Two theoretical problems concerning the irreversible modification kinetics of enzyme activity.

Some years ago, a systematic study on the kinetics of irreversible modification of enzyme activity was presented by Tsou (1988, Adv. Enzymol. Relat. Areas molec. Biol. 61, 381-436). This paper presents a discussion of the theoretical aspects of Tsou's method for the determination of the rate constants for the irreversible modification reaction. Range of validity for the kinetic equations of substrate reaction in the presence of the modifier is discussed quantitatively. The expressions of A, B, v* and [P]infinity for any enzyme catalyzed reaction mechanism are derived.