Purification of bovine kidney and heart pyruvate dehydrogenase phosphatase on Sepharose derivatized with the pyruvate dehydrogenase complex.

Pyruvate dehydrogenase phosphatase has been purified to apparent homogeneity from mitochondrial extracts of both beef heart and beef kidney. An essential step in this three-step purification is affinity chromatography of a largely purified phosphatase fraction using Sepharose beads to which pyruvate dehydrogenase complex is covalently bound through the lipoic acid residues of the dihydrolipoyl transacetylase component of the complex. The purified phosphatase, which has a native relative molecular mass, Mr, of about 140000, is composed of two nonidentical subunits of Mr 89000 and 49000.