Stereochemistry of the decarboxylation of glyoxylic acid by yeast pyruvate decarboxylase

Abstract

Tritiated glyoxylic acid was incubated with pyruvate decarboxylase. The hydroxymethylthiamine diphosphate formed was ozonolysed to give tritiated glycolic acid, the absolute configuration of which was investigated by analysis using glycolate oxidase. The tritiated glycolic acid proved to be racemic. The implications of this result are discussed in relation to models for the mechanism of pyruvate decarboxylase.