The hepatic adenylate cyclase system. III. A mathematical model for the steady state kinetics of catalysis and nucleotide regulation

A steady state kinetic model for hepatic adenylate cyclase is presented. The activity of the enzyme was assayed in the presence of a range of concentrations of magnesium, adenylylimidodiphosphate, 5' guanylylimidodiphosphate, and in the presence and absence of saturating concentrations of glucagon. The data were tested against proposed models using an iterative least squares curve fitting program and confidence estimates for the model parameters were obtained.