CONTINUOUS ENZYMATIC PRODUCTION OF OLIGOPEPTIDES - SYNTHESIS OF AN ENKEPHALIN PENTAPEPTIDE IN A MULTISTAGE BIOREACTOR

A feasibility study of the continuous enzymatic production of short ol igopeptides was undertaken using the synthesis of [Leu5]-enkephalin pe ntapeptides as a model system. A three-stage bioreactor was designed t o perform the independent syntheses of the constituent tri- and dipept ide fragments and their subsequent condensation. Both the N-terminal ( N-X-L-Tyr.Gly.GlyOEt) and C-terminal (L-Phe.LeuNH2) peptides were prep ared in 75-85% yield in column reactors packed with Celite-immobilized alpha-chymotrypsin. The enkephalin pentapeptide was obtained in up to 30% yield in the third bioreactor module containing Celite-immobilize d proteinase K. The bioreactor was run continuously for over 1,000 h, producing, under steady-state conditions, up to 0.7 g day-1 of the pen tapeptide.