A New Approach for Determination of the Selectively Favoured Kinetic Design of Enzyme Reactions

✍ Scribed by Gösta Pettersson

• Publisher: Elsevier Science
• Year: 1996
• Tongue: English
• Weight: 165 KB
• Volume: 183
• Category: Article
• ISSN: 0022-5193
• DOI: 10.1006/jtbi.1996.0211

✦ Synopsis

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 a 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.