Iyer Aditya, Petersen Nils O, Claessens Mireille M A E, Subramaniam Vinod
Nanoscale Biophysics Group, FOM Institute AMOLF, Amsterdam, The Netherlands; Nanobiophysics Group, MESA+ Institute for Nanotechnology and MIRA Institute for Biomedical Technology and Technical Medicine, University of Twente, Enschede, The Netherlands.
Nanobiophysics Group, MESA+ Institute for Nanotechnology and MIRA Institute for Biomedical Technology and Technical Medicine, University of Twente, Enschede, The Netherlands; Department of Chemistry, University of Alberta, Edmonton, Alberta, Canada.
Biophys J. 2014 Jun 17;106(12):2585-94. doi: 10.1016/j.bpj.2014.05.001.
Interactions of monomeric alpha-synuclein (αS) with lipid membranes have been suggested to play an important role in initiating aggregation of αS. We have systematically analyzed the distribution and self-assembly of monomeric αS on supported lipid bilayers. We observe that at protein/lipid ratios higher than 1:10, αS forms micrometer-sized clusters, leading to observable membrane defects and decrease in lateral diffusion of both lipids and proteins. An αS deletion mutant lacking amino-acid residues 71-82 binds to membranes, but does not observably affect membrane integrity. Although this deletion mutant cannot form amyloid, significant amyloid formation is observed in the wild-type αS clusters. These results suggest that the process of amyloid formation, rather than binding of αS on membranes, is crucial in compromising membrane integrity.
单体α-突触核蛋白（αS）与脂质膜的相互作用被认为在引发αS聚集过程中起重要作用。我们系统地分析了单体αS在支持脂质双层上的分布和自组装情况。我们观察到，当蛋白质/脂质比高于1:10时，αS形成微米级聚集体，导致可观察到的膜缺陷以及脂质和蛋白质侧向扩散的降低。一个缺失71-82位氨基酸残基的αS缺失突变体与膜结合，但未明显影响膜的完整性。尽管这种缺失突变体不能形成淀粉样蛋白，但在野生型αS聚集体中观察到了显著的淀粉样蛋白形成。这些结果表明，淀粉样蛋白形成过程而非αS与膜的结合，在损害膜完整性方面至关重要。
