GLYCOGEN-BOUND ENZYMES - A NEW METHOD OF ISOLATION

The plant protein concanavalin A is utilized as a tool in the isolation of glycogen-bound enzymes from an 8000g supernatant fraction of mouse-liver homogenate. The protein binds to glycogen to form a complex that can be separated by a short centrifugation at low speed. The precipitate can then be used without further treatment and is shown to contain glycogen synthetase, phosphorylase, and branching enzyme activities. A 25-fold increase in the yield of glycogen synthetase is obtained by using this method, as compared to isolation of the particulate glycogen-bound enzyme by highspeed centrifugation. The fact that enzyme activity can be assayed only 30 min after extraction of tissue represents an additional advantage of this new method. It is likely that the method can be used with other tissues and other branched polysaccharide-bound enzymes. © 1969.