Novel stereoselective incorporation and hydrolysis of long-chain amino-acid substrates by vesicular membrane systems which include tri- or tetra-peptide catalysts

Abstract

In the vesicular membrane systems comprising N,N-didodecyl-N,N-dimethylammonium bromide and tri- or tetra-peptide catalysts (pH 7.68; ionic strength µ= 0.15; 298 K), Z-L-Leu-L-His-L-Leu (or Z-L-Leu-L-His-L-Leu-L-Leu), having a hydrophobic terminal L-leucine (or L-leucyl-L-leucine) unit, contributed to the stereoselective binding of long-chain p-nitrophenyl N-hexadecanoyl-L(and D)-phenyalanates with the remarkably high binding ratio Kb(L/D)= 11 (or 7.3) and overall stereoselectivity [kcat(L/D)= 35 (or 8.1)].