Hu Yufang, Israelachvili Jacob
Department of Molecular and Medical Pharmacology and Department of Urology, David Geffen School of Medicine at UCLA, University of California-Los Angeles, Los Angeles, CA 90095, USA.
Colloids Surf B Biointerfaces. 2008 Mar 15;62(1):22-30. doi: 10.1016/j.colsurfb.2007.09.028. Epub 2007 Sep 29.
It has been speculated that adsorption of myelin basic protein (MBP) to the myelin lipid membrane leads to lateral reorganization of the lipid molecules within the myelin membrane. This hypothesis was tested in this study by surface pressure measurement and fluorescent imaging of a monolayer composed of a myelin lipid mixture. The properties of the lipid monolayer before and after addition of MBP into the subphase were monitored. Upon addition of MBP to the monolayer subphase, the surface pressure rose and significant rearrangement of the lipid domains was observed. These results suggest that binding and partial insertion of MBP into the lipid monolayer led to dramatic rearrangement and morphological changes of the lipid domains. A model of adsorption of MBP to the lipid domains and subsequent domain fusion promoted by minimization of electrostatic repulsion between the domains was proposed to account for the experimental observations. The significance of these results in light of the role of MBP in maintaining the myelin structural integrity is discussed.
据推测，髓鞘碱性蛋白（MBP）吸附到髓鞘脂质膜上会导致髓鞘膜内脂质分子的横向重组。本研究通过表面压力测量和由髓鞘脂质混合物组成的单层膜的荧光成像对这一假设进行了验证。监测了在亚相中添加MBP前后脂质单层膜的特性。当向单层膜亚相中添加MBP时，表面压力升高，并且观察到脂质域发生了显著重排。这些结果表明，MBP与脂质单层膜的结合及部分插入导致脂质域发生了剧烈重排和形态变化。提出了一个MBP吸附到脂质域以及随后通过域间静电斥力最小化促进域融合的模型来解释实验观察结果。讨论了这些结果鉴于MBP在维持髓鞘结构完整性中的作用的重要性。
