Giant unilamellar vesicles electroformed from native membranes and organic lipid mixtures under physiological conditions
Giant unilamellar vesicles electroformed from native membranes and organic lipid mixtures under physiological conditions
复制标题
DOI：
10.1529/biophysj.107.116228
复制
发表时间：
2007-11-01
影响因子：
3.4
通讯作者：
Bagatolli, Luis A.
中科院分区：
文献类型：
--
作者：
Montes, L.-Ruth;Alonso, Alicia;Bagatolli, Luis A.
近年来，巨大的单层囊泡（GUVs）已成为化学家、生物学家和物理学家对生物膜的许多方面感兴趣的密切关注的对象。特别是，这种“细胞大小”模型系统允许使用荧光显微镜相关技术在单个囊泡水平上直接可视化特定的膜相关现象。然而，该模型系统缺乏两个与生物膜相关的特征：1)传统的guv制备目前需要非常低的盐浓度，因此无法在生理条件下进行实验；2)该模型系统缺乏膜成分的不对称性。在这里，我们首次证明了guv可以在生理离子强度下从天然膜或有机脂质混合物中使用基于电生成方法的新方案制备。此外，对于由天然膜组成的guv，我们发现膜蛋白和鞘糖脂在电形成后保持其自然取向。我们期望我们的结果对于重新审视在低盐或无盐条件下使用guv进行的大量研究结果具有重要意义。这些研究的结果包括人工细胞组装、膜力学性能、脂质结构域形成、膜蛋白在脂质结构域的划分、dna -脂质相互作用和界面酶的活性，这些研究可能会受到溶液中盐含量的影响。
In recent years, giant unilamellar vesicles (GUVs) have become objects of intense scrutiny by chemists, biologists, and physicists who are interested in the many aspects of biological membranes. In particular, this "cell size'' model system allows direct visualization of particular membrane-related phenomena at the level of single vesicles using fluorescence microscopy-related techniques. However, this model system lacks two relevant features with respect to biological membranes: 1), the conventional preparation of GUVs currently requires very low salt concentration, thus precluding experimentation under physiological conditions, and 2), the model system lacks membrane compositional asymmetry. Here we show for first time that GUVs can be prepared using anew protocol based on the electroformation method either from native membranes or organic lipid mixtures at physiological ionic strength. Additionally, for the GUVs composed of native membranes, we show that membrane proteins and glycosphingolipids preserve their natural orientation after electroformation. We anticipate our result to be important to revisit a vast variety of findings performed with GUVs under low-or no-salt conditions. These studies, which include results on artificial cell assembly, membrane mechanical properties, lipid domain formation, partition of membrane proteins into lipid domains, DNA-lipid interactions, and activity of interfacial enzymes, are likely to be affected by the amount of salt present in the solution.