[Formation of the glycogen synthase I-glycogen complex].

A glycogen-free glycogen synthase I was isolated from rabbit skeletal muscles as a tetramer. Using the light scattering technique, the formation of the glycogen synthase I--glycogen complex was investigated; the Kd value [(0.40 +/- 0.09) X 10(-7) M], the absorption capacity of glycogen towards the enzyme [aM = (1.89 +/- 0.4) X 10(-6) mol] and the number of enzyme-binding sites per polysaccharide molecule (n = 10) were determined, using rabbit liver glycogen (Mr = 5.28 X 10(6)). After the formation of the glycogen synthase I--glycogen complex has been completed, the reactivity of some SH-groups of the enzyme is reduced and some of them become masked towards 5,5'-dithiobis-2-nitrobenzoate.