Abstract
The interactions of the lysine-sensitive aspartokinase of E. coli K12 with lysine and leucine, as evidenced in the inhibition and binding curves, are well explained by the equations of an allosteric V model. Mathematical treatments of such a model lead to new linearized plots. These representations are applied to experimental results and allow the direct determination of some parameters of the model (equilibrium constant L'' and leucine Kd. The other parameters are obtained by an optimization method. The theoretical curves drawn according to this model account for the synergistic inhibition between lysine and leucine and for the role of the 2 nonequivalent lysine binding sites (autosynergy).