The glucose-induced switch between glycogen phosphorylase and glycogen synthase in the liver: outlines of a theoretical approach.

The glucose-induced switch between glycogen phosphorylase and glycogen synthase in the liver is investigated by means of a theoretical approach based on a minimal, bicyclic cascade model involving the reversible phosphorylation of the two enzymes. The aim of the analysis is to evaluate the contribution of different factors to the sequential changes in the activity of glycogen phosphorylase and glycogen synthase observed following the addition of suprathreshold amounts of glucose.