Triosephosphate dehydrogenase of Bacterium coli

Abstract

A cell-free extract of Bact. coli containing zymohexase and phosphoglyceraldehyde dehydrogenase was made. As coenzyme I and either inorganic phosphate or arsenate was required for the oxidation, the following course of reaction was assumed in the presence of NaF; 3-phosphoglyceraldehyde [forward arrow] 1:3-diphosphoglyceraldehyde [forward arrow] 1:3-diphosphoglyceric acid [forward arrow] 3-phosphoglyceric acid. The oxidation was reversible with respect to the reduction and oxidation of coenzyme I. Iodoacetate inhibited the oxidation. Malic acid dehydrogenase was also present in the extract and the triosephosphate was oxidised by oxalacetic acid in a coenzyme-linked reaction. The prep. also dismuted phosphoglyceraldehyde slowly.