ABSTRACT
In Chapter 5, initial velocity patterns obtained in the absence of added inhibitors were discussed for the most commonly encountered kinetic mechanisms. Evident is the fact that, in most cases, kinetic mechanism cannot be assigned solely on the basis of initial velocity patterns in the absence of added inhibitors. This inability to assign kinetic mechanism is partially a result of the degenerative nature of the initial velocity rate equation for a number of mechanisms, for example, rapid equilibrium random, steady-state ordered, and Theorell–Chance mechanisms. There are instances when an apparently diagnostic initial velocity pattern is obtained, as in the case of a rapid equilibrium ordered kinetic mechanism where intersection is on the ordinate when B is the varied reactant and A is the fixed varied reactant. However, even in these cases the interpretation remains ambiguous. In the example utilized, strong synergism in a rapid equilibrium random mechanism can also yield an initial velocity pattern that intersects on the ordinate. Other experimental approaches are required to further distinguish between the possible kinetic mechanisms. One such additional approach, which still makes use of initial velocity studies, is the use of inhibitors. In this chapter, inhibition studies will be considered in detail, first in general with respect 122to the kinds of inhibition and then specifically with respect to the kinds of inhibition patterns (double reciprocal plots) expected for a given kinetic mechanism for product and dead-end inhibition. Finally, other kinds of inhibition experiments, such as alternate substrate and product inhibition, will be discussed.
