TGE FT-ICR


Partenaires

CNRS
Logo Ecole Polytechnique Logo ESPCI
Logo UPS Logo UDL
Logo UPMC Logo Universite de Lille 1
Logo Rouen Logo INSA Rouen Normandie



Accueil du site > Production scientifique > Binding motifs of silver in prion octarepeat model peptides : a joint ion mobility, IR and UV spectroscopies, and theoretical approach

Binding motifs of silver in prion octarepeat model peptides : a joint ion mobility, IR and UV spectroscopies, and theoretical approach

Date de publication: 1er juin 2012

B. Bellina, I. Compagnon, L. MacAleese, F. Chirot, J. Lemoine, P. Maître, M. Broyer, R. Antoine, A. Kulesza, R. Mitrić, V. Bonačić-Koutecký, P. Dugourd
Phys. Chem. Chem. Phys. 14 11433-11440 (2012). DOI

Travail réalisé sur le site de l’Université Paris-Sud.

Abstract

Transition metal-ion complexion is essential to the function and structural stability of many proteins. We studied silver complexation with the octarepeat motif ProHisGlyGlyGlyTrpGlyGln (Pro proline, His histidine, Gly glycine, Trp tryptophan, Gln glutamine) of the prion protein, which shows different sites for metal chelation including amide, indole and imidazole groups. This octapeptide and is known as a favourable transition metal binding site in Prion protein. We used ion mobility spectrometry, infrared multiple photon dissociation (IRMPD) spectroscopy and density functional theory calculations to describe the binding motifs of a silver cation on HisGlyGlyGlyTrp peptide as well as on peptide subsequences. Ultra-violet (UV) photodissociation and collision induced dissociation mass spectrometry was then exploited to study the influence of binding sites on optical properties and on the ground and excited states reactivity of the peptide. We show that the metal cation is bound to indole and imidazole groups through electrostatic interactions and that charge transfers from the indole group to the silver cation occur in excited electronic states.