skip to main content

Effect of a hydrophobic amino acid at position (i −1) on the stability of β-turns in hydrophilic pentapeptides as studied by NMR and molecular mechanics

Liu, Xiaohong ; Fraga, Serafin ; Otter, Albin ; Kotovych, George ; Scott, Paul G

Canadian journal of chemistry, 1995-07-01, Vol.73 (7), p.972-980 [Periódico revisado por pares]

Ottawa, Canada: NRC Research Press

Texto completo disponível

Citações Citado por
  • Título:
    Effect of a hydrophobic amino acid at position (i −1) on the stability of β-turns in hydrophilic pentapeptides as studied by NMR and molecular mechanics
  • Autor: Liu, Xiaohong ; Fraga, Serafin ; Otter, Albin ; Kotovych, George ; Scott, Paul G
  • É parte de: Canadian journal of chemistry, 1995-07-01, Vol.73 (7), p.972-980
  • Descrição: A detailed NMR study of the peptide NAc-FDEKA-NH 2 in aqueous and in CD 3 OH/H 2 O solutions as well as the N-acetylpentapeptide amides YDEKA, VDEKA, GDEKA, and the protected tetrapeptide NAc-DEKA-NH 2 in methanolic solutions indicates the importance of the first amino acid (at i −1) on stabilizing the type I β-turn. The data illustrate the hydrophobic stabilization of this turn, which is present in FDEKA, YDEKA, and VDEKA. For GDEKA and DEKA, the NMR data indicate that this turn is not present. Molecular mechanics calculations support this conclusion and indicate that for FDEKA and GDEKA the type I β-turn is distorted in both the vacuum and the solvated structures. For the solvated structures, the C α (i) − C α (i + 3) distance is 4.87 Å for FDEKA and 6.00 Å for GDEKA, which are to be compared with the value of 4.64 Å for an ideal type I β-turn, i.e., the distortion is far greater in GDEKA than in FDEKA. The calculations can be interpreted to indicate the presence of two major conformations in solution. Keywords: β-turns, FDEKA, pentapeptide.
  • Editor: Ottawa, Canada: NRC Research Press
  • Idioma: Inglês

Buscando em bases de dados remotas. Favor aguardar.