Publication details
Hydroperoxidic inhibitor of horse liver alcohol-dehydrogenase activity, tightly bound to the enzyme-NAD+ complex, characteristically degrades the coenzyme
| Authors | |
|---|---|
| Year of publication | 1992 |
| Type | Article in Periodical |
| Magazine / Source | Journal of Enzyme Inhibition |
| MU Faculty or unit | |
| Citation | |
| Keywords | HORSE LIVHORSE LIVER ALCOHOL DEHYDROGENASE; P-METHYLBENZYL HYDROPEROXIDE;TIGHT-BINDING INHIBITIONER ALCOHOL DEHYDROGENASE; P-METHYLBENZYL HYDROPEROXIDE;TIGHT-BINDING INHIBITION |
| Description | The strong inhibition of horse liver alcohol dehydrogenase (HLAD) by p-methylbenzyl hydroperoxide (XyHP)7 is only transient, XyHP behaves also as a pseudo-substrate of the enzyme and in the presence of NAD+, is degraded by HLAD to (as yet unidentified) non-inhibiting products while the NAD+ is converted to a derivative similar to the "NADX", originally observed in an analogous reaction of HLAD with hydrogen peroxide.4 The apparent K(M) for XyHP is approximately 10(4) times smaller than that for H2O2. The catalytic constant k(cat) for HLAD degradation of XyHP is two orders of magnitude less than that for ethanol dehydrogenation. XyHP inhibits both directions of the alcohol-aldehyde interconversion with equal potency. The first step of the inhibition mechanism is a tight binding of XyHP to the binary HLAD-NAD+ complex. |