Figure 3.
Kinetic model of a two-enzyme group-transfer pathway. Arrows indicate the direction of the flux; all elementary reactions are assumed to be reversible. The rate constants used for the simulation were as follows (ki denotes the rate constant in the forward direction relative to the arrowheads; k−i indicates the rate constant in the reverse direction): k1 = 1, k−1 = 0.5, k2 = 5, k−2 = 2, k3 = 500, k−3 = 250, k4 = 10, k−4 = 20, k5 = 1, k−5 = 0.5, k6 = 5, and k−6 = 1. A series of steady states was calculated in which the concentrations x0 and x2 were varied from 0.5 to 10 and the concentrations x1 and x3 were varied from 0.05 to 1 whereas the total concentrations e1 and e2 were increased from 0.1 to 2 concomitantly. Units are arbitrary.