Peptide synthesis in dimethylformamide-based organic media catalysed by non-covalent chymotrypsin-polyelectrolyte complexes

Chymotrypsin-catalysed kinetically-controlled peptide synthesis was studied in mixtures of dimethylformamide (DMF) and acetonitrile containing 6% wate r. The free enzyme showed no detectable activity with 60% or more DMF. Howe ver, by pre-forming a complex with polyacrylate (optimum 50 carboxyl groups to 1 enzyme molecule), activity and stability were good at 60% DMF, and re asonable at 70% DMF. In 60% DMF. the peptide Ac-Tyr-Lys-NH? could be made i n 95% yield using this catalyst.