Purification of bovine heart glycogen synthase

Abstract

Glycogen synthase was purified to apparent homogeneity from bovine heart muscle by a procedure involving precipitation of the enzyme in the presence of added glycogen by polyethylene glycol, chromatography on DEAE-Sephacel, and high-speed centrifugation through a sucrose-containing buffer. The enzyme was maintained in the presence of glycogen during the isolation procedure. Glycogen synthase I and D preparations were obtained having specific activities of 21–25 and 30–35 units/mg protein at pH 7.8 and 30°C and having activity ratios of 0.5–0.6 and 0.05–0.10, respectively, when assayed in the absence and in the presence of glucose 6-P.