Does any enzyme follow the Michaelis—Menten equation?

Abstract

A literature search has been conducted to see to what extent steady-state kinetics studies in the period 1965-1976 have revealed deviations from Michaelis-Menten kinetics. It was found that over 800 enzymes have been reported as giving complex curves for a variety of reasons and a group by group classification of all these enzymes has been carried out listing all the types of variations reported and the authors' explanations. In addition, for highly complex curves, we have determined the minimum degree of the rate equation. There were very few determined attempts to demonstrate adherence to the Michaelis-Menten equation over a wide variety of experimental conditions and substrate concentration and almost invariably detailed experimental work revealed unsuspected complexities. For these reasons, it is concluded that the assumption that most enzymes follow the Michaelis-Menten equation can not be supported by an appeal to the literature.

Interactions of Fungicides and Pesticides with Specific Enzymes

“…This occurs when the inhibitor binds at a site away from the substrate binding site, causing a reduction in the catalytic rate. It is quite rarely found as a special case of mixed inhibition (Henley & Sadana, 1985;Hill et al, 1977;Koshland, 1962). The fractional inhibition is identical at all substrate concentrations and cannot be overcome by increasing substrate concentration due to the reduction in Vmax.…”

Generalized definitions of inhibition patterns for non‐michaelian enzyme steady‐state kinetics

“…[6,7 ] ) cannot be described by the MichaelisMenten equation has called for a generalization of the nomenclature of i~b~tion patterns of reversible inhibitors. The problem has been whether the competitive, noncompetitive and uncompetitive (or anticompetitive) inhibition can be defined for cases in which rate equations contain second-or higher-degree terms in substrate concentration.…”

Microplate fluorescence protease assays test the inhibition of select North American snake venoms' activities with an anti-proteinase library

“…8. Non MichaeliseMenten reaction conditions or reactions are not a particularly unusual observation among enzymes as a whole (Hill et al, 1977). This data indicates that the reaction conditions are well below the Km, as might be expected given that casein is a nonspecific protease substrate and the venom in question contains a variety of distinct proteases.…”