Kinetics

Abstract

Kinetic studies give quantitative information about the behaviour of enzymes relevant to the mechanisms of individual enzyme reactions and to their metabolic functions and problems of metabolic control. Speakers in all sections of this symposium will no doubt be concerned with kinetic data of one kind or another. The rates of overall reactions in the steady state are the easiest data to obtain and perhaps the most directly useful at present in metabolism; they are also the data that must be ultimately explained by a satisfactory mechanism, although they are often difficult to interpret and alone can only give limited information about mechanisms. Nevertheless, classical studies of this kind have contributed substantially to the formation of most of the important concepts in enzymology, from the enzyme-substrate complex theory (1,2) itself to the induced fit theory (3) and allosteric phenomena (4) including the recent discovery of negative homotropic interactions (5,6). Whilst “the mere accumulation of rate data is an abhorrent phenomenon” (7), sufficiently detailed and precise catalytic data of the right kind can give valuable information about mechanism, and provides an essential framework for the design and interpretation of other investigations such as kinetic studies of individual steps by rapid reaction techniques, equilibrium studies of the binding of individual substrates to enzymes and isotope exchange experiments.