Enzymes
UniProtKB help_outline | 1,993 proteins |
Enzyme class help_outline |
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- Name help_outline L-gulono-1,4-lactone Identifier CHEBI:17587 (CAS: 1128-23-0) help_outline Charge 0 Formula C6H10O6 InChIKeyhelp_outline SXZYCXMUPBBULW-SKNVOMKLSA-N SMILEShelp_outline [H][C@@]1(OC(=O)[C@@H](O)[C@H]1O)[C@@H](O)CO 2D coordinates Mol file for the small molecule Search links Involved in 5 reaction(s) Find molecules that contain or resemble this structure Find proteins in UniProtKB for this molecule
- Name help_outline O2 Identifier CHEBI:15379 (CAS: 7782-44-7) help_outline Charge 0 Formula O2 InChIKeyhelp_outline MYMOFIZGZYHOMD-UHFFFAOYSA-N SMILEShelp_outline O=O 2D coordinates Mol file for the small molecule Search links Involved in 2,675 reaction(s) Find molecules that contain or resemble this structure Find proteins in UniProtKB for this molecule
- Name help_outline H+ Identifier CHEBI:15378 Charge 1 Formula H InChIKeyhelp_outline GPRLSGONYQIRFK-UHFFFAOYSA-N SMILEShelp_outline [H+] 2D coordinates Mol file for the small molecule Search links Involved in 9,331 reaction(s) Find molecules that contain or resemble this structure Find proteins in UniProtKB for this molecule
- Name help_outline H2O2 Identifier CHEBI:16240 (Beilstein: 3587191; CAS: 7722-84-1) help_outline Charge 0 Formula H2O2 InChIKeyhelp_outline MHAJPDPJQMAIIY-UHFFFAOYSA-N SMILEShelp_outline [H]OO[H] 2D coordinates Mol file for the small molecule Search links Involved in 437 reaction(s) Find molecules that contain or resemble this structure Find proteins in UniProtKB for this molecule
- Name help_outline L-ascorbate Identifier CHEBI:38290 (Beilstein: 3549814; CAS: 299-36-5) help_outline Charge -1 Formula C6H7O6 InChIKeyhelp_outline CIWBSHSKHKDKBQ-JLAZNSOCSA-M SMILEShelp_outline [H][C@@]1(OC(=O)C(O)=C1[O-])[C@@H](O)CO 2D coordinates Mol file for the small molecule Search links Involved in 34 reaction(s) Find molecules that contain or resemble this structure Find proteins in UniProtKB for this molecule
Cross-references
RHEA:32363 | RHEA:32364 | RHEA:32365 | RHEA:32366 | |
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Reaction direction help_outline | undefined | left-to-right | right-to-left | bidirectional |
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Publications
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Purification and characterization of L-gulonolactone oxidase from chicken kidney microsomes.
Kiuchi K., Nishikimi M., Yagi K.
Biochemistry 21:5076-5082(1982) [PubMed] [EuropePMC]
This publication is cited by 2 other entries.
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Functional rescue of vitamin C synthesis deficiency in human cells using adenoviral-based expression of murine l-gulono-gamma-lactone oxidase.
Ha M.N., Graham F.L., D'Souza C.K., Muller W.J., Igdoura S.A., Schellhorn H.E.
l-Gulono-gamma-lactone oxidase (GULO) is a critical enzyme present in most mammalian species that is required for the terminal step in vitamin C biosynthesis. Primates are absolutely dependent on exogenously supplied dietary vitamin C due to inactivation of the Gulo gene by mutation over 40 millio ... >> More
l-Gulono-gamma-lactone oxidase (GULO) is a critical enzyme present in most mammalian species that is required for the terminal step in vitamin C biosynthesis. Primates are absolutely dependent on exogenously supplied dietary vitamin C due to inactivation of the Gulo gene by mutation over 40 million years ago. In this study, we report the cloning and expression of the murine l-gulono-gamma-lactone oxidase cDNA and gene. The cDNA (2.3 kb) encodes an open reading frame of 440 amino acids that shows high homology to the rat l-gulono-gamma-lactone oxidase (>94%). The Gulo gene is 22 kb long and contains 12 exons. The 11 introns range in size from 479 to 5641 bp. Northern blot analysis revealed high expression of Gulo transcript in the liver. To investigate whether metabolic loss of vitamin C biosynthesis in human cells can be corrected by heterologous expression of GULO, we constructed a first-generation adenoviral vector expressing the murine GULO cDNA under the transcriptional control of the murine cytomegalovirus (MCMV) early promoter. Low rescue efficiency of Gulo-expressing adenoviral constructs and reduced viral growth in HEK293 cells were observed, suggesting that overexpression of Gulo may be inhibitory to cell growth. Placement of a removable stuffer fragment flanked by lox sites between the MCMV promoter and the Gulo gene resulted in efficient vector rescue and normal viral replication in parental HEK293 cells and high-level expression of Gulo in HEK293 cells expressing Cre recombinase. Cells infected with Gulo-expressing vectors overexpressed an FAD-containing protein that corresponded in size to that predicted for recombinant GULO protein and expressed a functional enzyme as measured by the conversion of l-gulono-gamma-lactone to ascorbic acid in cell-free extracts. The cloning of the murine Gulo cDNA and the construction of Gulo-expressing adenoviral vectors are vital steps toward determining the role of vitamin C in basic metabolism and in disease. << Less
Genomics 83:482-492(2004) [PubMed] [EuropePMC]
This publication is cited by 2 other entries.
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Characterisation of D-arabinono-1,4-lactone oxidase from Candida albicans ATCC 10231.
Huh W.K., Kim S.T., Yang K.S., Seok Y.J., Hah Y.C., Kang S.O.
D-Erythroascorbic acid was detected from the cell extracts of a dimorphic fungus, Candida albicans. Its concentration in yeast cells grown at 25 degrees C was estimated to be about 0.45 mumol/ml cell water. D-Arabinono-1,4-lactone oxidase, which catalyses the final step in the biosynthesis of D-er ... >> More
D-Erythroascorbic acid was detected from the cell extracts of a dimorphic fungus, Candida albicans. Its concentration in yeast cells grown at 25 degrees C was estimated to be about 0.45 mumol/ml cell water. D-Arabinono-1,4-lactone oxidase, which catalyses the final step in the biosynthesis of D-erythroascorbic acid, was purified 639-fold from the mitochondrial fraction of C. albicans to apparent homogeneity, with an overall yield of 21.2%, by a purification procedure consisting of Triton X-100 solubilisation, ammonium sulphate precipitation, anion-exchange, hydrophobic-interaction, gel-filtration and dye-ligand chromatographies. Gel-filtration chromatography and polyacrylamide-gradient gel electrophoresis in the presence of deoxycholate gave apparent molecular masses of 110 kDa and 84.4 kDa, respectively. SDS/PAGE showed only one protein band corresponding to a molecular mass of 66.7 kDa. Considering the binding of detergents, the enzyme is suggested to be a single polypeptide. The enzyme showed a typical fluorescence excitation spectrum of a flavin-containing enzyme. The flavin was not released by treatment with SDS, CCl3CO2H or boiling, indicating that it may be covalently bound to the enzyme protein. The enzyme was optimally active at 40 degrees C and at pH 6.1. The enzyme was stable in the range pH 7.5-10. An apparent Km value for D-arabinono-1,4-lactone was 44.1 mM. L-Galactono-1,4-lactone, L-gulono-1,4-lactone and L-xylono-1,4-lactone could also serve as substrates. Competitive inhibition was demonstrated with D-glucono-1,5-lactone, L-arabinono-1,4-lactone, D-galactono-1,4-lactone and D-gulono-1,4-lactone. p-Chloromercuribenzoate, N-ethylmaleimide, iodoacetic acid, iodoacetamide and divalent metal ions such as Cd2+, Hg2+, Mn2+ and Zn2+ exhibited inhibitory effects on the enzyme. << Less
Eur. J. Biochem. 225:1073-1079(1994) [PubMed] [EuropePMC]
This publication is cited by 3 other entries.
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Induction and peroxisomal appearance of gulonolactone oxidase upon clofibrate treatment in mouse liver.
Braun L., Mile V., Schaff Z., Csala M., Kardon T., Mandl J., Banhegyi G.
Various antihyperlipemic peroxisome proliferators are known to be carcinogenic in rodents but not in human, other primates and guinea pig, which species lost their ability to synthesize ascorbate due to mutations in the gulonolactone oxidase gene. Ascorbate synthesis is accompanied by H2O2 product ... >> More
Various antihyperlipemic peroxisome proliferators are known to be carcinogenic in rodents but not in human, other primates and guinea pig, which species lost their ability to synthesize ascorbate due to mutations in the gulonolactone oxidase gene. Ascorbate synthesis is accompanied by H2O2 production, consequently its induction can be potentially harmful; therefore, the in vivo effect of the peroxisome proliferator clofibrate was investigated on gulonolactone oxidase expression in mouse liver. Liver weights and peroxisomal protein contents were increased upon clofibrate treatment. Elevated plasma ascorbate concentrations were found in clofibrate-treated mice due to the higher microsomal gulonolactone oxidase activities. Remarkable gulonolactone oxidase activity appeared in the peroxisomal fraction upon the treatment. Increased activity of the enzyme was associated with an elevation of its mRNA level. According to the present results the evolutionary loss of gulonolactone oxidase may contribute to the explanation of the missing carcinogenic effect of peroxisome proliferators in humans. << Less
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Synthesis of L-ascorbic acid in rat-liver homogenates. Conversion of L-gulono- and L-galactono-gamma-lactone and the respective acids into L-ascorbic acid.
ISHERWOOD F.A., MAPSON L.W., CHEN Y.T.
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The contribution of Arabidopsis homologs of L-gulono-1,4-lactone oxidase to the biosynthesis of ascorbic acid.
Maruta T., Ichikawa Y., Mieda T., Takeda T., Tamoi M., Yabuta Y., Ishikawa T., Shigeoka S.
To clarify the involvement of seven Arabidopsis homologs of rat L-gulono-1,4-lactone (L-GulL) oxidase, AtGulLOs, in the biosynthesis of L-ascorbic acid (AsA), transgenic tobacco cells overexpressing the various AtGulLOs were generated. Under treatment with L-GulL, the levels of total AsA in three ... >> More
To clarify the involvement of seven Arabidopsis homologs of rat L-gulono-1,4-lactone (L-GulL) oxidase, AtGulLOs, in the biosynthesis of L-ascorbic acid (AsA), transgenic tobacco cells overexpressing the various AtGulLOs were generated. Under treatment with L-GulL, the levels of total AsA in three transgenic tobacco cell lines, overexpressing AtGulLO2, 3, or 5, were significantly increased as compared with those in control cells. << Less
Biosci. Biotechnol. Biochem. 74:1494-1497(2010) [PubMed] [EuropePMC]
This publication is cited by 2 other entries.
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Cloning and chromosomal mapping of the human nonfunctional gene for L-gulono-gamma-lactone oxidase, the enzyme for L-ascorbic acid biosynthesis missing in man.
Nishikimi M., Fukuyama R., Minoshima S., Shimizu N., Yagi K.
Man is among the exceptional higher animals that are unable to synthesize L-ascorbic acid because of their deficiency in L-gulono-gamma-lactone oxidase, the enzyme catalyzing the terminal step in L-ascorbic acid biosynthesis. In the present study, we isolated a segment of the nonfunctional L-gulon ... >> More
Man is among the exceptional higher animals that are unable to synthesize L-ascorbic acid because of their deficiency in L-gulono-gamma-lactone oxidase, the enzyme catalyzing the terminal step in L-ascorbic acid biosynthesis. In the present study, we isolated a segment of the nonfunctional L-gulono-gamma-lactone oxidase gene from a human genomic library, and mapped it on chromosome 8p21.1 by spot blot hybridization using flow-sorted human chromosomes and fluorescence in situ hybridization. Sequencing analysis indicated that the isolated segment represented a 3'-part of the gene, where the regions corresponding to exons VII, IX, X, and XII of the rat L-gulono-gamma-lactone oxidase gene remain with probable deletion of the regions corresponding to exons VIII and XI. In the identified exon regions were found various anomalous nucleotide changes, such as deletion and insertion of nucleotide(s) and nonconformance to the GT/AG rule at intron/exon boundaries. When the conceptual amino acid sequences deduced from the four exon sequences were compared with the corresponding rat sequences, there were a large number of nonconservative substitutions and also two stop codons. These findings indicate that the human nonfunctional L-gulono-gamma-lactone oxidase gene has accumulated a large number of mutations without selective pressure since it ceased to function during evolution. << Less
J Biol Chem 269:13685-13688(1994) [PubMed] [EuropePMC]
This publication is cited by 2 other entries.
Comments
Multi-step reaction: RHEA:12352 + RHEA:15269.