A 15-mer model peptide was synthesised by the solid phase method. The solution structure of this peptide was investigated by circular dichroism (CD) and NMR spectroscopy. CD results indicated that the peptide adopts a helical conformation in the presence of 2,2,2-trifluoroethanol (TFE) and its helicity is influenced by pH. NMR studies, carried out in H2O/TFE (1:1), allowed the sequence-specific assignment of the proton resonances to be made, in addition to a more precise location of the helical structure in the peptide sequence. The ability of different divalent metal ions (Cu2+, Ni2+) to induce an alpha-helix was also investigated in aqueous solution by means of CD spectroscopy; the results obtained indicate that Ni2+ is able to promote the a-helical conformation at neutral pH. In contrast, the CD spectrum of the Cu2+-peptide complex does not show any indication of a helical conformation. The reasons for this behaviour are proposed on the basis of ESR and UV/Vis data.
|Titolo:||Synthesis, spectroscopic characterisation, and metal ion interaction of a new alpha-helical peptide|
|Autori interni:||PURRELLO, Roberto|
|Data di pubblicazione:||1998|
|Rivista:||CHEMISTRY-A EUROPEAN JOURNAL|
|Appare nelle tipologie:||1.1 Articolo in rivista|