Pig heart [35S]thiophosphoryl pyruvate dehydrogenase complexes

Thiophosphorylation of the pig heart pyruvate dehydrogenase complex with ATP [35S] (adenosine 5'[gamma-thio]-triphosphate) was analogous to phosphorylation with [gamma-32P]ATP except that thiophosphorylation of sites 2 and 3 was more rapid. With pyruvate dehydrogenase phosphatase the rate of dethiophosphorylation was 0.5% of that of dephosphorylation. Thiophosphorylation of sites 2 and 3 in complex phosphorylated in site 1 reduced the rate of dephosphorylation of site 1.