Interaction forces and adhesion of supported myelin lipid bilayers modulated by myelin basic protein
Interaction forces and adhesion of supported myelin lipid bilayers modulated by myelin basic protein
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DOI：
10.1073/pnas.0813110106
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发表时间：
2009-03-03
影响因子：
11.1
通讯作者：
Israeiachvill, Jacob
中科院分区：
文献类型：
--
作者：
Min, Younjin;Kristiansen, Kai;Israeiachvill, Jacob
在不同的髓鞘碱性蛋白（MBP）表面覆盖度下，模拟髓鞘细胞质表面的支持脂质双层之间的力距测量表明，当膜上的每个负脂质可以与MBP上的正精氨酸或赖氨酸基团结合时，最大的粘附和最小的细胞质间距发生。在最佳脂质/蛋白质比例下，脂质和MBP上两性离子基团之间的疏水、范德华和弱偶极相互作用提供了额外的吸引力。当MBP减少时，黏附减少，细胞质空间肿胀；当MBP过高时，两层肿胀更大。过量的MBP在表面之间形成一种弱凝胶，在压缩时坍塌。髓磷脂的组织和正常功能可以通过物理非共价力来理解，这些非共价力在带电脂质和MBP之间的数量和比例的特定组合下得到优化。因此，粘附的丧失，可能导致脱髓鞘，可由MBP或阴离子脂质的过量或不足引起。
Force-distance measurements between supported lipid bilayers mimicking the cytoplasmic surface of myelin at various surface coverages of myelin basic protein (MBP) indicate that maximum adhesion and minimum cytoplasmic spacing occur when each negative lipid in the membrane can bind to a positive arginine or lysine group on MBP. At the optimal lipid/protein ratio, additional attractive forces are provided by hydrophobic, van der Waals, and weak dipolar interactions between zwitterionic groups on the lipids and MBP. When MBP is depleted, the adhesion decreases and the cytoplasmic space swells; when MBP is in excess, the bilayers swell even more. Excess MBP forms a weak gel between the surfaces, which collapses on compression. The organization and proper functioning of myelin can be understood in terms of physical noncovalent forces that are optimized at a particular combination of both the amounts of and ratio between the charged lipids and MBP. Thus loss of adhesion, possibly contributing to demyelination, can be brought about by either an excess or deficit of MBP or anionic lipids.