title: Conformational characteristics of homo-oligopeptides of O-benzyl-L-tyrosine.
abstract: Conformational studies of X[-L-Tyr(Bzl)-]n-series bound to polyethyleneglycol (X = H2, Nps; n = 3-8) in the solid state and in solvents of different polarities and capabilities of forming hydrogen bonds are reported. By using i.r. absorption, the occurrence of the beta-structure in the higher oligomers in the solid state was established. By means of i.r. absorption and CD the onset of that ordered conformation in solution was assessed as a function of chain length. The effects induced by the presence of the N-protecting group and added base, and by changing the nature of solvent on the conformational preferences of the [-L-Tyr(Bzl)-]n homo-peptides were also examined. The 2-nitrophenylsulphenyl chromophoric derivative of the alpha-amino group is proposed as a circular dichroism sensor for beta-structure in peptides.
mesh_terms: D055598:Chemical Phenomena; D002621:Chemistry; D002942:Circular Dichroism; D009842:Oligopeptides / Q000138:chemical synthesis*; D011487:Protein Conformation; D012996:Solutions; D013055:Spectrophotometry, Infrared; D014443:Tyrosine / Q000031:analogs & derivatives*
chemical_list: D009842:Oligopeptides; D012996:Solutions; D014443:Tyrosine