| Autor: |
Mcharfi, M., Aubry, A., Boussard, G., Marraud, M. |
| Zdroj: |
European Biophysics Journal; 1986, Vol. 14 Issue 1, p43-51, 9p |
| Abstrakt: |
IR, H-NMR and X-ray experiments have been carried out on dipeptides with the Pro-Asp and Pro-Asn sequences protected on both ends by amide groups. The Pro-Asp dipeptide was investigated for the carboxylic, methyl ester and carboxylate forms of the Asp residue. In solution, all dipeptides are found to accommodate almost exclusively the βI-turn conformation stabilized by an interaction between the Asp or Asn-NH and CO bonds. The βI-turn percentage roughly parallels the basicity of the Asp or Asn side substituent, and decreases from Asp to Asn, and to Asp or Asp (OMe). The βI-turn, stabilized by the interaction involving the Asp-CO site, is retained in the crystal structure of the Pro-Asp(OMe) dipeptide. The Pro-Asp and Pro-Asn dipeptides assume a βII-turn conformation in the solid state and the polar Asp or Asn side-groups are involved in a complex network of intermolecular interactions. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
| Externí odkaz: |
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