Enzyme Kinetics Far From the Standard Quasi-Steady-State and Equilibrium Approximations

Analytic approximations of the time-evolution of the single enzyme-substrate reaction are valid for all but a small region of parameter spsce in the positive initial enzyme-initial substrate concentration plane. We find velocity equations for the substrate decomposition and product formation with the aid of the total quasi-steady-state approximation and an aggregation technique for cases where neither the more normally employed standard nor reverse quasi-steady-state approximations are valid. Applications to determining reaction kinetic parameters are discussed. @ 2001 Elsevier Science Ltd. All rights reserved. Keywords-Total quasi-steady-state approximation, Fitting procedure, Aggregation technique, Singular perturbation.