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Updated: Aug 4, 2026

Steady-state, Pre-steady-state, and Single-turnover Kinetic Measurement for DNA Glycosylase Activity
Published on: August 19, 2013
The kinetics of substrate-induced inactivation
1Laboratory of Molecular Biophysics, University of Oxford, U.K.
Abstract:
The kinetics of a branched-pathway mechanism for a simple enzymic reaction were studied. In this mechanism there is reversible formation of an inactive form of the second complex along the pathway. This substrate-induced inactivation typically results in the progress curve showing a burst. Three parameters can be obtained from the progress curve: the initial rate, the final rate and the rate constant characterizing the transient. The rate constant for the conversion of the inactive form of the complex into the active form can be obtained either from these parameters or by measuring the regain of enzymic activity. The partition ratio can also be obtained from the three parameters; this is the ratio of the rate of conversion of complex into product to the rate of conversion of complex into inactive form. Simulations give guidance to the conditions required for accurate determinations of the rate constants.
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