Xanthine Oxidase: An iron-molybdenum flavoprotein containing FLAVIN-ADENINE DINUCLEOTIDE that oxidizes hypoxanthine, some other purines and pterins, and aldehydes. Deficiency of the enzyme, an autosomal recessive trait, causes xanthinuria.Xanthine: A purine base found in most body tissues and fluids, certain plants, and some urinary calculi. It is an intermediate in the degradation of adenosine monophosphate to uric acid, being formed by oxidation of hypoxanthine. The methylated xanthine compounds caffeine, theobromine, and theophylline and their derivatives are used in medicine for their bronchodilator effects. (Dorland, 28th ed)Xanthine Dehydrogenase: An enzyme that catalyzes the oxidation of XANTHINE in the presence of NAD+ to form URIC ACID and NADH. It acts also on a variety of other purines and aldehydes.Xanthines: Purine bases found in body tissues and fluids and in some plants.Molybdenum: A metallic element with the atomic symbol Mo, atomic number 42, and atomic weight 95.94. It is an essential trace element, being a component of the enzymes xanthine oxidase, aldehyde oxidase, and nitrate reductase. (From Dorland, 27th ed)Coenzymes: Small molecules that are required for the catalytic function of ENZYMES. Many VITAMINS are coenzymes.Pteridines: Compounds based on pyrazino[2,3-d]pyrimidine which is a pyrimidine fused to a pyrazine, containing four NITROGEN atoms.Allopurinol: A XANTHINE OXIDASE inhibitor that decreases URIC ACID production. It also acts as an antimetabolite on some simpler organisms.Oxypurinol: A xanthine oxidase inhibitor.Heparin Cofactor II: A sulfated plasma protein with a MW of approximately 66kDa that resembles ANTITHROMBIN III. The protein is an inhibitor of thrombin in plasma and is activated by dermatan sulfate or heparin. It is a member of the serpin superfamily.Hypoxanthine: A purine and a reaction intermediate in the metabolism of adenosine and in the formation of nucleic acids by the salvage pathway.Hypoxanthines: Purine bases related to hypoxanthine, an intermediate product of uric acid synthesis and a breakdown product of adenine catabolism.Aldehyde Oxidase: An aldehyde oxidoreductase expressed predominantly in the LIVER; LUNGS; and KIDNEY. It catalyzes the oxidation of a variety of organic aldehydes and N-heterocyclic compounds to CARBOXYLIC ACIDS, and also oxidizes quinoline and pyridine derivatives. The enzyme utilizes molybdenum cofactor and FAD as cofactors.Metalloproteins: Proteins that have one or more tightly bound metal ions forming part of their structure. (Dorland, 28th ed)Tungsten: Tungsten. A metallic element with the atomic symbol W, atomic number 74, and atomic weight 183.85. It is used in many manufacturing applications, including increasing the hardness, toughness, and tensile strength of steel; manufacture of filaments for incandescent light bulbs; and in contact points for automotive and electrical apparatus.Uric Acid: An oxidation product, via XANTHINE OXIDASE, of oxypurines such as XANTHINE and HYPOXANTHINE. It is the final oxidation product of purine catabolism in humans and primates, whereas in most other mammals URATE OXIDASE further oxidizes it to ALLANTOIN.Ketone Oxidoreductases: Oxidoreductases that are specific for KETONES.Flavin-Adenine Dinucleotide: A condensation product of riboflavin and adenosine diphosphate. The coenzyme of various aerobic dehydrogenases, e.g., D-amino acid oxidase and L-amino acid oxidase. (Lehninger, Principles of Biochemistry, 1982, p972)Superoxides: Highly reactive compounds produced when oxygen is reduced by a single electron. In biological systems, they may be generated during the normal catalytic function of a number of enzymes and during the oxidation of hemoglobin to METHEMOGLOBIN. In living organisms, SUPEROXIDE DISMUTASE protects the cell from the deleterious effects of superoxides.Free Radicals: Highly reactive molecules with an unsatisfied electron valence pair. Free radicals are produced in both normal and pathological processes. They are proven or suspected agents of tissue damage in a wide variety of circumstances including radiation, damage from environment chemicals, and aging. Natural and pharmacological prevention of free radical damage is being actively investigated.Milk: The white liquid secreted by the mammary glands. It contains proteins, sugar, lipids, vitamins, and minerals.Kinetics: The rate dynamics in chemical or physical systems.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).PQQ Cofactor: A pyrrolo-quinoline having two adjacent keto-groups at the 4 and 5 positions and three acidic carboxyl groups. It is a coenzyme of some DEHYDROGENASES.Pterins: Compounds based on 2-amino-4-hydroxypteridine.Purines: A series of heterocyclic compounds that are variously substituted in nature and are known also as purine bases. They include ADENINE and GUANINE, constituents of nucleic acids, as well as many alkaloids such as CAFFEINE and THEOPHYLLINE. Uric acid is the metabolic end product of purine metabolism.Electron Spin Resonance Spectroscopy: A technique applicable to the wide variety of substances which exhibit paramagnetism because of the magnetic moments of unpaired electrons. The spectra are useful for detection and identification, for determination of electron structure, for study of interactions between molecules, and for measurement of nuclear spins and moments. (From McGraw-Hill Encyclopedia of Science and Technology, 7th edition) Electron nuclear double resonance (ENDOR) spectroscopy is a variant of the technique which can give enhanced resolution. Electron spin resonance analysis can now be used in vivo, including imaging applications such as MAGNETIC RESONANCE IMAGING.Tungsten Compounds: Inorganic compounds that contain tungsten as an integral part of the molecule.NAD: A coenzyme composed of ribosylnicotinamide 5'-diphosphate coupled to adenosine 5'-phosphate by pyrophosphate linkage. It is found widely in nature and is involved in numerous enzymatic reactions in which it serves as an electron carrier by being alternately oxidized (NAD+) and reduced (NADH). (Dorland, 27th ed)Molybdoferredoxin: A non-heme iron-sulfur protein isolated from Clostridium pasteurianum and other bacteria. It is a component of NITROGENASE, which is active in nitrogen fixation, and consists of two subunits with molecular weights of 59.5 kDa and 50.7 kDa, respectively.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.Binding Sites: The parts of a macromolecule that directly participate in its specific combination with another molecule.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.Superoxide Dismutase: An oxidoreductase that catalyzes the reaction between superoxide anions and hydrogen to yield molecular oxygen and hydrogen peroxide. The enzyme protects the cell against dangerous levels of superoxide. EC 1.15.1.1.Hydroxides: Inorganic compounds that contain the OH- group.Biopterin: A natural product that has been considered as a growth factor for some insects.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)Antigens, CD46: A ubiquitously expressed complement receptor that binds COMPLEMENT C3B and COMPLEMENT C4B and serves as a cofactor for their inactivation. CD46 also interacts with a wide variety of pathogens and mediates immune response.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.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.Catalysis: The facilitation of a chemical reaction by material (catalyst) that is not consumed by the reaction.Flavins: Derivatives of the dimethylisoalloxazine (7,8-dimethylbenzo[g]pteridine-2,4(3H,10H)-dione) skeleton. Flavin derivatives serve an electron transfer function as ENZYME COFACTORS in FLAVOPROTEINS.Models, Molecular: Models used experimentally or theoretically to study molecular shape, electronic properties, or interactions; includes analogous molecules, computer-generated graphics, and mechanical structures.Oxygen: An element with atomic symbol O, atomic number 8, and atomic weight [15.99903; 15.99977]. It is the most abundant element on earth and essential for respiration.Theobromine: 3,7-Dimethylxanthine. The principle alkaloid in Theobroma cacao (the cacao bean) and other plants. A xanthine alkaloid that is used as a bronchodilator and as a vasodilator. It has a weaker diuretic activity than THEOPHYLLINE and is also a less powerful stimulant of smooth muscle. It has practically no stimulant effect on the central nervous system. It was formerly used as a diuretic and in the treatment of angina pectoris and hypertension. (From Martindale, The Extra Pharmacopoeia, 30th ed, pp1318-9)Aldehyde Oxidoreductases: Oxidoreductases that are specific for ALDEHYDES.Sulfurtransferases: Enzymes which transfer sulfur atoms to various acceptor molecules. EC 2.8.1.Hydrogen Peroxide: A strong oxidizing agent used in aqueous solution as a ripening agent, bleach, and topical anti-infective. It is relatively unstable and solutions deteriorate over time unless stabilized by the addition of acetanilide or similar organic materials.Hydroxyl Radical: The univalent radical OH. Hydroxyl radical is a potent oxidizing agent.Urate Oxidase: An enzyme that catalyzes the conversion of urate and unidentified products. It is a copper protein. The initial products decompose to form allantoin. EC 1.7.3.3.Dithionite: Dithionite. The dithionous acid ion and its salts.Spectrophotometry: The art or process of comparing photometrically the relative intensities of the light in different parts of the spectrum.NADP: Nicotinamide adenine dinucleotide phosphate. A coenzyme composed of ribosylnicotinamide 5'-phosphate (NMN) coupled by pyrophosphate linkage to the 5'-phosphate adenosine 2',5'-bisphosphate. It serves as an electron carrier in a number of reactions, being alternately oxidized (NADP+) and reduced (NADPH). (Dorland, 27th ed)Reactive Oxygen Species: Molecules or ions formed by the incomplete one-electron reduction of oxygen. These reactive oxygen intermediates include SINGLET OXYGEN; SUPEROXIDES; PEROXIDES; HYDROXYL RADICAL; and HYPOCHLOROUS ACID. They contribute to the microbicidal activity of PHAGOCYTES, regulation of signal transduction and gene expression, and the oxidative damage to NUCLEIC ACIDS; PROTEINS; and LIPIDS.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.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.Crystallography, X-Ray: The study of crystal structure using X-RAY DIFFRACTION techniques. (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)Sulfur: An element that is a member of the chalcogen family. It has an atomic symbol S, atomic number 16, and atomic weight [32.059; 32.076]. It is found in the amino acids cysteine and methionine.Catalase: An oxidoreductase that catalyzes the conversion of HYDROGEN PEROXIDE to water and oxygen. It is present in many animal cells. A deficiency of this enzyme results in ACATALASIA.Free Radical Scavengers: Substances that influence the course of a chemical reaction by ready combination with free radicals. Among other effects, this combining activity protects pancreatic islets against damage by cytokines and prevents myocardial and pulmonary perfusion injuries.Oxidoreductases Acting on Sulfur Group Donors: Oxidoreductases with specificity for oxidation or reduction of SULFUR COMPOUNDS.Nitrate Reductases: Oxidoreductases that are specific for the reduction of NITRATES.Liver: A large lobed glandular organ in the abdomen of vertebrates that is responsible for detoxification, metabolism, synthesis and storage of various substances.Iron: A metallic element with atomic symbol Fe, atomic number 26, and atomic weight 55.85. It is an essential constituent of HEMOGLOBINS; CYTOCHROMES; and IRON-BINDING PROTEINS. It plays a role in cellular redox reactions and in the transport of OXYGEN.Recombinant Proteins: Proteins prepared by recombinant DNA technology.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.Nucleobase Transport Proteins: Proteins involved in the transport of nucleobases such as PYRIMIDINES and PURINES across membranes.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).Rhodobacter capsulatus: Non-pathogenic ovoid to rod-shaped bacteria that are widely distributed and found in fresh water as well as marine and hypersaline habitats.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.Nitrogenase: An enzyme system that catalyzes the fixing of nitrogen in soil bacteria and blue-green algae (CYANOBACTERIA). EC 1.18.6.1.Catalytic Domain: The region of an enzyme that interacts with its substrate to cause the enzymatic reaction.Guanine Deaminase: An enzyme that catalyzes the deamination of guanine to form xanthine. EC 3.5.4.3.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)Nitric Oxide: A free radical gas produced endogenously by a variety of mammalian cells, synthesized from ARGININE by NITRIC OXIDE SYNTHASE. Nitric oxide is one of the ENDOTHELIUM-DEPENDENT RELAXING FACTORS released by the vascular endothelium and mediates VASODILATION. It also inhibits platelet aggregation, induces disaggregation of aggregated platelets, and inhibits platelet adhesion to the vascular endothelium. Nitric oxide activates cytosolic GUANYLATE CYCLASE and thus elevates intracellular levels of CYCLIC GMP.Purine-Pyrimidine Metabolism, Inborn ErrorsPyridoxal Phosphate: This is the active form of VITAMIN B 6 serving as a coenzyme for synthesis of amino acids, neurotransmitters (serotonin, norepinephrine), sphingolipids, aminolevulinic acid. During transamination of amino acids, pyridoxal phosphate is transiently converted into pyridoxamine phosphate (PYRIDOXAMINE).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.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.Pentosyltransferases: Enzymes of the transferase class that catalyze the transfer of a pentose group from one compound to another.Oxidative Stress: A disturbance in the prooxidant-antioxidant balance in favor of the former, leading to potential damage. Indicators of oxidative stress include damaged DNA bases, protein oxidation products, and lipid peroxidation products (Sies, Oxidative Stress, 1991, pxv-xvi).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.Iron-Sulfur Proteins: A group of proteins possessing only the iron-sulfur complex as the prosthetic group. These proteins participate in all major pathways of electron transport: photosynthesis, respiration, hydroxylation and bacterial hydrogen and nitrogen fixation.Base Sequence: The sequence of PURINES and PYRIMIDINES in nucleic acids and polynucleotides. It is also called nucleotide sequence.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.Adenosine: A nucleoside that is composed of ADENINE and D-RIBOSE. Adenosine or adenosine derivatives play many important biological roles in addition to being components of DNA and RNA. Adenosine itself is a neurotransmitter.Apoenzymes: The protein components of enzyme complexes (HOLOENZYMES). An apoenzyme is the holoenzyme minus any cofactors (ENZYME COFACTORS) or prosthetic groups required for the enzymatic function.Azotobacter vinelandii: A species of gram-negative, aerobic bacteria first isolated from soil in Vineland, New Jersey. Ammonium and nitrate are used as nitrogen sources by this bacterium. It is distinguished from other members of its genus by the ability to use rhamnose as a carbon source. (From Bergey's Manual of Determinative Bacteriology, 9th ed)FlavoproteinsAntioxidants: Naturally occurring or synthetic substances that inhibit or retard the oxidation of a substance to which it is added. They counteract the harmful and damaging effects of oxidation in animal tissues.Mutagenesis, Site-Directed: Genetically engineered MUTAGENESIS at a specific site in the DNA molecule that introduces a base substitution, or an insertion or deletion.Dermatan Sulfate: A naturally occurring glycosaminoglycan found mostly in the skin and in connective tissue. It differs from CHONDROITIN SULFATE A (see CHONDROITIN SULFATES) by containing IDURONIC ACID in place of glucuronic acid, its epimer, at carbon atom 5. (from Merck, 12th ed)NADPH Oxidase: A flavoprotein enzyme that catalyzes the univalent reduction of OXYGEN using NADPH as an electron donor to create SUPEROXIDE ANION. The enzyme is dependent on a variety of CYTOCHROMES. Defects in the production of superoxide ions by enzymes such as NADPH oxidase result in GRANULOMATOUS DISEASE, CHRONIC.Chromatography, High Pressure Liquid: Liquid chromatographic techniques which feature high inlet pressures, high sensitivity, and high speed.Theophylline: A methyl xanthine derivative from tea with diuretic, smooth muscle relaxant, bronchial dilation, cardiac and central nervous system stimulant activities. Theophylline inhibits the 3',5'-CYCLIC NUCLEOTIDE PHOSPHODIESTERASE that degrades CYCLIC AMP thus potentiates the actions of agents that act through ADENYLYL CYCLASES and cyclic AMP.BenzaldehydesFactor Va: Activated form of factor V. It is an essential cofactor for the activation of prothrombin catalyzed by factor Xa.Indolequinones: INDOLES which have two keto groups forming QUINONES like structures of the indole aromatic ring.Cyclic N-Oxides: Heterocyclic compounds in which an oxygen is attached to a cyclic nitrogen.Bacterial Proteins: Proteins found in any species of bacterium.Receptors, Purinergic: Cell surface proteins that bind PURINES with high affinity and trigger intracellular changes which influence the behavior of cells. The best characterized classes of purinergic receptors in mammals are the P1 receptors, which prefer ADENOSINE, and the P2 receptors, which prefer ATP or ADP.Thrombin: An enzyme formed from PROTHROMBIN that converts FIBRINOGEN to FIBRIN.Sulfite Oxidase: A MOLYBDENUM requiring enzyme that catalyzes the terminal reaction in the oxidative degradation of SULFUR AMINO ACIDS with the formation of a sulfate. A deficiency of sulfite oxidase results in sulfocysteinuria.Xanthopterin: 2-Amino-1,5-dihydro-4,6-pteridinedione. Pigment first discovered in butterfly wings and widely distributed in plants and animals.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.GTP Cyclohydrolase: (GTP cyclohydrolase I) or GTP 7,8-8,9-dihydrolase (pyrophosphate-forming) (GTP cyclohydrolase II). An enzyme group that hydrolyzes the imidazole ring of GTP, releasing carbon-8 as formate. Two C-N bonds are hydrolyzed and the pentase unit is isomerized. This is the first step in the synthesis of folic acid from GTP. EC 3.5.4.16 (GTP cyclohydrolase I) and EC 3.5.4.25 (GTP cyclohydrolase II).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.Inosine: A purine nucleoside that has hypoxanthine linked by the N9 nitrogen to the C1 carbon of ribose. It is an intermediate in the degradation of purines and purine nucleosides to uric acid and in pathways of purine salvage. It also occurs in the anticodon of certain transfer RNA molecules. (Dorland, 28th ed)Dose-Response Relationship, Drug: The relationship between the dose of an administered drug and the response of the organism to the drug.Oxidants: Electron-accepting molecules in chemical reactions in which electrons are transferred from one molecule to another (OXIDATION-REDUCTION).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.Nitrate Reductase: An enzyme that catalyzes the oxidation of nitrite to nitrate. It is a cytochrome protein that contains IRON and MOLYBDENUM.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.Veillonella: A genus of gram-negative, anaerobic cocci parasitic in the mouth and in the intestinal and respiratory tracts of man and other animals.Spectrophotometry, Ultraviolet: Determination of the spectra of ultraviolet absorption by specific molecules in gases or liquids, for example Cl2, SO2, NO2, CS2, ozone, mercury vapor, and various unsaturated compounds. (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)Flavin Mononucleotide: A coenzyme for a number of oxidative enzymes including NADH DEHYDROGENASE. It is the principal form in which RIBOFLAVIN is found in cells and tissues.Allantoin: A urea hydantoin that is found in URINE and PLANTS and is used in dermatological preparations.Cell Line: Established cell cultures that have the potential to propagate indefinitely.Nitrates: Inorganic or organic salts and esters of nitric acid. These compounds contain the NO3- radical.Nitrites: Salts of nitrous acid or compounds containing the group NO2-. The inorganic nitrites of the type MNO2 (where M=metal) are all insoluble, except the alkali nitrites. The organic nitrites may be isomeric, but not identical with the corresponding nitro compounds. (Grant & Hackh's Chemical Dictionary, 5th ed)Complement Inactivator Proteins: Serum proteins that negatively regulate the cascade process of COMPLEMENT ACTIVATION. Uncontrolled complement activation and resulting cell lysis is potentially dangerous for the host. The complement system is tightly regulated by inactivators that accelerate the decay of intermediates and certain cell surface receptors.Electrophoresis, Polyacrylamide Gel: Electrophoresis in which a polyacrylamide gel is used as the diffusion medium.NADH, NADPH Oxidoreductases: A group of oxidoreductases that act on NADH or NADPH. In general, enzymes using NADH or NADPH to reduce a substrate are classified according to the reverse reaction, in which NAD+ or NADP+ is formally regarded as an acceptor. This subclass includes only those enzymes in which some other redox carrier is the acceptor. (Enzyme Nomenclature, 1992, p100) EC 1.6.Purinergic P1 Receptor Antagonists: Compounds that bind to and block the stimulation of PURINERGIC P1 RECEPTORS.Metal Metabolism, Inborn ErrorsSpectrum Analysis: The measurement of the amplitude of the components of a complex waveform throughout the frequency range of the waveform. (McGraw-Hill Dictionary of Scientific and Technical Terms, 6th ed)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.Manganese: A trace element with atomic symbol Mn, atomic number 25, and atomic weight 54.94. It is concentrated in cell mitochondria, mostly in the pituitary gland, liver, pancreas, kidney, and bone, influences the synthesis of mucopolysaccharides, stimulates hepatic synthesis of cholesterol and fatty acids, and is a cofactor in many enzymes, including arginase and alkaline phosphatase in the liver. (From AMA Drug Evaluations Annual 1992, p2035)2,6-Dichloroindophenol: A dye used as a reagent in the determination of vitamin C.Chemical Phenomena: The composition, conformation, and properties of atoms and molecules, and their reaction and interaction processes.Endothelium, Vascular: Single pavement layer of cells which line the luminal surface of the entire vascular system and regulate the transport of macromolecules and blood components.1-Methyl-3-isobutylxanthine: A potent cyclic nucleotide phosphodiesterase inhibitor; due to this action, the compound increases cyclic AMP and cyclic GMP in tissue and thereby activates CYCLIC NUCLEOTIDE-REGULATED PROTEIN KINASESSequence 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.Glucose Oxidase: An enzyme of the oxidoreductase class that catalyzes the conversion of beta-D-glucose and oxygen to D-glucono-1,5-lactone and peroxide. It is a flavoprotein, highly specific for beta-D-glucose. The enzyme is produced by Penicillium notatum and other fungi and has antibacterial activity in the presence of glucose and oxygen. It is used to estimate glucose concentration in blood or urine samples through the formation of colored dyes by the hydrogen peroxide produced in the reaction. (From Enzyme Nomenclature, 1992) EC 1.1.3.4.Uricosuric Agents: Gout suppressants that act directly on the renal tubule to increase the excretion of uric acid, thus reducing its concentrations in plasma.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).Time Factors: Elements of limited time intervals, contributing to particular results or situations.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.Rats, Sprague-Dawley: A strain of albino rat used widely for experimental purposes because of its calmness and ease of handling. It was developed by the Sprague-Dawley Animal Company.Purine Nucleotides: Purines attached to a RIBOSE and a phosphate that can polymerize to form DNA and RNA.Caffeine: A methylxanthine naturally occurring in some beverages and also used as a pharmacological agent. Caffeine's most notable pharmacological effect is as a central nervous system stimulant, increasing alertness and producing agitation. It also relaxes SMOOTH MUSCLE, stimulates CARDIAC MUSCLE, stimulates DIURESIS, and appears to be useful in the treatment of some types of headache. Several cellular actions of caffeine have been observed, but it is not entirely clear how each contributes to its pharmacological profile. Among the most important are inhibition of cyclic nucleotide PHOSPHODIESTERASES, antagonism of ADENOSINE RECEPTORS, and modulation of intracellular calcium handling.Molecular Weight: The sum of the weight of all the atoms in a molecule.Amine Oxidase (Copper-Containing): A group of enzymes including those oxidizing primary monoamines, diamines, and histamine. They are copper proteins, and, as their action depends on a carbonyl group, they are sensitive to inhibition by semicarbazide.Hyperuricemia: Excessive URIC ACID or urate in blood as defined by its solubility in plasma at 37 degrees C; greater than 0.42mmol per liter (7.0mg/dL) in men or 0.36mmol per liter (6.0mg/dL) in women. This condition is caused by overproduction of uric acid or impaired renal clearance. Hyperuricemia can be acquired, drug-induced or genetically determined (LESCH-NYHAN SYNDROME). It is associated with HYPERTENSION and GOUT.GuanineDithiothreitol: A reagent commonly used in biochemical studies as a protective agent to prevent the oxidation of SH (thiol) groups and for reducing disulphides to dithiols.Electron Transport: The process by which ELECTRONS are transported from a reduced substrate to molecular OXYGEN. (From Bennington, Saunders Dictionary and Encyclopedia of Laboratory Medicine and Technology, 1984, p270)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.Copper: A heavy metal trace element with the atomic symbol Cu, atomic number 29, and atomic weight 63.55.S-Adenosylmethionine: Physiologic methyl radical donor involved in enzymatic transmethylation reactions and present in all living organisms. It possesses anti-inflammatory activity and has been used in treatment of chronic liver disease. (From Merck, 11th ed)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.Phenylalanine Hydroxylase: An enzyme of the oxidoreductase class that catalyzes the formation of L-TYROSINE, dihydrobiopterin, and water from L-PHENYLALANINE, tetrahydrobiopterin, and oxygen. Deficiency of this enzyme may cause PHENYLKETONURIAS and PHENYLKETONURIA, MATERNAL. EC 1.14.16.1.Iodides: Inorganic binary compounds of iodine or the I- ion.Dimerization: The process by which two molecules of the same chemical composition form a condensation product or polymer.Thiamine Pyrophosphate: The coenzyme form of Vitamin B1 present in many animal tissues. It is a required intermediate in the PYRUVATE DEHYDROGENASE COMPLEX and the KETOGLUTARATE DEHYDROGENASE COMPLEX.Aldehydes: Organic compounds containing a carbonyl group in the form -CHO.Acetophenones2-Chloroadenosine: 2-Chloroadenosine. A metabolically stable analog of adenosine which acts as an adenosine receptor agonist. The compound has a potent effect on the peripheral and central nervous system.Complement C4b: The large fragment formed when COMPLEMENT C4 is cleaved by COMPLEMENT C1S. The membrane-bound C4b binds COMPLEMENT C2A, a SERINE PROTEASE, to form C4b2a (CLASSICAL PATHWAY C3 CONVERTASE) and subsequent C4b2a3b (CLASSICAL PATHWAY C5 CONVERTASE).Sodium Nitrite: Nitrous acid sodium salt. Used in many industrial processes, in meat curing, coloring, and preserving, and as a reagent in ANALYTICAL CHEMISTRY TECHNIQUES. It is used therapeutically as an antidote in cyanide poisoning. The compound is toxic and mutagenic and will react in vivo with secondary or tertiary amines thereby producing highly carcinogenic nitrosamines.Anaerobiosis: The complete absence, or (loosely) the paucity, of gaseous or dissolved elemental oxygen in a given place or environment. (From Singleton & Sainsbury, Dictionary of Microbiology and Molecular Biology, 2d ed)Chromatography, Gel: Chromatography on non-ionic gels without regard to the mechanism of solute discrimination.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.Adenine: A purine base and a fundamental unit of ADENINE NUCLEOTIDES.Glutathione: A tripeptide with many roles in cells. It conjugates to drugs to make them more soluble for excretion, is a cofactor for some enzymes, is involved in protein disulfide bond rearrangement and reduces peroxides.Biocatalysis: The facilitation of biochemical reactions with the aid of naturally occurring catalysts such as ENZYMES.Gout Suppressants: Agents that increase uric acid excretion by the kidney (URICOSURIC AGENTS), decrease uric acid production (antihyperuricemics), or alleviate the pain and inflammation of acute attacks of gout.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.Hydroxylation: Placing of a hydroxyl group on a compound in a position where one did not exist before. (Stedman, 26th ed)Cysteine: A thiol-containing non-essential amino acid that is oxidized to form CYSTINE.Oxidoreductases Acting on CH-NH Group Donors: Enzymes catalyzing the dehydrogenation of secondary amines, introducing a C=N double bond as the primary reaction. In some cases this is later hydrolyzed.CobamidesApoproteins: The protein components of a number of complexes, such as enzymes (APOENZYMES), ferritin (APOFERRITINS), or lipoproteins (APOLIPOPROTEINS).Sulfhydryl Compounds: Compounds containing the -SH radical.Complement C3b: The larger fragment generated from the cleavage of COMPLEMENT C3 by C3 CONVERTASE. It is a constituent of the ALTERNATIVE PATHWAY C3 CONVERTASE (C3bBb), and COMPLEMENT C5 CONVERTASES in both the classical (C4b2a3b) and the alternative (C3bBb3b) pathway. C3b participates in IMMUNE ADHERENCE REACTION and enhances PHAGOCYTOSIS. It can be inactivated (iC3b) or cleaved by various proteases to yield fragments such as COMPLEMENT C3C; COMPLEMENT C3D; C3e; C3f; and C3g.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.Receptors, Purinergic P1: A class of cell surface receptors that prefer ADENOSINE to other endogenous PURINES. Purinergic P1 receptors are widespread in the body including the cardiovascular, respiratory, immune, and nervous systems. There are at least two pharmacologically distinguishable types (A1 and A2, or Ri and Ra).Transcription Factors: Endogenous substances, usually proteins, which are effective in the initiation, stimulation, or termination of the genetic transcription process.Escherichia coli Proteins: Proteins obtained from ESCHERICHIA COLI.Tetrahydrofolates: Compounds based on 5,6,7,8-tetrahydrofolate.Purine Nucleosides: Purines with a RIBOSE attached that can be phosphorylated to PURINE NUCLEOTIDES.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.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.Peroxidase: A hemeprotein from leukocytes. Deficiency of this enzyme leads to a hereditary disorder coupled with disseminated moniliasis. It catalyzes the conversion of a donor and peroxide to an oxidized donor and water. EC 1.11.1.7.Luminescent Measurements: Techniques used for determining the values of photometric parameters of light resulting from LUMINESCENCE.Arthrobacter: A genus of asporogenous bacteria isolated from soil that displays a distinctive rod-coccus growth cycle.Models, Biological: Theoretical representations that simulate the behavior or activity of biological processes or diseases. For disease models in living animals, DISEASE MODELS, ANIMAL is available. Biological models include the use of mathematical equations, computers, and other electronic equipment.Pentoxifylline: A METHYLXANTHINE derivative that inhibits phosphodiesterase and affects blood rheology. It improves blood flow by increasing erythrocyte and leukocyte flexibility. It also inhibits platelet aggregation. Pentoxifylline modulates immunologic activity by stimulating cytokine production.Rats, Wistar: A strain of albino rat developed at the Wistar Institute that has spread widely at other institutions. This has markedly diluted the original strain.PorphobilinogenLipid Peroxidation: Peroxidase catalyzed oxidation of lipids using hydrogen peroxide as an electron acceptor.NADH Tetrazolium Reductase: Catalyzes the reduction of tetrazolium compounds in the presence of NADH.Guinea Pigs: A common name used for the genus Cavia. The most common species is Cavia porcellus which is the domesticated guinea pig used for pets and biomedical research.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.Adenosine-5'-(N-ethylcarboxamide): A stable adenosine A1 and A2 receptor agonist. Experimentally, it inhibits cAMP and cGMP phosphodiesterase activity.Onium Compounds: Ions with the suffix -onium, indicating cations with coordination number 4 of the type RxA+ which are analogous to QUATERNARY AMMONIUM COMPOUNDS (H4N+). Ions include phosphonium R4P+, oxonium R3O+, sulfonium R3S+, chloronium R2Cl+
Tetrahydroxypteridine cycloisomerase
Aldehyde oxidase and xanthine dehydrogenase, a/b hammerhead domain
L-xylulose reductase
Homoisocitrate dehydrogenase
3-oxoacyl-(acyl-carrier-protein) reductase
Cholest-5-ene-3beta,7alpha-diol 3beta-dehydrogenase
Composition of the human body
Adenosine diphosphate
Identification of Crucial Amino Acids in Mouse Aldehyde Oxidase 3 That Determine Substrate Specificity - pdf descargar
Absence of hepatic molybdenum cofactor: an inborn error of metabolism leading to a combined deficiency of sulphite oxidase and...
Inborn errors of molybdenum metabolism: combined deficiencies of sulfite oxidase and xanthine dehydrogenase in a patient...
Aldehyde oxidase and xanthine dehydrogenase, a/b hammerhead domain - Wikipedia
Inborn Errors of Metabolism in Infancy and Early Childhood: An Update - American Family Physician
Molybdenum cofactor deficiency: MedlinePlus Genetics
Molybdenum
Medical Genetics Test Details - Baylor Genetics Laboratories - Baylor College of Medicine, Houston, Texas
Molybdenum: Uses, Side Effects, Interactions, Dosage, and Warning
Xanthine | definition of xanthine by Medical dictionary
JCI -
S-sulfocysteine/NMDA receptor-dependent signaling underlies neurodegeneration in molybdenum cofactor deficiency
Xdh - Xdh - Drosophila mojavensis (Fruit fly) - Xdh gene & protein
MOCS1 Gene - GeneCards | MOCS1 Protein | MOCS1 Antibody
Biomonitoring Summary | CDC
Genetic dissection of cyclic pyranopterin monophosphate biosynthesis in plant mitochondria | Biochemical Journal
Aldehyde oxidase/xanthine dehydrogenase, a/b hammerhead (IPR000674) | InterPro | EMBL-EBI
Hypoxanthine oxidase | definition of hypoxanthine oxidase by Medical dictionary
Molybdenum cofactor deficiency mimics cerebral palsy: differentiating factors for diagnosis.
JCI -
From ST segments to endothelial pathophysiology: hypercholesterolemia and endothelial superoxide production
Publications - Molecular Enzymology - Prof. Dr. Silke Leimkühler - University of Potsdam
Plus it
Optimization of the Expression of Human Aldehyde Oxidase for Investigations of Single-Nucleotide Polymorphisms | Drug...
The mammalian aldehyde oxidase gene family. - PubMed - NCBI
molybdenum
Frontiers | Expression of ABA Metabolism-Related Genes Suggests Similarities and Differences Between Seed Dormancy and Bud...
EnzymesOxidoreductaseEnzymeProteinXanthinuriaPatients with molybdenum cofactor deficiencyMOCS1Uric acidUrateMember of the xanthine oxidaseMOCS2OxidoreductasesComponent of the molybdenum cofactorBiosynthesis of the molybdenum cofactorsCaused by molybdenum cofactor deficiencyFeatures of molybdenum cofactor deficiencyLacking the molybdenum cofactorDehydrogenase and aldehyde oxidaseDeficiency of xanthine dehydrogenaseIron-molybdenum cofactorMetabolismSynthesisSulfite oxidase and xanthineUrinaryAldehyde oxidase and xanthineBindsSulfurGenesActive molybdenum cofactorNitrateFormation of xanthineMetabolicPathwaysGenePyranopterin-basedBoundInhibitionCharacterizationOxidase revealedLigandPterinEscherichiaAutosomal recessiveLiver
Enzymes38
- This remarkable coincidence of three inborn errors of metabolism in a single individual was demonstrated to result from a deficiency of the 'molybdenum cofactor', an essential constituent of all three enzymes. (biomedsearch.com)
- The metabolic defect responsible for loss of both enzyme activities appears to be at the level of the molybdenum cofactor common to the two enzymes. (duke.edu)
- Molybdopterins are a class of cofactors found in most molybdenum (Mo) and all tungsten (W) enzymes. (wikipedia.org)
- Enzymes that contain the molybdopterin cofactor include xanthine oxidase, DMSO reductase, sulfite oxidase, and nitrate reductase. (wikipedia.org)
- In this case, the tungsten-selenium pair has been speculated to function analogously to the molybdenum-sulfur pairing of some molybdenum cofactor-requiring enzymes. (wikipedia.org)
- Enzymes that use molydopterin as cofactor or prosthetic group are given below. (wikipedia.org)
- Molybdenum cofactor, which contains the element molybdenum, is essential to the function of several enzymes. (medlineplus.gov)
- Without the cofactor, the metabolic enzymes that rely on it cannot function. (medlineplus.gov)
- Sulfite, which is normally broken down by one of the molybdenum cofactor-dependent enzymes, is toxic, especially to the brain. (medlineplus.gov)
- The trace element molybdenum is essential for nearly all organisms and forms the catalytic centre of a large variety of enzymes such as nitrogenase, nitrate reductases, sulphite oxidase and xanthine oxidoreductases. (nature.com)
- There are only a few Moco enzymes known in eukaryotes: xanthine dehydrogenase (XDH) in purine catabolism, aldehyde oxidase (AldOx), sulfite oxidase, the mitochondrial amidoxime-reducing components mARC1 and mARC2, and nitrate reductase [ 3 , 4 ]. (biochemj.org)
- These enzymes catalyze the oxidation of hypoxanthine to xanthine and can further catalyze the oxidation of xanthine to uric acid. (wikipedia.org)
- hypoxanthine (one oxygen atom) xanthine (two oxygens) uric acid (three oxygens) Because XO is a superoxide-producing enzyme, with general low specificity, it can be combined with other compounds and enzymes and create reactive oxidants, as well as oxidize other substrates. (wikipedia.org)
- These enzymes require a molybdo-pterin cofactor (molybdenum cofactor, MoCo) and flavin adenine dinucleotide for their catalytic activity. (nih.gov)
- With the exception of bacterial nitrogenase, all Mo-dependent enzymes contain a unique pyranopterin-based cofactor coordinating a Mo atom at their catalytic site. (asmscience.org)
- Molybdenum enzymes containing the pyranopterin cofactor: an overview. (asmscience.org)
- Molybdate and tungstate: uptake, homeostasis, cofactors and enzymes. (asmscience.org)
- PART III: MOLYBDENUM 357 MOLYBDENUM M olybdenum functions as a cofactor for several enzymes, including sulfite oxidase, xanthine oxidase, and aldehyde oxidase. (nap.edu)
- MOLYBDENUM AND THE BODY Function Molybdenum, in a form called molybdopterin, acts as a cofactor for several enzymes, including sulfite oxidase, xanthine oxidase, and aldehyde oxidase. (nap.edu)
- Moco-containing enzymes are divided further into three different families, the xanthine oxidase (XO) family, the sulfite oxidase family, and the dimethyl sulfoxide reductase family, which are classified in accordance to the ligands at the molybdenum active site ( Hille, 1996 ). (aspetjournals.org)
- ABA3 is essential for activation of the molybdenum enzymes AO and xanthine dehydrogenase (XDH). (scirp.org)
- Molybdenum cofactor is a cofactor required for the activity of enzymes such as sulfite oxidase, xanthine oxidoreductase, and aldehyde oxidase. (hmdb.ca)
- In animals and plants these enzymes use molybdenum bound at the active site in a tricyclic molybdenum cofactor. (hmdb.ca)
- All molybdenum-using enzymes so far identified in nature use this cofactor The simplest structure of molybdopterin contains a pyranopterin coordinated to molybdenum. (hmdb.ca)
- Current projects address sulfur transfer during the assembly of molybdenum cofactors and structure-function studies on enzymes of the xanthine oxidase and DMSO reductase families of molybdoenzymes. (uni-potsdam.de)
- Sulfation of molybdenum is essential for xanthine dehydrogenase (XDH) and aldehyde oxidase (ADO) enzymes in which molybdenum cofactor is liganded by 1 oxygen and 1 sulfur atom in active form. (uniprot.org)
- Molybdenum cofactor, which contains the element molybdenum, is essential to the function of several enzymes called sulfite oxidase, aldehyde oxidase, xanthine dehydrogenase, and mitochondrial amidoxime reducing component (mARC). (nih.gov)
- The deduced amino acid sequences show considerable similarities to a group of hydroxylating enzymes involved in CO, xanthine, and nicotine metabolism that have conserved binding sites for [2Fe-2S] clusters and a molybdenum cofactor. (asm.org)
- MFEs are enzymes that contain flavin adenine dinucleotide (FAD), iron sulphur domain [2Fe-2S] and molybdenum cofactor domain (Moco). (hud.ac.uk)
- This condition is inherited recessively and is caused by a congenital defect of a molybdenum-containing cofactor essential for the function of 3 distinct enzymes (ie, xanthine dehydrogenase, aldehyde oxidase, sulfite oxidase). (medscape.com)
- These enzymes are responsible for the breakdown of xanthine, hypoxanthine, and sulfite, and the detoxification of many harmful compounds. (baycare.org)
- With the exception of bacterial nitrogenase, where Mo is a constituent of the FeMo-cofactor, Mo is bound to a pterin, thus forming the molybdenum cofactor (Moco) which is the active compound at the catalytic site of all other Mo-enzymes. (nih.gov)
- These enzymes require molybdopterin and FAD as cofactors and have and two 2FE-2S clusters. (embl.de)
- The molybdenum cofactor sulfurase ABA3 from Arabidopsis thaliana specifically regulates the activity of the molybdenum enzymes aldehyde oxidase and xanthine dehydrogenase by converting their molybdenum cofactor from the desulfo-form into the sulfo-form. (meta.org)
- In vitro, the NifS-like domain of ABA3 activates aldehyde oxidase and xanthine dehydrogenase in the absence of the C-terminal domain, but in vivo, the C-terminal domain is required for proper activation of both target enzymes. (meta.org)
- As expected, we found that the C. bescii genome contains genes necessary for the synthesis of the pyranopterin cofactor that coordinates molybdenum (Mo) in such enzymes ( 7 ). (asm.org)
- Xanthylic acid is an important metabolic intermediate in the Purine Metabolism, and is a product or substrate of the enzymes Inosine monophosphate dehydrogenase (EC 1.1.1.205), Hypoxanthine phosphoribosyltransferase (EC 2.4.2.8), Xanthine phosphoribosyltransferase (EC 2.4.2.22), 5'-Ribonucleotide phosphohydrolase (EC 3.1.3.5), Ap4A hydrolase (EC 3.6.1.17), Nucleoside-triphosphate diphosphatase (EC 3.6.1.19), Phosphoribosylamine-glycine ligase (EC 6.3.4.1), and glutamine amidotransferase (EC 6.3.5.2). (hmdb.ca)
- Manganese also serves as an important cofactor for many enzymes that catalyze carbohydrate, fat, and protein metabolism. (oregonstate.education)
Oxidoreductase9
- sulfite:ferricytochrome c oxidoreductase, EC 1.8.2.1) and xanthine dehydrogenase (xanthine:NAD+ oxidoreductase, EC 1.2.1.37) is described. (duke.edu)
- Xanthine oxidoreductase. (thefreedictionary.com)
- The thermodynamics of xanthine oxidoreductase catalysis. (thefreedictionary.com)
- Xanthine oxidase (XO, sometimes 'XAO') is a form of xanthine oxidoreductase, a type of enzyme that generates reactive oxygen species. (wikipedia.org)
- an oxidoreductase catalyzing the reaction of xanthine, O 2 , and H 2 O to produce urate and superoxide. (thefreedictionary.com)
- In vertebrates, aldehyde oxidases constitute the small sub-family of molybdo-flavoenzymes, along with the evolutionarily and structurally related protein, xanthine oxidoreductase. (nih.gov)
- Molybdenum cofactor functions directly in ethylbenzene dehydrogenase, glyceraldehyde-3-phosphate ferredoxin oxidoreductase, and respiratory arsenate reductase. (hmdb.ca)
- The molybdoflavoenzymes (MFEs), aldehyde oxidase (AOX) and xanthine oxidoreductase (XOR) catalyse the oxidation of many drugs, environmental pollutants and N-heterocyclic compounds. (hud.ac.uk)
- xanthine oxidoreductase ( XO) deficiency type I XO def. (symptoma.com)
Enzyme13
- The enzyme is a homodimer, and requires FAD, molybdenum and two 2FE-2S clusters as cofactors. (wikipedia.org)
- This activity is often found in a bifunctional enzyme with xanthine oxidase (EC 1.1.3.22) activity too. (wikipedia.org)
- The resulting loss of enzyme activity leads to buildup of certain chemicals, including sulfite, S-sulfocysteine, xanthine, and hypoxanthine (which can be identified in urine), and low levels of uric acid in the blood. (medlineplus.gov)
- In humans, molybdenum is a cofactor for three enzyme classes-sulfiteoxidase, aldehyde dehydrogenase, and xanthine oxidase (Kisker et al. (cdc.gov)
- Xanthine oxidase is defined as an enzyme activity (EC 1.17.3.2). (wikipedia.org)
- The molybdenum atoms are contained as molybdopterin cofactors and are the active sites of the enzyme. (wikipedia.org)
- Xanthine oxidase is a superoxide-producing enzyme found normally in serum and the lungs, and its activity is increased during influenza A infection. (wikipedia.org)
- Type II xanthinuria may result from a failure of the mechanism which inserts sulfur into the active sites of xanthine oxidase and aldehyde oxidase, a related enzyme with some overlapping activities (such as conversion of allopurinol to oxypurinol). (wikipedia.org)
- AOX is a dimer with a molecular mass of approximately 300 kDa, and each subunit of the homodimeric enzyme contains four different cofactors: the molybdenum cofactor, two distinct [2Fe-2S] clusters, and one FAD. (aspetjournals.org)
- Two inherited forms of xanthinuria principally result from a deficiency of the enzyme xanthine dehydrogenase, which is the enzyme responsible for degrading hypoxanthine and xanthine to uric acid. (medscape.com)
- Xanthine continues to accumulate, despite the recycling of hypoxanthine, because of the metabolism of guanine to xanthine by the enzyme guanase (see image below). (medscape.com)
- Type II xanthinuria is characterized by a deficiency of xanthine dehydrogenase and a related enzyme, aldehyde oxidase. (medscape.com)
- Zinc is a cofactor or constituent (metalloenzyme) for more than 100 enzyme systems in the animal body. (oregonstate.education)
Protein14
- Immunological examination of a biopsy sample of liver tissue revealed the presence of the xanthine dehydrogenase protein in near normal amounts. (duke.edu)
- The aldehyde oxidase and xanthine dehydrogenase, a/b hammerhead domain is an evolutionary conserved protein domain. (wikipedia.org)
- Although a tungsten-containing xanthine dehydrogenase from bacteria has been found to contain tungsten-molydopterin and also non-protein-bound selenium (thus removing the possibility of selenium in selenocysteine or selenomethionine form), a tungsten-selenium molybdopterin complex has not been definitively described. (wikipedia.org)
- Mutations in the MOCS1 , MOCS2 , or GPHN gene reduce or eliminate the function of the associated protein, which impairs molybdenum cofactor biosynthesis. (medlineplus.gov)
- Reiss J, Gross-Hardt S, Christensen E, Schmidt P, Mendel RR, Schwarz G. A mutation in the gene for the neurotransmitter receptor-clustering protein gephyrin causes a novel form of molybdenum cofactor deficiency. (medlineplus.gov)
- Nitrogenase MoFe-protein at 1.16 Å resolution: a central ligand in the FeMo-cofactor. (nature.com)
- A cofactor is any non-protein substance required for a protein to be catalytically active. (uniprot.org)
- MOCS1 (Molybdenum Cofactor Synthesis 1) is a Protein Coding gene. (genecards.org)
- The same protein, which in humans has the HGNC approved gene symbol XDH, can also have xanthine dehydrogenase activity (EC 1.17.1.4). (wikipedia.org)
- Most of the protein in the liver exists in a form with xanthine dehydrogenase activity, but it can be converted to xanthine oxidase by reversible sulfhydryl oxidation or by irreversible proteolytic modification. (wikipedia.org)
- Bovine xanthine oxidase (from milk) was originally thought to have a binding site to reduce cytochrome c with, but it has been found that the mechanism to reduce this protein is through XO's superoxide anion byproduct, with competitive inhibition by carbonic anhydrase. (wikipedia.org)
- The MOCS2 gene mutations involved in molybdenum cofactor deficiency likely eliminate the function of MOCS2A, MOCS2B, or both, although in rare cases that are less severe, some protein function may remain. (nih.gov)
- The protein contains a molybdopterin cofactor (Mo-co) and two different [2Fe-2S] centres. (embl.de)
- The protein binds a pyridoxal phosphate cofactor and a substrate-derived persulfide intermediate, and site-directed mutagenesis of strictly conserved binding sites for the cofactor and the persulfide demonstrated that they are essential for molybdenum cofactor sulfurase activity. (meta.org)
Xanthinuria8
- elevated in molybdenum cofactor deficiency and in xanthinuria. (thefreedictionary.com)
- Xanthinuria is a rare genetic disorder where the lack of xanthine oxidase leads to high concentration of xanthine in blood and can cause health problems such as renal failure. (wikipedia.org)
- Type I xanthinuria has been traced directly to mutations of the XDH gene which mediates xanthine oxidase activity. (wikipedia.org)
- An important gene associated with Xanthinuria is XDH (Xanthine Dehydrogenase), and among its related pathways/superpathways are Purine metabolism and Sulfur relay system . (malacards.org)
- 76 Xanthinuria, also known as xanthine oxidase deficiency, is a rare genetic disorder causing the. (malacards.org)
- Xanthinuria is a descriptive term for excess urinary excretion of the purine base xanthine. (medscape.com)
- Classic xanthinuria type I is the result of an isolated deficiency of xanthine dehydrogenase. (medscape.com)
- The other inherited form of xanthinuria, termed molybdenum cofactor deficiency, presents in the neonatal period with microcephaly, hyperreflexia, and other CNS manifestations. (medscape.com)
Patients with molybdenum cofactor deficiency2
- This gene is defective in patients with molybdenum cofactor deficiency, type A. A related pseudogene has been identified on chromosome 16. (genecards.org)
- A lower rate of oxidation is observed in patients with molybdenum cofactor deficiency. (thefreedictionary.com)
MOCS18
- Molybdenum cofactor deficiency is caused by mutations in the MOCS1 , MOCS2 , or GPHN gene. (medlineplus.gov)
- MOCS1 gene mutations cause type A, MOCS2 gene mutations cause type B, and GPHN gene mutations cause type C. The proteins produced from each of these genes are involved in the formation (biosynthesis) of a molecule called molybdenum cofactor. (medlineplus.gov)
- At least one individual with molybdenum cofactor deficiency inherited two mutated copies of the MOCS1 gene through a mechanism called uniparental isodisomy. (medlineplus.gov)
- Diseases associated with MOCS1 include Molybdenum Cofactor Deficiency, Complementation Group A and Molybdenum Cofactor Deficiency . (genecards.org)
- Mutations in the SUOX gene (sulfite oxidase) and in the component of the molybdenum cofactor ( MOCS1, MOCS2, MOCS3 , GEPH ) have been described. (medscape.com)
- Leimkühler S, Charcosset M, Latour P, Dorche C, Kleppe S, Scaglia F, Szymczak I, Schupp P, Hahnewald R, Reiss J. Ten novel mutations in the molybdenum cofactor genes MOCS1 and MOCS2 and in vitro characterization of a MOCS2 mutation that abolishes the binding ability of molybdopterin synthase. (nih.gov)
- Mutations in the molybdenum cofactor biosynthetic genes MOCS1, MOCS2, and GEPH. (nih.gov)
- This defect is caused by the mutation of molybdenum cofactor genes ( MOCS1 or MOCS2 ). (medscape.com)
Uric acid8
- Tests reveal that affected individuals have high levels of chemicals called sulfite, S-sulfocysteine, xanthine, and hypoxanthine in the urine and low levels of a chemical called uric acid in the blood. (medlineplus.gov)
- Catalyzes the conversion of hypoxanthine to xanthine and then to uric acid. (thefreedictionary.com)
- The following chemical reactions are catalyzed by xanthine oxidase: hypoxanthine + H2O + O2 ⇌ {\displaystyle \rightleftharpoons } xanthine + H2O2 xanthine + H2O + O2 ⇌ {\displaystyle \rightleftharpoons } uric acid + H2O2 Xanthine oxidase can also act on certain other purines, pterins, and aldehydes. (wikipedia.org)
- In the reaction with xanthine to form uric acid, an oxygen atom is transferred from molybdenum to xanthine, whereby several intermediates are assumed to be involved. (wikipedia.org)
- Because xanthine oxidase is a metabolic pathway for uric acid formation, the xanthine oxidase inhibitor allopurinol is used in the treatment of gout. (wikipedia.org)
- G], diagnosed as molybdenum cofactor deficiency type B. Neonatal seizures, progressive cerebral atrophy, and low serum levels of uric acid may provide diagnostic clues in patients with cerebral palsy of undetermined cause. (biomedsearch.com)
- Laboratory findings that are typically seen in molybdenum cofactor deficiency but not isolated sulfite oxidase deficiency include low or low-normal levels of plasma uric acid level (within reference range in individuals with isolated sulfite oxidase deficiency) and elevated levels of urinary xanthine and hypoxanthine (within reference range in individuals with sulfite oxidase deficiency). (medscape.com)
- Too much molybdenum can result in a gout-like syndrome, with increased blood levels of molybdenum, uric acid, and xanthine oxidase. (baycare.org)
Urate3
- Xanthine dehydrogenase (EC 1.1.1.204) catalyzes the hydrogenation of xanthine to urate, and also requires FAD, molybdenum and two 2FE-2S clusters as cofactors. (wikipedia.org)
- They include aldehyde oxidase ( EC 1.2.3.1 ), that converts an aldehyde and water to an acid and hydrogen peroxide, and xanthine dehydrogenase ( EC 1.1.1.204 ), that converts xanthine to urate. (embl.de)
- Xanthine + H(2)O + O(2) = urate + H(2)O(2). (ebi.ac.uk)
Member of the xanthine oxidase2
- Structural basis of periplasmic aldehyde oxidation in Escherichia coli , an exceptional member of the xanthine oxidase molybdoenzyme family, with an αβγ structure and an additional [4Fe-4S] cluster. (fu-berlin.de)
- The aldehyde oxido-reductase (Mop) from the sulphate reducing anaerobic Gram-negative bacterium Desulfovibrio gigas is a homodimer of 907 amino acid residues subunits and is a member of the xanthine oxidase family. (embl.de)
MOCS23
- Molybdenum Cofactor Deficiency - MOCS2 Related tests available. (bcm.edu)
- MOCS2 gene mutations cause a disorder called molybdenum cofactor deficiency. (nih.gov)
- 12 A molybdenum cofactor deficiency that has material basis in homozygous or compound heterozygous mutation in the MOCS2 gene on chromosome 5q11. (malacards.org)
Oxidoreductases2
- The unfolding and refolding of two multidomain oxidoreductases, bovine liver catalase and flavoprotein bovine milk xanthine oxidase (XO), have been analyzed by fluorescence spectroscopy, circular dichroism, and activity measurements. (scialert.net)
- These findings provide impetus for exploring the influences of cofactors such as FAD on the structure-function relationship of xanthine oxidoreductases. (scialert.net)
Component of the molybdenum cofactor1
- The pterin component of the molybdenum cofactor. (cbrc.jp)
Biosynthesis of the molybdenum cofactors1
- Leimkühler S., The biosynthesis of the molybdenum cofactors in Escherichia coli. (uni-potsdam.de)
Caused by molybdenum cofactor deficiency1
- Because of the serious health problems caused by molybdenum cofactor deficiency, affected individuals usually do not survive past early childhood. (medlineplus.gov)
Features of molybdenum cofactor deficiency2
- Researchers suggest that damage caused by the abnormally high levels of sulfite (and possibly other chemicals) leads to encephalopathy, seizures, and the other features of molybdenum cofactor deficiency. (medlineplus.gov)
- Clinical features of molybdenum cofactor deficiency, e.g., neonatal seizures, hypertonus/hypotonus, and feeding and respiratory difficulties, resemble those of neonatal hypoxic-ischemic encephalopathy. (biomedsearch.com)
Lacking the molybdenum cofactor1
- Inborn errors of molybdenum metabolism: combined deficiencies of sulfite oxidase and xanthine dehydrogenase in a patient lacking the molybdenum cofactor. (duke.edu)
Dehydrogenase and aldehyde oxidase2
- The distinction between the 2 types is based on the ability or inability to oxidize allopurinol, a substrate for xanthine dehydrogenase and aldehyde oxidase. (medscape.com)
- Xanthine dehydrogenase and aldehyde oxidase, but not sulfite oxidase and nitrate reductase, require the post-translational sulfuration of their Mo-site for becoming active. (nih.gov)
Deficiency of xanthine dehydrogenase2
- Five patients with a combined deficiency of xanthine dehydrogenase, sulphite oxidase and, possibly, also of aldehyde oxidase are described. (biomedsearch.com)
- Deficiency of xanthine dehydrogenase results in plasma accumulation and excess urinary excretion of the highly insoluble xanthine, which may lead to arthropathy, myopathy, crystal nephropathy, urolithiasis, or renal failure. (medscape.com)
Iron-molybdenum cofactor1
- Nature has developed two scaffolds holding molybdenum in place, the iron-molybdenum cofactor and pterin-based molybdenum cofactors. (nature.com)
Metabolism7
- Absence of hepatic molybdenum cofactor: an inborn error of metabolism leading to a combined deficiency of sulphite oxidase and xanthine dehydrogenase. (biomedsearch.com)
- The biosynthetic pathways leading to both types of cofactor have common mechanistic aspects relating to scaffold formation, metal activation and cofactor insertion into apoenzymes, and have served as an evolutionary 'toolbox' to mediate additional cellular functions in eukaryotic metabolism. (nature.com)
- The effect of ischemia/reperfusion on adenine nucleotide metabolism and xanthine oxidase production in skeletal muscle. (thefreedictionary.com)
- Among its related pathways are Metabolism and Metabolism of water-soluble vitamins and cofactors . (genecards.org)
- Since xanthine oxidase is involved in the metabolism of 6-mercaptopurine, caution should be taken before administering allopurinol and 6-mercaptopurine, or its prodrug azathioprine, in conjunction. (wikipedia.org)
- In the past decade, AOX has been recognized increasingly to play an important role in the metabolism of drugs through its complex cofactor content, tissue distribution, and substrate recognition. (aspetjournals.org)
- Manganese also functions as a cofactor in lipid metabolism through its role in cholesterol and fatty acid synthesis. (oregonstate.education)
Synthesis1
- 1964. A common co-factor for nitrate reductase and xanthine dehydrogenase which also regulates the synthesis of nitrate reductase. (asmscience.org)
Sulfite oxidase and xanthine1
- Characterization of di-(carboxamidomethyl)molybdopterin from sulfite oxidase and xanthine oxidase. (cbrc.jp)
Urinary5
- Further tests revealed elevated urinary levels of xanthine, hypoxanthine, and S-sulfocystein. (biomedsearch.com)
- Urinary urothion (a degradation product of molybdopterin), if low, is virtually diagnostic for molybdenum cofactor deficiency (except in cases of profound molybdenum deficiency). (medscape.com)
- An elevated urinary thiosulfate level is essentially diagnostic of sulfite oxidase deficiency or molybdenum cofactor deficiency. (medscape.com)
- 56 Molybdenum cofactor deficiency is a rare autosomal recessive metabolic disorder characterized by neonatal onset of intractable seizures, opisthotonus, and facial dysmorphism associated with hypouricemia and elevated urinary sulfite levels. (malacards.org)
- Inhibition of xanthine dehydrogenase by allopurinol may lead to accumulation and urinary excretion of xanthine. (medscape.com)
Aldehyde oxidase and xanthine1
- Aldehyde oxidase and xanthine dehydrogenase, a/b hammerhead domain Gordon AH, Green DE, Subrahmanyan V (May 1940). (wikipedia.org)
Binds2
- There is a 20 kDa N-terminal which binds to the two 2FE-2S cofactors, a 40 kDa domain which provides a means of binding to the FAD, and a C-terminal which houses the molybdenum. (wikipedia.org)
- Binds 1 Mo-molybdopterin (Mo-MPT) cofactor per subunit. (uniprot.org)
Sulfur1
- Sulfite oxidase catalyses the terminal reaction in the degradation of sulfur-containing amino acids, in which sulfite is oxidized to sulfate by means of a molybdenum cofactor and sulfite oxidase ( 1 ). (ajnr.org)
Genes1
- Molybdenum cofactor deficiency (MCD) is a group of autosomal recessive disorders due to mutations affecting the genes required for molybdenum cofactor biosynthesis. (endocrinologyadvisor.com)
Active molybdenum cofactor2
- however, hepatic content of molybdenum and the storage pool of active molybdenum cofactor present in normal livers were below the limits of detection. (duke.edu)
- The activity of SUOX depends on the presence of active molybdenum cofactor. (endocrinologyadvisor.com)
Nitrate1
- 1980. Characterization of the molybdenum cofactor of sulfite oxidase, xanthine, oxidase, and nitrate reductase. (asmscience.org)
Formation of xanthine2
- 12 A purine-pyrimidine metabolic disorder characterized by deficiency of xanthine oxidase, resulting in excretion of large amounts of xanthine in the urine and the formation of xanthine stones. (malacards.org)
- Kidney complications are initiated by the formation of xanthine crystals in the tubules, leading to parenchymal deposition and/or radiolucent stone formation. (medscape.com)
Metabolic1
- These types of disorders will show metabolic acidosis, ketosis, and/or hyperammonemia at time of mental status change, in contrast to molybdenum cofactor deficiciency. (endocrinologyadvisor.com)
Pathways1
- Here is a diagram highlighting the pathways catalyzed by xanthine oxidase. (wikipedia.org)
Gene1
- Mutations in the gene for sulfite oxidase ( SUOX ) produce a similar phenotype to that produced by molybdenum cofactor deficiency (MCD). (endocrinologyadvisor.com)
Pyranopterin-based1
- Figure 5: Biosynthesis of the pyranopterin-based molybdenum cofactors. (nature.com)
Bound1
- DMSO reductase, the metal is bound to two molybdopterin cofactors. (wikipedia.org)
Inhibition3
- Xanthine oxidase activity was expressed as percent inhibition of xanthine oxidase, calculated as (1 - B/A) x100, where A is the change in absorbance of the assay without the plant extract (Dabs. (thefreedictionary.com)
- 6 g) exhibited significant xanthine oxidase inhibition activity at 150 ug/ml as compared to the reference standard allopurinol 67. (thefreedictionary.com)
- Inhibition of xanthine oxidase has been proposed as a mechanism for improving cardiovascular health. (wikipedia.org)
Characterization1
- Mechanistic studies of human molybdopterin synthase reaction and characterization of mutants identified in group B patients of molybdenum cofactor deficiency. (nih.gov)
Oxidase revealed1
- Protonation state of MnFe and FeFe cofactors in a ligand binding oxidase revealed by X ray absorption, emission, and vibrational spectroscopy and QM/MM calculations. (fu-berlin.de)
Ligand1
- After molydopterin is eventually complexed with molybdenum, the complete ligand is usually called molybdenum cofactor. (wikipedia.org)
Pterin1
- Rajagopalan, K. V. & Johnson, J. L. The pterin molybdenum cofactors. (nature.com)
Escherichia1
- Reschke S, Duffus BR, Schrapers P, Mebs S, Teutloff C, Dau H, Haumann M, Leimkühler S. Identification of YdhV as the First Molybdoenzyme Binding a Bis-Mo-MPT Cofactor in Escherichia coli. (uni-potsdam.de)
Autosomal recessive1
- Molybdenum cofactor deficiency is a rare autosomal recessive disorder most often presenting with severe neonatal seizures. (endocrinologyadvisor.com)
Liver4
- The ultimate diagnosis was made by the measurement of 'molybdenum cofactor' in a liver biopsy specimen in three out of five patients. (biomedsearch.com)
- During severe liver damage, xanthine oxidase is released into the blood, so a blood assay for XO is a way to determine if liver damage has happened. (wikipedia.org)
- The native flavin, FAD, was removed from chicken liver xanthine dehydrogenase and milk xanthine oxidase by incubation with CaCl 2 . (elsevier.com)
- The flavin 6-position was also freely accessible to solvent in milk xanthine oxidase, but was significantly less exposed to solvent in the chicken liver dehydrogenase. (elsevier.com)
