Abstract
The effect of donors (alcohol) on the kinetics of the enzyme-substrate complex (ES) of catalase and H2O2 has been investigated theoretically. It has been shown that low concentrations of the donor affect only the terminal stage of the kinetics by causing the otherwise stable complex to disappear. By increasing the concentration of the donor, at constant initial enzyme and substrate concentrations, the maximal concentration of the complex is also affected (decreased). The bimolecular rate constant of the reaction of ES with alcohol has been calculated by constructing simulated decay curves with the help of a computer and by comparing them with the experiment: k5 = (1.00 ± 0.05) × 103 M-1 sec-1. The "spontaneous" decomposition of ES is discussed and it is shown that it may be due either to the reduction of ES by a residual donor in the system (exogenous or endogenous) or to an irreversible transformation of ES into ES′ (inactive). Some evidence favoring the latter possibility is discussed.
Original language | English |
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Pages (from-to) | 951-955 |
Number of pages | 5 |
Journal | Journal of Physical Chemistry |
Volume | 79 |
Issue number | 10 |
DOIs | |
State | Published - 1975 |