MOLECULAR DESIGN OF POLYPEPTIDE AS FUNCTIONAL POLYMER - NEW SYNTHESIS OF POLYPEPTIDES CONTAINING CYSTEINE RESIDUES

For SH protection of cysteine, the ethylcarbamoyl (Ec) group which is labile in mild alkaline conditions was employed. Amino acids homopolymer and copolymers were synthesized from N-carboxy anhydrides (NCA) of Cys(S-Ec) and other amino acids. The NCA of Cys(S-Ec) self- and co-polymerized in a similar way as NCAs of other amino acids. The ethylcarbamoyl group could be easily and quantitatively cleaved from the polymers by the mild treatment with sodium methoxide in methanol.