Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: KEGG:D02011 (FAD)
 5,530 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

An inducible membrane-bound L-4-hydroxymandelate oxidase (decarboxylating) from Pseudomonas convexa has been solubilized and partially purified. It catalyzes the conversion of L-4-hydroxymandelic acid to 4-hydroxybenzaldehyde in a single step with the stoichiometric consumption of O2 and liberation of CO2. The enzyme is optimally active at pH 6.6 and at 55 degrees C. It requires FAD and Mn2+ for its activity. The membrane-bound enzyme is more stable than the solubilized and purified enzyme. After solubilization it gradually loses its activity when kept at 5 degrees C which can be fully reactivated by freezing and thawing. The Km values for DL-4-hydroxymandelate and FAD are 0.44 mM and 0.038 mM respectively. The enzyme is highly specific for DL-4-hydroxymandelic acid. DL-3,4-Dihydroxymandelic acid competitively inhibited the enzyme reaction. From the Dixon plot the Ki for DL-3,4-dihydroxymandelic acid was calculated to be 1.8 X 10(-4) M. The enzyme is completely inactivated by thiol compounds and not affected by thiol inhibitors. The enzyme is also inhibited by denaturing agents, heavy metal ions and by chelating agents.
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PMID:Purification and properties of L-4-hydroxymandelate oxidase from Pseudomonas convexa. 97 59

A monoclonal antibody (mAb, A) recognizing the FAD-binding domain of 4-aminobenzoate hydroxylase (4-aminobenzoate, NAD(P)H:oxygen oxidoreductase (1-hydroxylating, decarboxylating), EC 1.14.13.27) from Agaricus bisporus, a common edible mushroom, had been produced (Tsuji, H., Ogawa, T., Bando, N., Kimoto, M. and Sasaoka, K. (1990) J. Biol. Chem. 265, 16064-16067). In the present study, three other mAbs (B1, B2 and B3) against the enzyme have been further prepared in order to facilitate the structural characterization of the enzyme. The three new mAbs immunoblotted the enzyme. The four mAbs, including A, were specific for different epitopes on the enzyme. B1 and B2 immunoprecipitated the apoenzyme and the immunoprecipitation was inhibited in the presence of FAD, whereas B3 failed to immunoprecipitate the apoenzyme in the absence or presence of FAD. B1 and B2 competed with FAD for the binding to the apoenzyme. These findings show that B1 and B2 recognize the FAD-binding domain of the enzyme in analogy with A. The immunoblotting analyses of the peptides obtained from the enzyme by digestion with lysyl endopeptidase (EC 3.4.21.50) provided useful knowledge as to the location of the epitopes to the mAbs on the enzyme, suggesting that the FAD-binding domain of the enzyme can be located and characterized by detailed investigations on the location of the epitopes.
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PMID:Preparation and characterization of monoclonal antibodies against 4-aminobenzoate hydroxylase from Agaricus bisporus. 137 Dec 28

Homology analyses of the protein sequences of chicken liver and rat mammary gland fatty acid synthases [acyl-CoA:malonyl-CoA C-acyltransferase (decarboxylating, oxoacyl- and enoyl-reducing and thioester hydrolyzing), EC 2.3.1.85] and yeast fatty acid synthase [fatty-acyl-CoA synthase; acyl-CoA:malonyl-CoA C-acyltransferase (decarboxylating, oxoacyl- and enoyl-reducing), EC 2.3.1.86] were carried out. The amino acid sequences of the chicken and rat enzymes are 67% identical. If conservative substitutions are allowed, 78% of the amino acids are matched. A region of low homologies exists between the functional domains, in particular around amino acid residues 1059-1264 of the chicken enzyme. Homologies between the active sites of chicken and rat and of chicken and yeast enzymes have been analyzed by an alignment method. A high degree of homology exists between the active sites of the chicken and rat enzymes. However, the chicken and yeast enzymes show a lower degree of homology. The NADPH-binding dinucleotide folds of the beta-ketoacyl reductase and the enoyl reductase sites were identified by comparison with a known consensus sequence for the NADP- and FAD-binding dinucleotide folds. The active sites of all of the enzymes are primarily in hydrophobic regions of the protein. This study suggests that the genes for the functional domains of fatty acid synthase were originally separated, and these genes were connected to each other by using different connecting nucleotide sequences in different species. An alternative explanation for the differences in rat and chicken is a common ancestry and mutations in the joining regions during evolution. A higher mutation rate in the joining regions than in the active site regions of the enzymes without loss of function might be expected.
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PMID:Homology analysis of the protein sequences of fatty acid synthases from chicken liver, rat mammary gland, and yeast. 268 49

The activities of the mitochondrial enzymes citrate synthase (citrate oxaloacetatelyase, EC 4.1.3.7), NADP-linked isocitrate dehydrogenase (threo-Ds-isocitrate:NADP+ oxidoreductase (decarboxylating), EC 1.1.1.42), and succinate dehydrogenase (succinate: FAD oxidoreductase, EC 1.3.99.1) as well as their kinetic behavior in the two developmental forms of Trypanosoma cruzi at insect vector stage, epimastigotes and infective metacyclic trypomastigotes, were studied. The results presented in this work clearly demonstrate a higher mitochondrial metabolism in the metacyclic forms as is shown by the extraordinary enhanced activities of metacyclic citrate synthase, isocitrate dehydrogenase, and succinate dehydrogenase. In epimastigotes, the specific activities of citrate synthase at variable concentrations of oxalacetate and acetyl-CoA were 24.6 and 26.6 mU/mg of protein, respectively, and the Michaelis constants were 7.88 and 6.84 microM for both substrates. The metacyclic enzyme exhibited the following kinetic parameters: a specific activity of 228.4 mU/mg and Km of 3.18 microM for oxalacetate and 248.5 mU/mg and 2.75 microM, respectively, for acetyl-CoA. NADP-linked isocitrate dehydrogenase specific activities for epimastigotes and metacyclics were 110.2 and 210.3 mU/mg, whereas the apparent Km's were 47.9 and 12.5 microM, respectively. No activity for the NAD-dependent isozyme was found in any form of T. cruzi differentiation. The particulated succinate dehydrogenase showed specific activities of 8.2 and 39.1 mU/mg for epimastigotes and metacyclic trypomastigotes, respectively, although no significant changes in the Km (0.46 and 0.48 mM) were found. The cellular role and the molecular mechanism that probably take place during this significant shift in the mitochondrial metabolism during the T. cruzi differentiation have been discussed.
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PMID:Differential energetic metabolism during Trypanosoma cruzi differentiation. I. Citrate synthase, NADP-isocitrate dehydrogenase, and succinate dehydrogenase. 305 38

Pseudomonas L-phenylalanine oxidase (deaminating and decarboxylating) contains two FAD molecules in one molecule of the enzyme (Koyama, H. (1983) J. Biochem. 93, 1313-1319). When the enzyme was mixed anaerobically with L-phenylalanine, beta-2-thienylalanine, L-tyrosine, or L-methionine, a spectral species (purple intermediate) with a broad absorption band around 540 nm was observed with each substrate, and decayed slowly. From the data on the overall reaction kinetics, the rate of the L-phenylalanine oxidase reaction was expressed as follows. e/v = e/Vm + A/[S] + B/[O2] where e represents the concentration of enzyme unit, v the rate of the overall reaction, Vm the maximum velocity, and A and B are constants. Furthermore, the reactions of the enzyme with beta-2-thienylalanine (mostly an oxygenase substrate) and L-methionine (an oxidase substrate) were analyzed by the "stopped flow" method. The following scheme for the mechanism of L-phenylalanine oxidase reaction with both substrates is proposed, based on the data obtained. (formula; see text) Where Eox represents the oxidized form of the enzyme unit, EoxS the enzyme unit (oxidized form)-substrate compound, X the purple intermediate with a characteristic broad absorption band around 540 nm, S the substrate and P the product.
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PMID:Spectral and kinetic studies on Pseudomonas L-phenylalanine oxidase (deaminating and decarboxylating). 381 66

A novel activity producing gamma-aminobutyric acid (GABA) from L-ornithine in the presence of NAD(P)+ was found in the crude extract of L-ornithine-induced Hafnia alvei, in addition to L-ornithine decarboxylase (ODC) activity. The reaction system for the former activity consisted of two enzymes, L-ornithine oxidase (decarboxylating, OOD) and gamma-aminobutyraldehyde (GABL) dehydrogenase (GDH). OOD catalyzed the conversion of L-ornithine into GABL, CO2, NH3, and H2O2 in the presence of O2, and GDH dehydrogenated GABL to GABA in the presence of NAD(P)+. OOD, purified to homogeneity, had a high ODC activity and the activity ratio of ODC to OOD was almost constant throughout the purification (ODC/ OOD=160:1). The molecular mass of the OOD was about 230 kDa, probably consisting of three identical subunits of a 77 kDa peptide, and OOD had an absorption maximum at 420 nm as well as at 278 nm, the specific absorption for an enzyme containing pyridoxal phosphate (PLP). The content of PLP was estimated at about 1 mol per subunit. OOD was specific to L-ornithine, and other L-amino acids and polyamines including putrescine were inert. The enzyme was activated by PLP, but not by pyridoxamine 5'-phosphate, FAD, FMN, or pyrroloquinoline quinone, and it was inactivated by hydrazine, semicarbazide, and hydroxylamine. The holoenzyme can be resolved to the apoenzyme by incubation with hydroxylamine, and reconstituted with PLP. These properties of OOD were almost the same as those of ODC separately purified to homogeneity from H. alvei. Zn2+ and Cu2+, butanedione, and sodium borohydride inhibited both OOD and ODC in a similar manner. The OOD reaction required O2 and only the ODC reaction proceeded under anaerobic conditions. The substitution of air for oxygen in the reaction vessel and the addition of catalase-H2O, enhanced only the OOD reaction, resulting in an increase of the ratio of OOD/ODC to 1:30 and 1:4.1, respectively. These results suggested that OOD and ODC are identical and that the former is a side reaction of the latter in the presence of O2.
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PMID:L-ornithine decarboxylase from Hafnia alvei has a novel L-ornithine oxidase activity. 944 11

A basidiomycete, Coprinus sp. SF-1, was found to produce an L-Trp-oxidizing enzyme by screening from the culture collection of our laboratory. After solubilization by 1 M NaSCN from the particulate fraction of disrupted cells of the strain, the enzyme was purified about 76-fold to essential homogeneity. The enzyme had a molecular mass of about 420 kDa and the subunit molecular mass was 68 kDa. The enzyme contained 1 mol of non-covalently bound FAD per mol of the subunit. It catalyzed the simultaneous reactions of oxidative deamination and oxygenative decarboxylation of L-Trp to form indolepyruvic acid and indole-3-acetamide, the former of which was further oxidized to indole-3-acetic acid. The molar ratio of the respective reaction products was about 9:1. The enzyme specifically oxidized L-Trp, and slightly acted on L-Phe and L-Tyr. The Km for L-Trp was about 0.5 mM in both oxidase and oxygenase reactions. Thus, the enzyme is a novel one and was tentatively designated "L-Trp oxidase (deaminating and decarboxylating)". The optimum pHs of oxidase and oxygenase activities were 7.0 and 9.0, respectively. The optimum temperatures of both activities were 50 degrees C. The enzyme was stable at pH 6.0-10.5 and below 50 degrees C, and at 4 degrees C for 1 year.
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PMID:A novel enzyme, L-tryptophan oxidase, from a basidiomycete, Coprinus sp. SF-1: purification and characterization. 1094 68

The nucleotide sequence encoding L-phenylalanine oxidase (deaminating and decarboxylating) (PAO) from Pseudomonas sp. P-501 was determined. The open reading frame is arranged in the order of prosequence, alpha subunit, dipeptide and beta subunit from the 5'- to 3'-end. Expression of the gene in Escherichia coli showed that without the prosequence, PAO is produced in small quantity as a soluble form with no visible absorption, but with the prosequence (proPAO), PAO is highly expressed and yellow. The purified proPAO contained one mol of FAD per mol of proPAO polypeptide, but had no catalytic activity. Treatment of proPAO with a mixture of Pronase and trypsin converted the noncatalytic proPAO to the catalytic form, and the Pronase-trypsin-treated proPAO showed kinetic and spectral properties comparable to the native enzyme. These results suggest that in Pseudomonas, PAO is expressed as a proenzyme that is processed by proteolysis to the active form.
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PMID:Sequencing and expression of the L-phenylalanine oxidase gene from Pseudomonas sp. P-501. Proteolytic activation of the proenzyme. 1563 1

Pseudomonas L-phenylalanine oxidase (deaminating and decarboxylating) mainly catalyzes oxygenation when L-phenylalanine is used as the substrate, but oxidation when L-methionine is used as the substrate. Using [C(alpha)-H]-DL-methionine and [C(alpha)-D]-DL-methionine as substrate, the reductive half reaction of FAD cofactor of enzyme has been studied by stopped-flow spectrophotometry. The rate of reduction of FAD cofactor has a kinetic isotope effect (KIE) of 5.4 and 4.1 in the absence and presence of 30% glycerol, respectively. The KIE is independent of temperature, but the rates of the reductive half reaction are dependent on temperature, indicating that thermally induced motion at the active site drives the H-transfer reaction by H-tunneling.
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PMID:Kinetic isotope effect of the L-phenylalanine oxidase from Pseudomonas sp. P-501. 1656 20