Figure 4

Simulated results of glycogen cascade system in liver under starved conditions. (A) Fractional modification of enzymes at various concentrations of glucose. The sensitivity of the fractional dose-response curve of glycogen synthase (curve a, ~10.4), phosphorylase (curve b, ~6.2), phosphorylase kinase (curve c, ~1.6), CAPK (curve d, ~1.12) (B) Fractional modification of enzymes at various concentrations of cAMP. The sensitivity of the fractional dose-response curve of glycogen synthase (curve a, ~5.2), phosphorylase (curve b, ~3.1), phosphorylase kinase (curve c, ~1.6), CAPK (curve d, ~1.12) (C) Fractional modification of enzymes at various concentrations of glucose-6-phosphate. The sensitivity of the fractional dose-response curve of glycogen synthase (curve a, ~10.5) and phosphorylase (curve b, ~6.4). (D) Fractional modification of phosphorylase as function of glycogen synthase. The dissociation constant (Kd) of phosphorylase-a binding to glycogen synthase phosphatase is taken as 2 μ M (~1000 fold higher Kd than used to simulate results shown in Fig 3). Appreciable amounts of both glycogen synthase and phosphorylase exist in such a fasted state.