Enzymic Cleavage of Malate to Glyoxylate and Acetyl-Coenzyme A

抄録

It was demonstrated that malate is cleaved to acetyl-CoA and glyoxylate by an en-zyme preparation from Rhodopseudornonas sphe-roides when incubated in the presence of ATP, CoA and Mg⁺⁺. Available data suggest that the reaction is consisted of two enzymic reac-tions catalyzed by independent enzymes: the first enzyme catalyzing the formation of malyl-CoA from malate, ATP and CoA and the second enzyme catalyzing the cleavage of malyl-CoA to acetyl-CoA and glyoxylate. Both reactions appeared to be reversible al-though the over-all reaction seemed to be much in favour of the malyl-CoA cleavage. Neither succinyl-CoA synthetase nor CoA transfer from succinyl-CoA to malate appear-ed to be responsible to the formation of malyl-CoA. The significance of this enzymic reaction in relation to the porphyrin biosyn-thesis in R. spheroides was discussed.