Department of Theoretical Biophysics, Max Planck Institute of Biophysics , Max-von-Laue Straße 3, 60438 Frankfurt am Main, Germany.
Institute for Biophysics, Goethe University Frankfurt , 60438 Frankfurt am Main, Germany.
ACS Nano. 2017 Feb 28;11(2):1273-1280. doi: 10.1021/acsnano.6b05434. Epub 2017 Jan 24.
The fusion of lipid membranes is opposed by high energetic barriers. In living organisms, complex protein machineries carry out this biologically essential process. Here we show that membrane-spanning carbon nanotubes (CNTs) can trigger spontaneous fusion of small lipid vesicles. In coarse-grained molecular dynamics simulations, we find that a CNT bridging between two vesicles locally perturbs their lipid structure. Their outer leaflets merge as the CNT pulls lipids out of the membranes, creating an hourglass-shaped fusion intermediate with still intact inner leaflets. As the CNT moves away from the symmetry axis connecting the vesicle centers, the inner leaflets merge, forming a pore that completes fusion. The distinct mechanism of CNT-mediated membrane fusion may be transferable, providing guidance in the development of fusion agents, e.g., for the targeted delivery of drugs or nucleic acids.
脂质膜的融合受到高能量障碍的阻碍。在生物体中，复杂的蛋白质机器执行这一重要的生物学过程。在这里，我们表明跨膜碳纳米管（CNT）可以触发小脂质囊泡的自发融合。在粗粒分子动力学模拟中，我们发现，CNT 在两个囊泡之间桥接会局部扰动它们的脂质结构。当 CNT 将脂质从膜中拉出时，它们的外叶层合并，形成沙漏形的融合中间体，其内层叶仍保持完整。当 CNT 从连接囊泡中心的对称轴上移开时，内层叶融合，形成一个完成融合的孔。CNT 介导的膜融合的独特机制可能具有可转移性，为融合剂的开发提供了指导，例如用于药物或核酸的靶向递送。
