SYNTHESIS AND PROPERTIES OF HIGH-MOLECULAR-WEIGHT POLYPEPTIDES CONTAINING TRYPTOPHAN .3. SYNTHESIS AND PROPERTIES OF COPOLYPEPTIDES CONTAINING 1-N-IN-FORMYLTRYPTOPHAN WITH ALANINE

N-Carboxy-N-in-formyltryptophan anhydride 4-(L-1-N-in-formylindol-3-yl methyl)-2,5-oxazoldine dione, Trp(Form) NCA) was synthesized by formyl ation of the indole group of tryptophan, followed by N-carboxylation. The reactivity of copolymerization of Trp(Form) NCA with N-carboxy-L-a lanine anhydride (4-methyl-1-2,5-oxazolidinedione, L-Ala NCA) was high er than that of Trp NCA. The helix contents of the formed copolypeptid es, estimated by CD spectra, were remarkably decreased at a content of about 27% of Trp(Form). The content of Trp(Form) residue needed to de stroy helix conformation in the copolypeptides was more than that of T rp residue of 8%.