ENZYMATIC PEPTIDE-SYNTHESIS IN FROZEN AQUEOUS SYSTEMS - USE OF N-ALPHA-UNPROTECTED UNUSUAL ACYL DONORS

alpha-Chymotrypsin (EC 3.4.21.1) was used for catalyzing the reaction of various N alpha-unprotected non-coded phenylalanine ester derivativ es with H-Leu-NH2 and H-Arg-NH2 in frozen aqueous solution at -15 degr ees C. Compared with reactions at room temperature, a significant yiel d increasing effect could be established. The kinetic parameters of es ter hydrolysis show that most of the unusual acyl donors (compared wit h the coded phenylalanine methyl ester) are well accepted substrates f or alpha-chymotrypsin.