells ... Structure and function of biological macromolecules: carbohydrates, lipids, proteins, and nucleic acids. The DNA as the ...
What are enzymes? Enzymes are proteins that convert chemicals or act as catalysts. Certain enzymes in plants, for example, can ... assist in the absorption of carbon dioxide molecules and incorporate them into other cellular molecules. ... Enzymes are proteins that help break down other molecules or build new ones. Several enzymes can work in concert to convert ... What are proteins? A Protein is a chain of amino acids that folds in a particular structure necessary for the function of that ...
Make research projects and school reports about enzyme easy with credible articles from our FREE, online encyclopedia and ... enzyme A protein that acts as a catalyst in biochemical reactions. Each enzyme is specific to a particular reaction or group of ... Enzymes are present in all living organisms, and through their high degree of specificity exert close control over cellular ... Enzyme UXL Encyclopedia of Science COPYRIGHT 2002 The Gale Group, Inc.. Enzyme. An enzyme is a biological catalyst. A catalyst ...
Free flashcards to help memorize facts about Vocabulary for Proteins & Amino Acids. Other activities to help include hangman, ... Enzymes chemical catalysts which promote and regulate almost all chemical reactions occurring on the cellular level ... Proteins. Vocabulary for Proteins & Amino Acids. Term. Definition. Proteins. large molecules required in the diet to help form ... Complete Proteins. food that contains all the indispensable amino acids Incomplete Proteins. protein that is lacking one or ...
... enzymes,by,3,000,percent,biological,biology news articles,biology news today,latest biology news,current biology news,biology ... Light of specific wavelengths can be used to boost an enzymes functio...In a paper published in The Journal of Physical ... Van Andel research institute study provides new details of fundamental cellular process. 7. Cellular processing of proteins ... Agarwal noted that enzymes are present in every organism and are widely used in industry as catalysts in the production of ...
... a protein. Some proteins function as enzymes, catalysts that speed the chemical reactions in cells. Others are structural or ... Messenger RNA is then translated via cellular machinery called ribosomes into a string of amino acids -- ... Each codon designates an amino acid (the subunits of proteins). The three letter code is the same for all organisms (with a few ... Mutations in them do not get incorporated into proteins, so they have no effect on the fitness of an organism. Introns are ...
Discusses the role of enzyme supplements, prebiotic and probiotic complexes, and antioxidants in neutralizing and eliminating ... Enzymes are protein-based molecules that act as catalysts in biochemical reactions, triggering and supervising the reactions. ... ENZYME SUPPLEMENTS. People suffering from an acidified internal cellular environment are generally not eating enough vegetables ... Every enzyme has a specific function that no other enzyme can perform. Enzymes are necessary for the digestion of proteins, ...
Enzymes. Functional proteins catalyzing biochemical reactions. Involved in all essential body reactions Found in all body ... Enzymes The Biocatalysts. IUG, Spring 2014 Dr. Tarek Zaida. ... Without catalysts, most cellular reactions would take place too ... Enzymes -Biochemistry 3070. enzymes. enzymes. enzymes are biological catalysts. recall that by definition, catalysts alter the ... what is an enzyme?. and what is it made of?. an enzyme is a biological catalyst. it is a protein and made of a long chain of ...
All catalysts utilized in our study could be reused several times without losing their catalytic efficiency. All synthesized ... Each method has different reaction mechanisms according to the catalyst. The present methods have advantages, including one-pot ... The mechanism of the synthesized compounds (1-3) for killing bacteria may involve deactivation of different cellular enzymes, ... "Carbonic anhydrase as a model for biophysical and physical-organic studies of proteins and protein-ligand binding," Chemical ...
Not all biological catalysts are protein enzymes; RNA-based catalysts such as ribozymes and ribosomes are essential to many ... Some other examples of enzymes are phosphofructokinase and hexokinase, both of which are important for cellular respiration ( ... Enzymes are usually protein molecules that manipulate other molecules - the enzymes substrates. These target molecules bind to ... ISBN 0-471-30309-7. Fersht, Alan (1999). Structure and mechanism in protein science: a guide to enzyme catalysis and protein ...
However, organometallic catalysts perform poorly, if at all, in aqueous solutions or cellular-like environments, and need to be ... where compounds bound to biotin can be introduced into the protein to generate artificial enzymes. In this study the authors ... However, the environment inside a living cell is far from ideal for the proper functioning of organometallic-based enzymes. " ... These molecular factories will be used for industrial production, or to control cellular systems in health and disease. ...
Enzyme explanation free. What is Enzyme? Meaning of Enzyme medical term. What does Enzyme mean? ... Looking for online definition of Enzyme in the Medical Dictionary? ... Related to Enzyme: substrate, Enzyme kinetics. enzyme. [en´zīm] any protein that acts as a catalyst, increasing the rate at ... which serve as catalysts for cellular oxidations.. en·zyme. (enzīm), A macromolecule that acts as a catalyst to induce ...
Enzyme. a type of protein present in all cells that helps to act as a biological catalyst for cellular reactions. ... a region, located on an enzyme, that helps the enzyme bind to a protein or other cellular structure. ... a part of protein synthesis in which a portion of DNA is used to form messenger RNA. (The first process in protein synthesis.) ... a portion of protein synthesis in which messenger RNA is used to link together amino acids into full sized proteins. (The ...
... protein heterodimerization activity Cellular component • nucleus Biological ... Ubiquitination involves at least three classes ... However, enzymes do differ from most other catalysts in that they are highly specific for their substrates. Enzymes are known ... Most enzymes are proteins, although some catalytic RNA molecules have been identified. Enzymes adopt a specific three- ... Enzyme. Enzyme. Enzymes ( /ˈɛnzaɪmz/) are large biological molecules responsible for the thousands of chemical interconversions ...
... are the coenzymes that unite with specific apoenzyme proteins to form flavoprotein enzymes. Most of the flavin coenzyme systems ... Flavoproteins are catalysts in a number of mitochondrial oxidative and reductive reactions and function as electron ... Riboflavin is an essential component of coenzymes involved in multiple cellular metabolic pathways, including the energy- ... Most dietary riboflavin is ingested as food protein. [12] In the stomach, gastric acidity cleaves most of the coenzyme forms of ...
Some proteins are necessary for the structure of cells and tissues. Others, like enzymes, a class of active (catalyst) proteins ... catalyst) proteins, promote essential biochemical reactions, such as digestion, energy generation for cellular activity, or ... Other proteins control gene transcription in the preliminary stages of protein synthesis. Structural proteins help the DNA fold ... Other proteins control gene transcription in the preliminary stages of protein synthesis. Structural proteins help the DNA fold ...
6. Enzymes: The Catalysts of Life. 7. Membranes: Their Structure, Function, and Chemistry. 8. Transport Across Membranes: ... The Endomembrane System and Protein Trafficking. 13. Cytoskeletal Systems. 14. Cellular Movement: Motility and Contractility. ... Gene Expression II: Protein Synthesis and Sorting. 20. Regulation of Gene Expression. 21. Molecular Biology Techniques. 22. ... The Structural Basis of Cellular Information: DNA, Chromosomes, and Genome Organization. 17. DNA Replication, Repair, and ...
Some bind to cellular components to form ionic bonds on molecules, such as proteins, for support and shape. Others act as ... And some bind to enzymes in their catalytic domains to form active catalysts. ... This mineral seems to play a key role in cellular energy production, too, as well as for about 400 enzyme-catalyzed reactions ... They are higher in protein and lower in carbohydrate than a typical muffin thanks to the abundance of almond meal, cottage ...
An enzyme is a biological catalyst, but there are also inorganic catalysts. Enzymes are globular proteins synthesized within ... Enzymes play a role in reactions at the cellular level. More » www.reference.com › Science › Chemistry › Organic Chemistry ... An enzyme is a type of protein that is used by cells to speed up chemical reactions. It acts as a catalyst, which means it ... What Type of Organic Compound Is an Enzyme? An enzyme is in the class of organic compounds or molecules known as proteins or ...
... will help in the preparation of several competitive exams like SSC, UPSC, and PSC etc. ... Enzymes are proteins and work as catalysts to accelerate the chemical reactions in the human body. ... i) An Enzyme is a protein.. (ii) An Enzyme is used as a catalyst to accelerate the reaction.. (iii) Enzymes participate in ... cellular metabolic processes.. (iv) Life would not exist without the presence of enzymes.. Options are:. A. Both (i) and (ii) ...
  • Identification of specific mechanisms and enzyme(s) that catalyze formation of protein-SSG intermediates, however, is largely unknown and represents a prime objective for furthering understanding of this evolving mechanism of cellular regulation. (nih.gov)
  • Specifically, how do proteins catalyze the activation of molecular oxygen while avoiding the generation of radical intermediates with sufficient stability to carry out oxidative damage to cellular components. (berkeley.edu)
  • Protein disulfide isomerase (PDI) and PDI-like proteins contain thioredoxin domains that catalyze protein disulfide bond, inhibit aggregation of misfolded proteins, and function in isomerization during protein folding in endoplasmic reticulum and responses during abiotic stresses.Chinese cabbage is widely recognized as an economically important, nutritious vegetable, but its yield is severely hampered by various biotic and abiotic stresses. (biomedcentral.com)
  • Finally, RNA's central role in life suggests that its potential therapeutic value is barely tapped but already clinically validated: approximately 80 percent of antibiotics in use today target a single type of RNA-containing enzyme, the ribosome, and most do so by targeting its non-coding RNA component. (nih.gov)
  • Of course, the ribosome also contains numerous proteins as it is a very complex ribonucleoprotein particle but these predominantly serve structural functions, e.g. to give the ribosome its shape. (rechenkraft.net)
  • Furthermore, another group of RNA s, known as ribosomal RNA s (r RNA s), is used along with proteins to build the cellular structure known as the ribosome, which is the cellular location at which proteins are made. (apologeticspress.org)
  • The protein-r RNA complex that we know as the ribosome has long been known to serve as the site as well as the catalyst in forming the peptide bond. (apologeticspress.org)
  • Others act as gatekeepers, regulating the flow of nutrients through the protective membranes to the interior of cells and cellular compartments. (juvenon.com)
  • Cells maintain ion gradients by using sophisticated, energy-dependent membrane enzymes (membrane pumps) that are embedded in elaborate ion-tight membranes. (pnas.org)
  • Because nearly all eukaryotic proteins are synthesized in the cytosol, those destined to reside in a different location must cross membranes in an unfolded state and then fold and assemble in the compartment of destination. (plantcell.org)
  • Proteins are also important in cell signaling, immune responses, cell adhesion, active transport across membranes, and the cell cycle. (wikipedia.org)
  • with prokaryotic and eukaryotic version of their cell-free translation system, have also synthesized proteins with increased production, incorporating techniques like continuous flow to add materials and remove products. (wikipedia.org)
  • In the mid to late 1960s, the discovery that eukaryotic secreted proteins are first segregated in the lumen of the endoplasmic reticulum (ER) before traveling within membranous structures to reach the cell surface placed the ER at the start point of a newly recognized metabolic pathway now known as the secretory pathway ( Palade, 1975 ). (plantcell.org)
  • In eukaryotic cells, the protein threads are arranged as microfillaments and microtubules. (getrevising.co.uk)
  • In a publication selected as a '2007 Hot Article' by the journal Biochemistry, University at Buffalo chemists report the discovery of a central mechanism responsible for the action of the powerful biological catalysts known as enzymes. (innovations-report.com)
  • The cell membrane consists of lipids and proteins and is selectively permeable . (google.com)
  • Instead, cellular life forms have evolved numerous energy-requiring membrane transport systems to sustain redox and (electro)chemical gradients between their interior and the environment. (pnas.org)
  • However, the mechanisms of traffic along the secretory pathway involve only a single translocation event across the ER membrane, after which proteins do not have to cross any further membrane to reach other stations along the pathway. (plantcell.org)
  • Integral membrane proteins may also be synthesized with an N-terminal signal peptide, but their orientation within the ER membrane and the translocation of portions that will eventually reside in the lumen are determined by the corresponding membrane-spanning domains. (plantcell.org)
  • Removal is performed by signal peptidase, an enzyme located on the lumenal surface of the ER membrane. (plantcell.org)
  • If the protein contains a stop-transfer signal, as do many integral membrane proteins, then translocation is arrested, and the appropriate hydrophobic regions migrate laterally into the membrane to become transmembrane domains. (plantcell.org)
  • The membrane structure of E. coli cells is partially or entirely disrupted at high temperatures, and thus thermophilic enzymes, which are produced as soluble proteins, leak out of the cells ( 6 - 9 ). (asm.org)
  • To overcome this limitation, one potential strategy is the integration of thermophilic enzymes to the membrane structure of cells. (asm.org)
  • In our previous work, we found that the heat-induced leakage of a thermophilic glycerol kinase from recombinant E. coli cells could be prevented by fusing the enzyme to an E. coli membrane-intrinsic protein, YedZ ( 8 ). (asm.org)
  • A tight integration of the glycerol kinase to the E. coli membrane structure might have prohibited the conformational change of the enzyme, resulting in a decreased specific activity. (asm.org)
  • Thus, the screening for a suitable membrane-anchoring protein would be essential to mitigate the loss of the specific activity. (asm.org)
  • Those coupled to membrane depolarization or intracellular release of calcium include the receptor-mediated activation of cytotoxic functions in granulocytes and the synaptic potentiation of protein kinase activation. (harvard.edu)
  • The ribosomes on the RER make proteins that are excreted or attached to the cell membrane. (getrevising.co.uk)
  • Riboflavin is an essential component of coenzymes involved in multiple cellular metabolic pathways, including the energy-producing respiratory pathways. (medscape.com)