The temperature optima of enzymes: a new perspective on an old phenomenon

Careful analysis of the dependence of enzyme activity on assay temperature has revealed that some enzymes might have real temperature optima in which the decrease in catalytic rate at temperatures above the optimum is not pri marily a result of irreversible thermal inactivation. The 'equilibrium mode l' has been formulated to describe genuine temperature optima, and to sugge st a simple experimental method by which to distinguish these cases from th ose in which enzyme instability is the major determinant of temperature opt ima.