标题： 使用双链型两性分子夹层剂在磷脂膜堆积中驱动响应性楔形结构 显示英文标题

标题： Driving a stimuli-responsive wedge in the packing of phospholipid membranes using bolaamphiphile intercalants

摘要： 两亲分子，其疏水尾部的两端具有极性基团，具有pH敏感的自发分子曲率，赋予极端微生物膜之间卓越的稳定性（或坚固性）与适应性（或可塑性）之间的平衡。 但 bolaamphiphiles 的存在（或实时插入）如何影响层状脂质膜尚不清楚。 我们结合时间分辨共聚焦荧光显微镜、原位小角X射线和中子散射（SAXS, SANS）以及中子自旋回波（NSE）测量，监测这里一种代表性 bolaamphiphile（一种由单个葡萄糖头基和C18:1（油酰）脂肪酸尾部组成的糖脂，G-C18:1）与基本上呈圆柱形、流体相的磷脂（二油酰磷脂酰胆碱，DOPC）膜的pH依赖性相互作用。 我们发现，在所有pH值下，两种介晶相会自发相互作用，产生大规模形态重塑。 在中性和酸性条件下，当 bolaamphiphile 呈现圆柱形时，囊泡彼此融合，产生内陷、内部管状结构和囊泡内囊泡聚集体。 相反，在碱性pH下，当羧酸去质子化且分子呈现倒锥形时，bolaamphiphile 会导致磷脂膜发生穿孔、出芽和囊泡形成。 这种不破坏基本双层结构的pH依赖性、环境敏感的膜重塑说明了局部分子层面的排列扰动如何转化为全局系统层面的形态变化，使膜能够获得环境敏感性和实时适应性。 这些结果支持了这样的观点，即分子通量（添加或移除两亲分子到生物膜中）可以赋予新的功能（例如pH敏感性），并影响细胞大小囊泡的整体形态。 显示英文摘要

摘要： Bolaamphiphilesamphiphilic molecules with polar groups at each of the two ends of a hydrophobic tail with pH-sensitive spontaneous molecular curvaturesendow membranes of extremophiles with an exquisite balance between stability (or robustness) and adaptability (or plasticity). But how the presence (or real-time insertion) of bolaamphiphiles influences lamellar lipid membranes is poorly understood. Using a combination of time-resolved confocal fluorescence microscopy, in situ small angle X-ray and neutron scattering (SAXS, SANS), and neutron spin echo (NSE) measurements, we monitor here the pH-dependent interactions of nanoscopic vesicles of a representative bolaamphiphilea glucolipid consisting of a single glucose headgroup and a C18:1 (oleyl) fatty acid tail (G-C18:1)with the membranes of an essentially cylindrical, fluid-phase phospholipid (dioleoylphosphatidylcholine, DOPC). We find that the two mesophases interact spontaneously at all pH values, producing large-scale morphological remodeling. Under neutral and acidic conditions, when the bolaamphiphile assumes a cylindrical shape, vesicles fuse with one another, producing invaginations, inner tubulation and vesicle-in-vesicle aggregates. Under basic pH, by contrast, when the carboxylic acid is deprotonated and the molecule is inverted-conical in shape, the bolaamphiphile causes phospholipid membranes to undergo poration, budding, and vesiculation. This pH-dependent, environmentally sensitive membrane remodeling without the disruption of the essential bilayer motif illustrates how local, molecular-level packing perturbations can translate into global system-level morphological changes, enabling membranes to acquire environmental sensitivity and real-time adaptability. These results support the notion that molecular fluxeswhich add (or remove) amphiphilic molecules to biological membranescan endow de novo functionalities (e.g., pH sensitivity) and influence global morphologies of cell-sized vesicles.