Biomimetic recognition and peptidase activities of transition state analogue imprinted chymotrypsin mimics

Abstract

The first peptidolysis reaction utilizing transition state analogue imprinted polymer was demonstrated utterly in the viewpoint of size and shape-selective substrate recognition. The enzyme mimic polymer was synthesized from the amino acid triad histidine, aspartic acid and serine in presence of phenyl-1-(N-benzyloxycarbonylamino)-2-(phenyl)ethyl phosphonate transition state analogue (TSA) by molecular imprinting technique. The polymer catalyst synthesized exhibited high selectivity and performed as a reliable tool for peptidolytic reactions. The peptidase activity of the enzyme mimic polymer catalyst was investigated by following the hydrolysis of dipeptides spectrophotometrically at 207nm and the kinetic parameters, rate acceleration kaccand imprinting efficiencykim, were evaluated. The imprinted peptidase displayed a rate acceleration of 1.67×103 contrasted with the uncatalyzed peptidolysis and an imprinting efficiency of 45 over the non-imprinted control polymer. The artificial peptidase amazingly promoted the hydrolysis of dipeptides having Phe/Tyr amino acid as the C-terminal residues discriminating chymotrypsin specific and non-specific substrates. The mimic exhibited higher rate acceleration and substrate specificity towards peptides compared to amino acid p-nitroanilides. Despite the fact that natural enzyme is much superior to the MIP catalyst in hydrolase activities, the mimic portrays high thermal stability, prolonged life span and unrivaled recyclability and reusability.