B. Anderson, M. L. Tanchoco, A. Pozzo
May 3, 1982
Citations
0
Influential Citations
9
Citations
Journal
Biochimica et Biophysica Acta
Abstract
Abstract Four α,β-unsaturated carbonyl derivatives, benzoylacrylates were studied for effectiveness and selectivity in enzyme inactivation. The enzymes chosen for study contained essential sulfhydryl groups, the properties of which varied with their immediate protein environment. Benzoylacrylic acid, methyl benzoylacrylate, toluoylacrylic acid and methyl toluoylacrylate were demonstrated selectively to inactivate yeast alcohol dehydrogenase (alcohol: NAD + oxidoreductase, EC 1.1.1.1) and yeast glutathione reductase (NAD(P)H: oxidizedglutathione oxidoreductase, EC 1.6.4.2) through the covalent modification of the essential sulfhydryl groups of these enzymes. In each case, ligands bound at the enzyme catalytic site protected the enzymes from inactivation. The methyl esters were considerably more effective than the free acids in these inactivation processes, observations attributed to nonpolar interactions with the enzymes since the large inactivation rate differences could not be accounted for by different reactivities in chemical reactions with cysteine. Yeast 6-phosphogluconic dehydrogenase (6-phospho- d -gluconate:NADP + 2-oxidoreductase (decarboxylating, EC 1.1.1.44) was relatively insensitive to inactivation by benzoylacrylates as expected from the more polar environment of the essential sulfhydryl groups of this enzyme.