Exponential model for a two-ligand, regulatory enzyme. Part 1: computer programs for the determination of the model constants from initial velocity data.

The exponential model for a regulatory enzyme with two ligands (either two substrates or one substrate and an effector) provides an expression for the initial velocity of the catalysed reaction in terms of the fractional saturation of the enzyme by each ligand. This paper describes a program which determines the constants of the model from velocity data, measured with respect to the concentrations of the two ligands, when the corresponding fractional saturations are unknown. Listings of the essential routines, written in BASIC, are provided.