ABSTRACT
The pH dependence of an enzyme-catalyzed reaction has become a popular approach to identifying substrate or activator moieties and enzymic active-site ionizable residues which play a role in substrate binding and in catalysis. Some of the most useful pieces of information to be derived from studies on the effect of temperature are the thermodynamic parameters which may be estimated from the intrinsic dissociation or ionization constants, i.e., from those values derived kinetically and estimated at two or more temperatures. Sometimes useful information on the nature of the structure of the enzyme, in solution, may be gleaned from a study of the kinetics of inactivation under defined conditions of pH and temperature. A similar observation was made by Scopes in the case of the porcine-muscle enzyme. The temperatures at the intersection of the two fitted linear segments are indicated for both the brain type and muscle type.
