A new approach for determination of the selectively favoured kinetic design of enzyme reactions.
A new criterion is applied for characterization of the kinetic design of enzymes that should be favoured by a selective pressure in the direction of increased metabolic reaction flux. According to this criterion, the selectively favoured state of a metabolic sequence of enzyme reactions conforming to Michaelis-Menten kinetics is identical with the uniform one which is known to optimize reaction flux for a given average magnitude of enzyme concentrations and of true and apparent first-order rate constants in the reaction system. It is argued that presently observed values of on-velocity constants for metabolite binding to enzymes are unlikely to represent the upper limit for diffusion-controlled association process and are more likely to represent those corresponding to the selectively favoured kinetic design at the present stage of the evolutionary development of enzyme function.
Pettersson
G
G
Avdelningen För Biokemi, Kemicentrum, Lunds Universitet, Sweden.
D000818:Animals; D004789:Enzyme Activation; D004798:Enzymes / Q000378:metabolism*; D007700:Kinetics; D008954:Models, Biological; D012641:Selection, Genetic
D004798:Enzymes