NR AUTR
AU Di Natale,G.; Impellizzeri,G.; Pappalardo,G.
TI Conformational properties of peptide fragments homologous to the 106-114 and 106-126 residues of the human prion protein: a CD and NMR spectroscopic study.
QU Organic and Biomolecular Chemistry 2005 Feb 7; 3(3): 490-7
PT journal article
AB Two peptide fragments, corresponding to the amino acid residues 106-126 (PrP[Ac-106-126-NH(2)]) and 106-114 (PrP[Ac-106-114-NH(2)]) of the human prion protein have been synthesised in the acetylated and amide form at their N- and C-termini, respectively. The conformational preferences of PrP[Ac-106-126-NH(2)] and PrP[Ac-106-114-NH(2)] were investigated using CD and NMR spectroscopy. CD results showed that PrP[Ac-106-126-NH(2)] mainly adopts an alpha-helical conformation in TFE-water mixture and in SDS micelles, while a predominantly random structure is observed in aqueous solution. The shorter PrP[Ac-106-114-NH(2)] fragment showed similar propensities when investigated under the same experimental conditions as those employed for PrP[Ac-106-126-NH(2)]. From CD experiments at different SDS concentrations, an alpha-helix/beta-sheet conformational transition was only observed in the blocked PrP[Ac-106-126-NH(2)] sequence. The NMR analysis confirmed the helical nature of PrP[Ac-106-126-NH(2)] in the presence of SDS micelles. The shorter PrP[Ac-106-114-NH(2)] manifested a similar behaviour. The results as a whole suggest that both hydrophobic effects and electrostatic interactions play a significant role in the formation and stabilisation of ordered secondary structures in PrP[Ac-106-126-NH(2)].
MH Circular Dichroism; Humans; Magnetic Resonance Spectroscopy/methods; Peptide Fragments/*chemistry; Prions/*chemistry; Protein Conformation; Protein Structure, Secondary; Research Support, Non-U.S. Gov't; Sensitivity and Specificity
AD Dipartmento di Scienze Chimiche, Universita di Catania, 95125 Catania.
SP englisch
PO England