Chymotrypsin-catalyzed peptide synthesis in an acetonitrile-water-system: studies on the efficiency of nucleophiles.

Peptide synthesis with chymotrypsin in organic solvents was investigated and the apparent partition constants have been measured. We find that the Papp values of the most amino acids and peptide derivatives are drastically changed and the stereo- and regiospecificity in acetonitrile/water mixture is reduced.