title: Impact of Structural Differences in Galactocerebrosides on the Behavior of 2D Monolayers.
abstract: The molecular interactions of three biologically important galactocerebrosides have been studied in monolayers formed at the soft air/water interface as 2D model membranes. Highly surface-sensitive techniques as GIXD (grazing incidence X-ray diffraction), IRRAS (infrared reflection-absorption spectroscopy), and BAM (Brewster angle microscopy) have been used. The study reveals that small differences in the chemical structure have a relevant impact on the physical-chemical properties and intermolecular interactions. The presence of a 2-d-hydroxyl group in the fatty acid favored for GalCer C24:0 (2-OH) monolayers a higher hydration state of the headgroup at low lateral pressures (<25 mN/m) and a higher condensation effect above 30 mN/m. An opposite behavior was recorded for GalCer C24:0 and GalCer C24:1, for which the intermolecular interactions are defined by the weakly hydrated but strong H-bonded interconnected head groups. Additionally, the 15-cis-double bond in the fatty acid chain (nervonic acid) of GalCer C24:1 stabilized the LE phase but did not disturb the packing parameters of the LC phase as compared with the saturated compound GalCer C24:0.
authors.affiliation: Max Planck Institute of Colloids and Interfaces , Science Park Potsdam-Golm, 14476 Potsdam, Germany.
authors.forename: Cristina
authors.initials: C
authors.lastname: Stefaniu
authors.affiliation: Georg-August-Universität Göttingen , Institute of Organic and Biomolecular Chemistry, Tammannstr. 2, 37077 Göttingen, Germany.
authors.forename: Annika
authors.initials: A
authors.lastname: Ries
authors.affiliation: DESY , Forschungsbereich FS, Notkestr. 85, 22603 Hamburg, Germany.
authors.forename: Olof
authors.initials: O
authors.lastname: Gutowski
authors.affiliation: DESY , Forschungsbereich FS, Notkestr. 85, 22603 Hamburg, Germany.
authors.forename: Uta
authors.initials: U
authors.lastname: Ruett
authors.affiliation: Max Planck Institute of Colloids and Interfaces , Science Park Potsdam-Golm, 14476 Potsdam, Germany.|Freie Universität Berlin , Institute of Chemistry and Biochemistry, Arnimallee 22, 14195 Berlin, Germany.
authors.forename: Peter H
authors.initials: PH
authors.lastname: Seeberger
authors.affiliation: Technische Universität Braunschweig , Institute of Organic Chemistry, Hagenring 30, 38106 Braunschweig, Germany.
authors.forename: Daniel B
authors.initials: DB
authors.lastname: Werz
authors.affiliation: Max Planck Institute of Colloids and Interfaces , Science Park Potsdam-Golm, 14476 Potsdam, Germany.
authors.forename: Gerald
authors.initials: G
authors.lastname: Brezesinski