Phospholipid Membrane Formation Templated by Coacervate Droplets
Phospholipid Membrane Formation Templated by Coacervate Droplets
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DOI：
10.1021/acs.langmuir.1c01562
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发表时间：
2021-08-16
期刊：
影响因子：
3.9
通讯作者：
Keating, Christine D.
中科院分区：
文献类型：
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作者：
Cakmak, Fatma Pir;Marianelli, Allyson M.;Keating, Christine D.
我们报告的凝聚层支持的磷脂膜的形成，通过水合干燥的脂质膜在凝聚层液滴的存在下。凝聚支撑膜的特征在于荧光成像，偏振，标记的脂质，脂质淬灭实验和溶质摄取实验的光漂白后的荧光恢复。我们的研究结果与凝聚层周围存在脂质膜一致，许多液滴完全被连续的脂质双层所包裹。与在不存在凝聚体的情况下通过温和水合形成的传统巨脂质囊泡相比，凝聚体模板化的膜囊泡在尺寸、形状和表观层状性上更均匀。由于它们的完全凝聚模型细胞质，这些简单的人工细胞是大分子拥挤的，可以很容易地预先加载高浓度的蛋白质或核酸。在相同的群体中，除了具有完整脂质膜涂层的凝聚液滴之外，其他凝聚液滴涂覆有具有允许溶质进入的缺陷或孔的膜，并且一些涂覆有多层膜。膜周围的蛋白质为基础的凝聚液滴提供保护，从蛋白酶添加到外部解决方案。生产具有被模型膜包围的凝聚模型细胞质的人工细胞的简单性同时作为用于益生元原始细胞形成的潜在机制和对生物技术的吸引力是令人感兴趣的。我们预计，这种结构可以作为一种新型的模型系统，用于了解细胞内相和细胞或细胞器膜之间的相互作用，这涉及越来越多的过程，从神经传递到信号。
We report the formation of coacervate-supported phospholipid membranes by hydrating a dried lipid film in the presence of coacervate droplets. Coacervate-supported membranes were characterized by fluorescence imaging, polarization, fluorescence recovery after photobleaching of labeled lipids, lipid quenching experiments, and solute uptake experiments. Our findings are consistent with the presence of lipid membranes around the coacervates, with many droplets fully coated by what appear to be continuous lipid bilayers. In contrast to traditional giant lipid vesicles formed by gentle hydration in the absence of coacervates, the coacervate-templated membrane vesicles are more uniform in size, shape, and apparent lamellarity. Due to their fully coacervate model cytoplasm, these simple artificial cells are macromolecularly crowded and can be easily pre-loaded with high concentrations of proteins or nucleic acids. Within the same population, in addition to coacervate droplets having intact lipid membrane coatings, other coacervate droplets are coated with membranes having defects or pores that permit solute entry, and some are coated with multilayered membranes. Membranes surrounding protein-based coacervate droplets provided protection from a protease added to the external solution. The simplicity of producing artificial cells having a coacervate model cytoplasm surrounded by a model membrane is at the same time interesting as a potential mechanism for prebiotic protocell formation and appealing for biotechnology. We anticipate that such structures could serve as a new type of model system for understanding interactions between intracellular phases and cell or organelle membranes, which are implicated in a growing number of processes ranging from neurotransmission to signaling.