Amino acid composition of α- and β-chains of yeast and wheat germ pyruvate decarboxylase

AbstractPyruvate decarboxylase, electrophoretically isolated from brewer's yeast and wheat germ, was resolved into α- and β-chains by SDS electrophoresis on polyacrylamide gel gradients. The chains were analysed for amino acid compostion by routine methods. Tryptophan was assayed without chain separation using the 280288 nm absorbance in 6 M guanidine-HCl. Considerable differences found between α- and β-chains rule out the hypothesis that β-chains originate from α-chains by proteolytic removal of a short piece of chain.Thus, the recently isolated structural gene for yeast PDC cannot suffice for coding both chains