Apparent co-operative effect of acetyl-CoA on pigeon kidney pyruvate carboxylase

Abstract

All pyruvate carboxylases purified thus far from mammalian and avian species have been found to be inactive in the absence of an acyl-CoA. In contrast, the pyruvate carboxylase purified from Pseudomonas citronellolis and Aspergillus niger show maximal activity in the absence of an acyl-CoA. In yeast, this enzyme is active in the absence of acetyl-CoA but either CoA or its acetyl derivative is capable of inducing a 2-fold stimulation of enzymic activity [ 11. The reaction catalysed by pyruvate carboxylase from pigeon kidney apparently requires “acetyl coenzyme A” as an added cofactor: