Peptide enzymatic microsynthesis, using carboxypeptidase Y as the catalyst: application to stepwise synthesis of Leuenkephalin.

In order to develop the use of carboxypeptidase Y (CPD-Y, EC 3.4.12.1) as a catalyst for radioactive hormonal synthesis, the stepwise synthesis of a pentapeptide, Leu-enkephalin, was studied on a microscale. Each peptide bond was formed by enzymatic catalysis, using microquantities of the precursors (amino acid or peptide esters as acyl-components and amino acid ester or amide as nucleophiles). The high condensation yields obtained suggests that CPD-Y can be a useful tool for preparation of radioactive hormonal peptides.