The effect of phosphorylation on oxidative and CoA- and NAD+-independent turnover of pyruvate by pyruvate dehydrogenase complex in the brain

It was shown that in the presence of ATP and Mg2+ the phosphorylation of the partially purified pyruvate dehydrogenase complex and the enzyme in isolated brain mitochondria inhibited the oxidative activity of the pyruvate dehydrogenase complex. The phosphorylation did no affect essentially the nonoxidative decarboxylation of pyruvate to form CO2 and acetaldehyde. In native mitochondria from the bovine brain the nonoxidative activity of the pyruvate dehydrogenase complex reached about 10% as compared to the oxidative activity of enzyme.