Concentration- and Structure-Dependent Effects of Amides on Protease Activity in Organic Solvents

Article abstract of DOI:10.1246/bcsj.67.1367

The catalytic activity of α-chymotrypsin (CT) in the transesterification of N-acetyl-L-tyrosine methyl ester to its ethyl ester in aqueous-organic media was markedly enhanced by replacing a part of water with foramide.The activity of CT was strongly dependent on the formamide/water ratio, and excess formamide retarded the activity.Addition of formamide to reaction mixtures at constant water contents exhibited similar activation-deactivation profiles for CT.A kinetic study revealed that the rate acceleration is due to an increase in k_cat rather than a change in K_m.At a given concentration of amides (0.5 M, M = mol dm^-3), propionamide and DMF were much less effective than formamide for activation of CT.The results suggest that foramide interacts with CT in a different way from water.