Main enzyme for glycogen metabolism

The key enzyme for glycogenolysis is phosphorylase, which is activated by glucagon and adrenaline, under the stimulus of hypoglycemia. ii. The key enzyme for glycogen synthesis is glycogen synthase, the activity of which is decreased by adrenaline but is enhanced by insulin, under the stimulus of hyperglycemia (Fig. 9.40). Glycogen metabolism is regulated by coordinated regulation of glycogen synthase and glycogen phosphorylase. The regulatory mechanisms include allosteric control as well as hormonal control by covalent modification of enzymes. The allosteric effectors are ATP, Glucose-6-phosphate, and AMP.Ref: DM Vasudevan, 7th edition