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
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(537 views) Di Natale G, Impellizzeri G, Pappalardo G
Keywords: Amyloidogenic Peptide Fragment, Fatal Familial Insomnia (ffi), Human Prion Proteins, Neurotoxic Effect, Conformations, Electrostatics, Hydrophobicity, Ionic Strength, Micelles, Nuclear Magnetic Resonance, Ph Effects, Article, Chemistry, Circular Dichroism, Methodology, Nuclear Magnetic Resonance Spectroscopy, Protein Conformation, Protein Secondary Structure, Sensitivity And Specificity, Protein Structure,
Affiliations: *** IBB - CNR ***
Dipartimento di Scienze Chimiche, Università di Catania, V.le A. Doria 6, 95125, Catania, Italy
Istituto di Biostrutture, Bioimmagini-Sezione di Catania, CNR, V.le A. Doria 6, 95125, Catania, Italy
References: Not available.
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
Two peptide fragments, corresponding to the amino acid residues 106-126 (PrP[Ac-106-126-NH2]) and 106-114 (PrP[Ac-106-114-NH2]) 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-NH2] and PrP[Ac-106-114-NH2] were investigated using CD and NMR spectroscopy. CD results showed that PrP[Ac-106-126-NH2] 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-NH2] fragment showed similar propensities when investigated under the same experimental conditions as those employed for PrP[Ac-106-126-NH2]. From CD experiments at different SDS concentrations, an alpha-helix/beta-sheet conformational transition was only observed in the blocked PrP[Ac-106-126-NH2] sequence. The NMR analysis confirmed the helical nature of PrP[Ac-106-126-NH2] in the presence of SDS micelles. The shorter PrP[Ac-106-114-NH2] 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-NH2].
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
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