[Effect of SH-reagents and thiol compounds on aminopeptidase from Aspergillus oryzae]

It is shown that iodacetate and iodacetamide produce an insignificant inhibition of the Asp. oryzae aminopeptidase activity, para-chloromercuribenzoate is a stronger inhibitor. Dithiotreitol, beta-mercaptoethanol, reduced glutathione also cause a considerable loss in the enzyme activity. The inhibitory effect is intensified with a combined action of para-chloromercuribenzoate and EDTA. The studies of para-chloromercuribenzoate, iodacetate and iodacetamide effect on the activation of aminopeptidase apoenzyme by cobalt ions showed that the enzyme activity recovery is insignificant. It may be supposed that the enzyme thiol groups are bound with the metal ions necessary for the catalytic activity.