C. Uchida, Y. Iizuka, E. Ohta
Mar 1, 1996
Citations
0
Influential Citations
6
Citations
Journal
Bulletin of the Chemical Society of Japan
Abstract
High-purity N-carboxyl L-tryptophan anhydride (L-4-indoylmethyl-2,5-oxazolidinedione) was synthesized in good yield. Copolypeptides with a random sequence of L-trypophan (Trp) with glycine (Gly), L-alanine (Ala), L-α-amino-n-butyric acid (Abu), L-n-valine (Nval), L-n-leucine (Nleu), L-leucine (Leu), L-γ-methylglutamate (Glu(OMe)), and L-methionine (Met) were synthesized by the copolymerization of the corresponding N-carboxy-α-amino acid anhydrides (NCA) in solution. The rate of polymerization of Trp NCA was less than that of the other amino acid NCAs. The helix contents of the formed copolypeptides, estimated by the circular dichroism (CD) spectra, were remarkably decreased at a content of about 8% of Trp involved in poly(Trp-co-Nval) (poly(Trp,Nval)), poly(Trp-co-Leu) (poly(Trp,Leu)), poly(Trp-co-Nleu) (poly(Trp,Nleu)), and poly(Trp-co-Glu(OMe)) (poly(Trp,Glu(OMe))), but was not decreased at that percentage in poly(Trp-co-Met) (poly(Trp,Met)).