Conformational stabilization of enzymes in covalent catalysis

The enzymes aspartate aminotransferase, rhodanese, and chymotrypsin form covalent substituted-enzyme intermediates during the course of their catalysis. The present analyses show that, in these covalent intermediates, the enzyme proteins are stabilized against pH-induced structural transitions to inert forms that occur in the free enzyme species and other forms not covalently substituted.