Acetate Formate and Related Enzymes as Factors in Metabolism

摘要

1. Homogenates of the larvae of Phormia reqina (Meig.) oxidize formate to carbon dioxide.n2. The formate oxidizing enzyme was purified about eighteen-fold, and simultaneously a similar purification of catalase was obtained.n3. Formate oxidation is competitively inhibited by nitrite and ethanol and is oxidized by a catalase-peroxide complex.n4. Hydrogen peroxide is generated by oxidation of reduced sulfhydryls like glutathipne and homocysteine. I£ is also produced by the oxidation of hypoxanthine by xanthine oxidase, NADH2 and NADPH2+ through flavins, and possibly folate.n5. Thus formate oxidation in Phormia involves coupled re¬actions between enzyme systems producing hydrogen peroxide (except glutathione oxidation if it is a non-enzymatic reaction) to form a complex with catalase, which in turn oxidizes formate to carbon dioxide.n6. If Phormia reqina is grown on a diet in which carnitine replaces choline, then a new phosphatid, phosphatidyl methylcholine is made.