Department of Applied Physics, Chalmers University of Technology, Gothenburg, Sweden.
J Am Chem Soc. 2011 Sep 7;133(35):14027-32. doi: 10.1021/ja204589a. Epub 2011 Aug 9.
Progress with respect to enrichment and separation of native membrane components in complex lipid environments, such as native cell membranes, has so far been very limited. The reason for the slow progress can be related to the lack of efficient means to generate continuous and laterally fluid supported lipid bilayers (SLBs) made from real cell membranes. We show in this work how the edge of a hydrodynamically driven SLB can be used to induce rupture of adsorbed lipid vesicles of compositions that typically prevent spontaneous SLB formation, such as vesicles made of complex lipid compositions, containing high cholesterol content or being derived from real cell membranes. In particular, upon fusion between the moving edge of a preformed SLB and adsorbed vesicles made directly from 3T3 fibroblast cell membranes, the membrane content of the vesicles was shown to be efficiently transferred to the SLB. The molecular transfer was verified using cholera toxin B subunit (CTB) binding to monosialoganglioside receptors (G(M1) and G(M3)), and the preserved lateral mobility was confirmed by spatial manipulation of the G(M1/M3)-CTB complex using a hydrodynamic flow. Two populations of CTB with markedly different drift velocity could be identified, which from dissociation kinetics data were attributed to CTB bound with different numbers of ganglioside anchors.
在复杂脂质环境（如天然细胞膜）中，对天然膜成分的富集和分离的进展一直非常有限。进展缓慢的原因可能与缺乏有效手段来生成由真实细胞膜制成的连续且横向流动支撑的脂质双层（SLB）有关。在这项工作中，我们展示了如何利用水力驱动的 SLB 的边缘来诱导吸附脂质囊泡的破裂，这些囊泡的组成通常阻止自发的 SLB 形成，例如由复杂脂质组成、含有高胆固醇含量或源自真实细胞膜的囊泡。特别是，在预先形成的 SLB 的移动边缘与直接从 3T3 成纤维细胞膜吸附的囊泡之间融合后，囊泡的膜内容物被证明可以有效地转移到 SLB 中。通过霍乱毒素 B 亚基（CTB）与单唾液酸神经节苷脂受体（G(M1)和 G(M3)）的结合验证了分子转移，并且通过使用流体动力学流动对 G(M1/M3)-CTB 复合物进行空间操作来确认保留的横向流动性。可以识别出两种具有明显不同漂移速度的 CTB 群体，根据离解动力学数据，它们归因于与不同数量的神经节苷脂锚定结合的 CTB。
