Primary structure around the lipoate-attachment site on the E2 component of bovine heart pyruvate dehydrogenase complex

Abstract

Bovine heart pyruvate dehydrogenase complex was acetylated by using [3-14C]pyruvate in the presence of N-ethylmaleimide, with approx. 1 mol of acetyl groups being incorporated per mol of E2 polypeptide. After peptic digestion, lipoate-containing peptides were purified by high-voltage electrophoresis and ion-exchange and reverse-phase h.p.l.c. The amino acid sequence around the lipoic acid-attachment site of E2 was determined by automated Edman degradation. Acetylation of a lipoate cofactor bound to a lysine residue was verified by fast-atom-bombardment m.s.