Impact of Structural Differences in Galactocerebrosides on the Behavior of 2D Monolayers

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• 作者：Cristina Stefaniu ; Annika Ries ; Olof Gutowski ; Uta Ruett ; Peter H. Seeberger ; Daniel B. Werz ; Gerald Brezesinski
• 刊名：Langmuir
• 出版年：2016
• 出版时间：March 15, 2016
• 年：2016
• 卷：32
• 期：10
• 页码：2436-2444
• 全文大小：631K
• ISSN：1520-5827

文摘

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.