Carbon assimilation by Pseudomonas oxalaticus (OX 1). 6. Reactions of oxalyl-coenzyme A

Abstract

Oxalyl-CoA prepared by ester interchange between thiocresyl-hydrogen-oxalate and CoA is the product of CoA- and NADP-linked oxidation of glyoxylate in the presence of oxalyl-coenzyme-A reductase. The equilibrium constant for the reduction is 1.38 X 105 at 25[degree]. There is a nonenzymic ester interchange between oxalyl-CoA and thiol compounds such as cysteine and glutathione. This accounts for the previous inability to isolate oxalyl-CoA. The use of oxalyl-coenzyme-A reductase for the direct spectrophotometric determination of glyoxylate, oxalyl-CoA and CoA is discussed.