title: Observation of ice-like water layers at an aqueous protein surface.
abstract: We study the properties of water at the surface of an antifreeze protein with femtosecond surface sum frequency generation spectroscopy. We find clear evidence for the presence of ice-like water layers at the ice-binding site of the protein in aqueous solution at temperatures above the freezing point. Decreasing the temperature to the biological working temperature of the protein (0 °C to -2 °C) increases the amount of ice-like water, while a single point mutation in the ice-binding site is observed to completely disrupt the ice-like character and to eliminate antifreeze activity. Our observations indicate that not the protein itself but ordered ice-like water layers are responsible for the recognition and binding to ice.
authors.affiliation: Foundation for Fundamental Research on Matter Institute for Atomic and Molecular Physics, 1098 XG Amsterdam, The Netherlands; K.Meister@amolf.nl.
authors.forename: Konrad
authors.initials: K
authors.lastname: Meister
authors.affiliation: Foundation for Fundamental Research on Matter Institute for Atomic and Molecular Physics, 1098 XG Amsterdam, The Netherlands;
authors.forename: Simona
authors.initials: S
authors.lastname: Strazdaite
authors.affiliation: Department of Animal Biology, University of Illinois at Urbana-Champaign, Urbana, IL 61801; and.
authors.forename: Arthur L
authors.initials: AL
authors.lastname: DeVries
authors.affiliation: Foundation for Fundamental Research on Matter Institute for Atomic and Molecular Physics, 1098 XG Amsterdam, The Netherlands;
authors.forename: Stephan
authors.initials: S
authors.lastname: Lotze
authors.affiliation: Department of Chemical Engineering and Chemistry and Institute for Complex Molecular Systems, Eindhoven University of Technology, 5600 MB Eindhoven, The Netherlands.
authors.forename: Luuk L C
authors.initials: LL
authors.lastname: Olijve
authors.affiliation: Department of Chemical Engineering and Chemistry and Institute for Complex Molecular Systems, Eindhoven University of Technology, 5600 MB Eindhoven, The Netherlands.
authors.forename: Ilja K
authors.initials: IK
authors.lastname: Voets
authors.affiliation: Foundation for Fundamental Research on Matter Institute for Atomic and Molecular Physics, 1098 XG Amsterdam, The Netherlands;
authors.forename: Huib J
authors.initials: HJ
authors.lastname: Bakker
mesh_terms: D021301:Antifreeze Proteins / Q000737:chemistry* / Q000235:genetics; D003460:Crystallization; D007053:Ice; D007834:Lasers; D013058:Mass Spectrometry / Q000379:methods; D008958:Models, Molecular; D009154:Mutation / Q000235:genetics; D013696:Temperature; D014867:Water / Q000737:chemistry*
chemical_list: D021301:Antifreeze Proteins; D007053:Ice; D014867:Water
keywords: antifreeze proteins; protein hydration; sum frequency generation