Groningen Biomolecular Sciences and Biotechnology Institute, Department of Biophysical Chemistry, University of Groningen, Nijenborgh 4, 9747AG Groningen, The Netherlands.
Proc Natl Acad Sci U S A. 2010 Nov 16;107(46):19856-60. doi: 10.1073/pnas.1001316107. Epub 2010 Nov 1.
Mechano-sensitive channels are ubiquitous membrane proteins that activate in response to increasing tension in the lipid membrane. They facilitate a sudden, nonselective release of solutes and water that safeguards the integrity of the cell in hypo- or hyper-osmotic shock conditions. We have simulated the rapid release of content from a pressurized liposome through a particular mechano-sensitive protein channel, MscL, embedded in the liposomal membrane. We show that a single channel is able to relax the liposome, stressed to the point of bursting, in a matter of microseconds. We map the full activation-deactivation cycle of MscL in near-atomic detail and are able to quantify the rapid decrease in liposomal stress as a result of channel activation. This provides a computational tool that opens the way to contribute to the rational design of functional nano-containers.
机械敏感通道是普遍存在的膜蛋白，它们会在脂质膜张力增加时激活。在低渗或高渗休克条件下，它们促进溶质和水的突然、非选择性释放，从而保护细胞的完整性。我们通过模拟嵌入在脂质体膜中的特定机械敏感蛋白通道 MscL 来模拟内容物从加压脂质体中的快速释放。我们表明，单个通道能够在几微秒内使受到压力的脂质体松弛，达到破裂的临界点。我们以近乎原子的细节描绘了 MscL 的完整激活-失活循环，并能够量化通道激活导致的脂质体压力的快速下降。这为合理设计功能纳米容器提供了一种计算工具。
