EFFECTS OF NORMAL AND THEIR BRANCHED ALCOHOLS WITH STRUCTURALLY VARIATION VARIATION ON KINETIC-PARAMETERS IN THERMOLYSIN-CATALYZED PEPTIDE HYDROLYSIS AND SYNTHESIS OF N-(BENZYLOXYCARBONYL)-L-PHENYLALANYL-L-PHENYLALANINE AND ITS METHYL-ESTER

When higher alcoholic solvents were added to the reaction medium, and the enhancement of the enzyme activity, followed by its reduction then inactivation, were observed in thermolysin-catalyzed peptide hgdrolysis and synthesis. The organic solvent content used was less than the saturating concentration in the buffer (i.e., water-organic one-phase system), The kinetic parameters, K-m and k(cat), at the alcoholic concentration giving maximal enzyme activity in these reactions changed linearly with increasing log P values of the alcohols and consequently k(cat)/K-m as well, When the branched isomers of alcohols with structurally minimal variation of which log P was equivalent theoretically,,were used as annexments, the kinetic parameters were also changed, The results, especially the changes of K-m for each organic solvent, suggested that each alcohol should act at the active site of the enzyme in its own effective mode.