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Accueil > Publications > Recherche par années > Années 1990 > 1999

Henin, O ; Barbier, B ; Boillot, F ; Brack, A

Zinc-induced conformational transitions of acidic peptides : Characterization by circular dichroism and electrospray mass spectrometry

Chemistry-A European Journal 5 (1) 218-226

par Administrateur - publié le

Abstract :

A series of amphiphilic peptides have been synthesized which have a defined chain length and are based either on the dipeptide periodicity Asp-Leu or the tetrapeptide periodicity Leu-Asp-Asp-Leu. Their behavior in the presence of low concentrations of metal ions was studied by circular dichroism spectroscopy, In pure water, the peptides adopt a random coil conformation. The addition of Zn2+ specifically induces a beta-sheet structure for (Asp-Leu)(n) and an alpha-helix structure for (Leu-Asp-Asp-Leu)(n)-Asp. The conformational transitions are dependent on the chain length : the critical main chain length for beta-sheets and alpha-helix formation is between 10 and 24 residues, and between 13 and 25 residues, respectively. The addition of NH4+ and Mg2+ have no effect, whereas Ca2+ has only a slight effect on the conformation.