Effects of modifiers on the kinetics of two-substrate enzyme reactions

Steady state rate equations have been derived for ordered bi bi and ping pong bi bi reactions in which there are (a) one or two nonsubstrate modifiers, (b) two different binding sites for a single nonsubstrate modifier, (c) one or two substrates acting as modifiers, and (d) both nonsubstrate modifiers and substrates acting as modifiers. The deviation of these equations from the Michaelis–Menten equation is shown and methods are suggested by which many of these mechanisms can be distinguished experimentally.