Enantioselective and Diastereoselective Cleavage of Amino Acid Esters in Coaggregates of Controlled Size

摘要

Stereoselective cleavages of N-protected amino acid and peptide p-nitrophenyl esters in various surfactant aggregate systems have been used as models to probe the origins of stereoselectivity in the proteolytic enzymes. Studies of enantioselectivity have emphasized the roles of hydrophobic interaction between catalyst and substrate, the structure of the aggregates, the effect of temperature, and the amino acid sequence of the peptide catalyst. Studies of diastereoselectivity in the functional micellar cleavages of di- and tripeptide substrates have generated molecular level models for substrate-surfactant interaction and pointed to the importance of chirality-specific supramolecular micellar effects. The enantioselectivity of cleavage of N-dodecanoyl-D(L)-phenylalaniates with LLL-Z-PheHisLeu, and the diastereoselectivity of cleavage of Z-D(L)-Pro-L-Pro-PNP by a functional iodosobenzoate surfactant, were well correlated by the apparent hydrodynamic diametes of coaggregates composed of double and single chain surfactants.