Multiple forms of rat liver glycogen synthetase [formula omitted

Abstract

A procedure is reported for the acquisition of highly purified rat liver glycogen synthetase b . In density gradient centrifugation experiments 2 major peaks of synthetase b activity were found in the absence of ligands, plus small amounts of higher molecular weight components. The heavier peak appeared to be a dimer of the lighter peak and was of approximately 258, 000 to 284, 000 molecular weight. In the presence of ligands a single, nearly symmetrical peak of activity was obtained corresponding to the heavier of the 2 peaks. Similar observations were made with disc gel electrophoresis experiments where the presence of G-6-P converted the major component to a species of lower mobility. Preincubation of certain preparations of synthetase b with G-6-P also produced a marked time-dependent increase in activity.