Stefaniu Cristina, Ries Annika, Gutowski Olof, Ruett Uta, Seeberger Peter H, Werz Daniel B, Brezesinski Gerald
Max Planck Institute of Colloids and Interfaces , Science Park Potsdam-Golm, 14476 Potsdam, Germany.
Georg-August-Universität Göttingen , Institute of Organic and Biomolecular Chemistry, Tammannstr. 2, 37077 Göttingen, Germany.
Langmuir. 2016 Mar 15;32(10):2436-44. doi: 10.1021/acs.langmuir.5b03830. Epub 2016 Mar 2.
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.
作为二维模型膜，已在软空气/水界面形成的单分子层中研究了三种具有重要生物学意义的半乳糖脑苷脂的分子相互作用。使用了高表面灵敏度技术，如掠入射X射线衍射（GIXD）、红外反射吸收光谱（IRRAS）和布鲁斯特角显微镜（BAM）。研究表明，化学结构上的微小差异对物理化学性质和分子间相互作用有显著影响。脂肪酸中2-d-羟基的存在有利于半乳糖脑苷脂C24:0（2-OH）单分子层在低侧向压力（<25 mN/m）下头基具有更高的水合状态，在高于30 mN/m时具有更高的凝聚效应。半乳糖脑苷脂C24:0和半乳糖脑苷脂C24:1表现出相反的行为，其分子间相互作用由弱水化但强氢键连接的相互连接头基定义。此外，与饱和化合物半乳糖脑苷脂C24:0相比，半乳糖脑苷脂C24:1脂肪酸链（神经酸）中的15-顺式双键稳定了LE相，但未干扰LC相的堆积参数。
