Synthesis and Properties of High-Molecular-Weight Polypeptides Containing Tryptophan II. Copolypeptides of Tryptophan with Various Amino Acids

Autor: Kaori Wakamatsu, Chieko Uchida, Masanao Oya, Eido Ohta, Yasuko Iizuka
Rok vydání: 1996
Předmět:
Zdroj: Bulletin of the Chemical Society of Japan. 69:791-796
ISSN: 1348-0634
0009-2673
DOI: 10.1246/bcsj.69.791
Popis: 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)).
Databáze: OpenAIRE