Enzymes
UniProtKB help_outline | 3 proteins |
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Reaction participants Show >> << Hide
- Name help_outline A Identifier CHEBI:13193 Charge Formula R SMILEShelp_outline * 2D coordinates Mol file for the small molecule Search links Involved in 2,783 reaction(s) Find molecules that contain or resemble this structure Find proteins in UniProtKB for this molecule
- Name help_outline β-cyclopiazonate Identifier CHEBI:58067 Charge -1 Formula C20H21N2O3 InChIKeyhelp_outline HLDTVPRYVAHRIQ-BQGMYUGNSA-M SMILEShelp_outline [H][C@@]1(Cc2c[nH]c3cccc(CC=C(C)C)c23)NC(=O)\C(C1=O)=C(\C)[O-] 2D coordinates Mol file for the small molecule Search links Involved in 2 reaction(s) Find molecules that contain or resemble this structure Find proteins in UniProtKB for this molecule
- Name help_outline AH2 Identifier CHEBI:17499 Charge 0 Formula RH2 SMILEShelp_outline *([H])[H] 2D coordinates Mol file for the small molecule Search links Involved in 2,713 reaction(s) Find molecules that contain or resemble this structure Find proteins in UniProtKB for this molecule
- Name help_outline α-cyclopiazonate Identifier CHEBI:58256 Charge -1 Formula C20H19N2O3 InChIKeyhelp_outline CNZIQHGDUXRUJS-PTNHGACKSA-M SMILEShelp_outline [H][C@@]12N(C(=O)\C(C1=O)=C(\C)[O-])C(C)(C)[C@]1([H])Cc3cccc4[nH]cc(c34)[C@]21[H] 2D coordinates Mol file for the small molecule Search links Involved in 1 reaction(s) Find molecules that contain or resemble this structure Find proteins in UniProtKB for this molecule
Cross-references
RHEA:14525 | RHEA:14526 | RHEA:14527 | RHEA:14528 | |
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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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-cyclopiazonate oxidocyclase from Penicillium cyclopium. II. Studies on electron acceptors, inhibitors, enzyme kinetics, amino acid composition, flavin prosthetic group and other properties.
Schabort J.C., Potgeiter D.J.
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Structural elucidation and properties of 8alpha-(N1-histidyl)riboflavin: the flavin component of thiamine dehydrogenase and beta-cyclopiazonate oxidocyclase.
Edmondson D.E., Kenney W.C., Singer T.P.
In addition to 8alpha-(N3-histidyl)riboflavin, 8alpha-(N1-histidyl)riboflavin is also formed during the reaction of Nalpha-blocked histidine with 8alpha-bromotetraacetylriboflavin in a yield of 20-25% of the total histidylflavin fraction. The properties of 8alpha-(N1-histidyl)riboflavin are inditi ... >> More
In addition to 8alpha-(N3-histidyl)riboflavin, 8alpha-(N1-histidyl)riboflavin is also formed during the reaction of Nalpha-blocked histidine with 8alpha-bromotetraacetylriboflavin in a yield of 20-25% of the total histidylflavin fraction. The properties of 8alpha-(N1-histidyl)riboflavin are inditical with those of the histidylflavin isolated from thiamine dehydrogenase and beta-cyclopiazonate oxidocyclase but differ from those of 8alpha-(N3-histidyl)riboflavin. These properties include pKa of fluorescence quenching, electrophoretic mobility at pH 5.0, stability to storage, and reduction by NaBH4. Proof for 8alpha substitution is shown by the electron paramagnetic resonance and electron-nuclear double resonance spectra of the cationic semiquinone form, as well as by the proton magnetic resonance spectrum of the oxidized form. The site of histidine substitution by the 8alpha-methylene of the flavin moiety was shown by methylation of the imidazole ring with methyl iodide, cleavage of the methylhistidine-flavin bond by acid hydrolysis at 150 degrees C, and identification of the methylhistidine isomer by electrophoresis. 3-Methylhistidine is the product from the N1-histidylflavin isomer, while 1-methylhistidine is produced from the N3 isomer. The flavin product from reductive Zn cleavage of either isomer has been identified as riboflavin. The compound obtained on acid treatment of 8alpha-(N3-histidyl)riboflavin (previously thought to be the N1 isomer) differs from the parent compound only in the ribityl side chain, since chemical degradation studies show 1-methylhistidine as a product and a flavin product which differs from riboflavin only in mobility in thin-layer chromatography, but not in absorption, fluorescence, and electron paramagnetic resonance spectral properties. Proof that acid modification involves only the ribityl chain has come from the observations that alkaline irradiation of this flavin yields lumiflavin, that the proton magnetic resonance spectrum of the compound differs from that of riboflavin in the region of the ribityl proton resonance, and that its periodate titer is lower than that of authentic riboflavin. The identity of 8alpha-(N1-histidyl)riboflavin with the histidylflavin from thiamine dehydrogenase and beta-cyclopiazonate oxidocyclase shows that both isomeric forms of 8alpha-histidylflavin occur in nature. << Less
Biochemistry 15:2937-2945(1976) [PubMed] [EuropePMC]
This publication is cited by 1 other entry.