Relat-Goberna Josep, Beedle Amy E M, Garcia-Manyes Sergi
Department of Physics and Randall Division of Cell and Molecular Biophysics, King's College London, Strand, London, WC2R 2LS, UK.
Small. 2017 Jun;13(24). doi: 10.1002/smll.201700147. Epub 2017 May 15.
The nanomechanics of lipid membranes regulates a large number of cellular functions. However, the molecular mechanisms underlying the plastic rupture of individual bilayers remain elusive. This study uses force clamp spectroscopy to capture the force-dependent dynamics of membrane failure on a model diphytanoylphosphatidylcholine multilayer stack, which is devoid of surface effects. The obtained kinetic measurements demonstrate that the rupture of an individual lipid bilayer, occurring in the bilayer parallel plane, is a stochastic process that follows a log-normal distribution, compatible with a pore formation mechanism. Furthermore, the vertical individual force-clamp trajectories, occurring in the bilayer orthogonal bilayer plane, reveal that rupturing process occurs through distinct intermediate mechanical transition states that can be ascribed to the fine chemical composition of the hydrated phospholipid moiety. Altogether, these results provide a first description of unanticipated complexity in the energy landscape governing the mechanically induced bilayer rupture process.
脂质膜的纳米力学调控着大量细胞功能。然而，单个双层膜塑性破裂背后的分子机制仍不清楚。本研究采用力钳光谱法来捕捉在无表面效应的二植烷酰磷脂酰胆碱多层堆栈模型上膜破坏的力依赖动力学。所获得的动力学测量结果表明，单个脂质双层膜在双层平行平面内发生的破裂是一个遵循对数正态分布的随机过程，这与孔形成机制相符。此外，在双层正交平面内发生的垂直单力钳轨迹表明，破裂过程通过不同的中间机械转变状态发生，这些状态可归因于水合磷脂部分的精细化学组成。总之，这些结果首次描述了在控制机械诱导双层膜破裂过程的能量景观中意想不到的复杂性。
