Abstract
Enzymatic properties of S-carbalkoxythiamine (CAT) metabolizing factor partially purified from rabbit liver has been investigated. The factor was stable for at least 20 minutes at 50℃, while it was completely inactivated within 2 minutes at 100℃. Optimal pH for S-carbobutoxythiamine metabolism was around 7.5,but in case of O, S-dicarbethoxythiamine, the higher the pH, the more the thiamine produced. The activity was inhibited by eserine, neostigmine and heavy metal ions such as Hg^<2+> and Cu^<2+>. The final reaction products of CAT with this factor were identified as thiamine, carbon dioxide and alcohol corresponded to the alkoxy radical of CAT, so that this metabolic reaction was considered to be a hydrolytic reaction accompanied by decarboxylation, and the catalytic factor for this reaction should be classified as a hydrolase.
