Pyruvate dehydrogenase complex from higher plant mitochondria and proplastids

The pyruvate dehydrogenase complex from pea (Pisum sativum L.) mitochondria was purified 23-fold by high speed centrifugation and glycerol gradient fractionation. The complex had a s_20,w of 47.5S but this is a minimal value since the complex is unstable. The complex is specific for NAD⁺ and pyruvate; NADP⁺ and other keto acids give no reaction. Mg²⁺, thiamine pyrophosphate, and cysteine are also required for maximal activity. The pH optimum for the complex was between 6.5 and 7.5.