SYNTHESIS OF ENTEROSTATIN-AMIDE BY THE XAA-PROLYL DIPEPTIDYL AMINOPEPTIDASE FROM LACTOCOCCUS-LACTIS SUBSP LACTIS NCDO-763

The Xaa-prolyl dipeptidyl aminopeptidase from Lactococcus lactis. subsp. lactis N.C.D.O. 763 (PepX; 'X-PDAP'; EC 3.4.14.5) was used as a catalyst in the kinetically controlled synthesis of enterostatin-amide, APGPR-NH2 (the one-letter code for amino acids is used). Two successive reactions in aqueous media were performed to obtain this peptide from R-NH2, GP and AP p-nitroanilide. The reaction conditions were optimized by varing the pH and nucleophile concentration. The first reaction gave GPR-NH2, the amide of the fibrin anti-polymerant GPR with a 90% yield. The second reaction produced APGPR-NH2, with a 49.5% yield. The overall yield of both reactions was 45%. The reaction time was similar to 30 min for each step.