title: Water response to ganglioside GM1 surface remodelling.
abstract: Gangliosides are biological glycolipids participating in rafts, structural and functional domains of cell membranes. Their headgroups are able to assume different conformations when packed on the surface of an aggregate, more lying or standing. Switching between different conformations is possible, and is a collective event. Switching can be induced, in model systems, by concentration or temperature increase, then possibly involving ganglioside-water interaction. In the present paper, the effect of GM1 ganglioside headgroup conformation on the water structuring and interactions is addressed.
  
  
  
  Depolarized Rayleigh Scattering, Raman Scattering, Quasielastic Neutron Scattering and NMR measurements were performed on GM1 ganglioside solutions, focusing on solvent properties.
  
  
  
  All used techniques agree in evidencing differences in the structure and dynamics of solvent water on different time-and-length scales in the presence of either GM1 headgroup conformations.
  
  
  
  In general, all results indicate that both the structural properties of solvent water and its interactions with the sugar headgroups of GM1 respond to surface remodelling. The extent of this modification is much higher than expected and, interestingly, ganglioside headgroups seem to turn from cosmotropes to chaotropes upon collective rearrangement from the standing- to the lying-conformation.
  
  
  
  In a biological perspective, water structure modulation could be one of the physico-chemical elements contributing to the raft strategy, both for rafts formation and persistence and for their functional aspects. In particular, the interaction with approaching bodies could be favoured or inhibited or triggered by complex-sugar-sequence conformational switch. This article is part of a Special Issue entitled "Science for Life" Guest Editor: Dr. Austen Angell, Dr. Salvatore Magazù and Dr. Federica Migliardo.
authors.affiliation: Dept. of Medical Biotechnologies and Traslational Medicine, University of Milano, LITA, Via Fratelli Cervi, 93, 20090 Segrate, Italy.
authors.forename: P
authors.initials: P
authors.lastname: Brocca
authors.affiliation: Dept. of Medical Biotechnologies and Traslational Medicine, University of Milano, LITA, Via Fratelli Cervi, 93, 20090 Segrate, Italy.
authors.forename: V
authors.initials: V
authors.lastname: Rondelli
authors.affiliation: Dept. of Physics and Earth Sciences, University of Messina, Viale F. Stagno D'Alcontres, 31, 98166 Messina, Italy.
authors.forename: F
authors.initials: F
authors.lastname: Mallamace
authors.affiliation: Dept. of Physics and Earth Sciences, University of Parma, Parco Area delle Scienze, 7/A, 43124 Parma, Italy.
authors.forename: M T
authors.initials: MT
authors.lastname: Di Bari
authors.affiliation: Dept. of Physics and Earth Sciences, University of Parma, Parco Area delle Scienze, 7/A, 43124 Parma, Italy.
authors.forename: A
authors.initials: A
authors.lastname: Deriu
authors.affiliation: Heinz Maier-Leibnitz Zentrum, Technische Universität München, Lichtenbergstraße 1, Garching, Germany.
authors.forename: W
authors.initials: W
authors.lastname: Lohstroh
authors.affiliation: Dept. of Medical Biotechnologies and Traslational Medicine, University of Milano, LITA, Via Fratelli Cervi, 93, 20090 Segrate, Italy.
authors.forename: E
authors.initials: E
authors.lastname: Del Favero
authors.affiliation: Dept. of Medical Biotechnologies and Traslational Medicine, University of Milano, LITA, Via Fratelli Cervi, 93, 20090 Segrate, Italy.
authors.forename: M
authors.initials: M
authors.lastname: Corti
authors.affiliation: Dept. of Medical Biotechnologies and Traslational Medicine, University of Milano, LITA, Via Fratelli Cervi, 93, 20090 Segrate, Italy.
authors.forename: L
authors.initials: L
authors.lastname: Cantu'
mesh_terms: D004058:Diffusion; D004548:Elasticity; D005677:G(M1) Ganglioside / Q000737:chemistry*; D060328:Magnetic Phenomena; D008823:Micelles; D033363:Neutron Diffraction; D066244:Proton Magnetic Resonance Spectroscopy; D013059:Spectrum Analysis, Raman; D013499:Surface Properties; D013997:Time Factors; D014867:Water / Q000737:chemistry*
chemical_list: D008823:Micelles; D014867:Water; D005677:G(M1) Ganglioside
keywords: Depolarized Rayleigh Scattering; Gangliosides; NMR; OH-exchange rate; Quasielastic Neutron Scattering; Raman Scattering; Sugar/water interactions; Water structuring