Reaction: thiamine + 2 O2 + H2O = thiamine acetic acid + 2 H2O2
Other name(s): thiamin dehydrogenase; thiamine dehydrogenase; thiamin:oxygen 5-oxidoreductase
Systematic name: thiamine:oxygen 5-oxidoreductase
Comments: A flavoprotein (FAD). The product differs from thiamine in replacement of -CH2.CH2.OH by -CH2.COOH; the two-step oxidation proceeds without the release of the intermediate aldehyde from the enzyme.
Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, CAS registry number: 96779-44-1
References:
1. Edmondson, D.E., Kenney, W.C. and Singer, T.P. Structural elucidation and properties of 8α-(N1-histidyl)riboflavin: the flavin component of thiamine dehydrogenase and β-cyclopiazonate oxidocyclase. Biochemistry 15 (1976) 2937-2945. [PMID: 8076]
2. Gomez-Moreno, C. and Edmondson, D.E. Evidence for an aldehyde intermediate in the catalytic mechanism of thiamine oxidase. Arch. Biochem. Biophys. 239 (1985) 46-52. [PMID: 2988447]
3. Neal, R.A. Bacterial metabolism of thiamine. 3. Metabolism of thiamine to 3-(2'-methyl-4'-amino-5'-pyrimidylmethyl)-4-methyl-thiazole-5-acetic acid (thiamine acetic acid) by a flavoprotein isolated from a soil microorganism. J. Biol. Chem. 245 (1970) 2599-2604. [PMID: 4987737]