Further Characterization of Glycolaldehyde Dehydrogenase Isozymes from Escherichia coli B Involvement in Vitamin B₆ Biosynthesis

Abstract

Kinetic study of glycolaldehyde dehydrogenase was performed with isozymes of Escherichia coli B. The reaction equilibrium of isozyme A was estimated to lie in glycolate formation, while those of isozymes B and C were in glycolaldehyde formation. Isozyme A was released from cells with osmotic shock, while the others were not. Isozymes B and C were found in cytoplasmic fraction. Some reversal mutants derived from WG3 strain (one of vitamin B₆ auxotrophs) acquired ability to produce isozyme C. Based on these results, the non-involve-ment of isozyme A in vitamin B₆ biosynthesis was discussed.