Department of Applied Physics, Chalmers University of Technology, Gothenburg, Sweden.
Sci Rep. 2012;2:824. doi: 10.1038/srep00824. Epub 2012 Nov 8.
We present an amperometric study of content release from individual vesicles in an artificial secretory cell designed with the minimal components required to carry out exocytosis. Here, the membranes of the cell and vesicles are substituted for protein-free giant and large unilamellar vesicles respectively. In replacement of the SNARE-complex, the cell model was equipped with an analog composed of complimentary DNA constructs. The DNA constructs hybridize in a zipper-like fashion to bring about docking of the artificial secretory vesicles and following the addition of Ca(2+ )artificial exocytosis was completed. Exocytotic events recorded from the artificial cell closely approximate exocytosis in live cells. The results together with simulations of vesicular release demonstrate that the molecular flux in this model is attenuated and we suggest that this is the result of restricted diffusion through a semi-stable fusion pore or a partitioning of the signalling molecule out of the fused vesicle membrane.
我们呈现了一份关于人工分泌细胞中单个囊泡内容物释放的电流研究，该细胞设计采用了执行胞吐作用所需的最小成分。在这里，细胞膜和囊泡分别被无蛋白的巨囊泡和大单层囊泡取代。为了替代 SNARE 复合物，细胞模型配备了一种由互补 DNA 构建体组成的模拟物。这些 DNA 构建体以拉链式的方式杂交，使人工分泌囊泡对接，随后加入 Ca(2+)，完成人工胞吐作用。从人工细胞中记录的胞吐事件与活细胞中的胞吐作用非常相似。这些结果以及囊泡释放的模拟表明，该模型中的分子通量减弱，我们认为这是由于通过半稳定融合孔的受限扩散或信号分子从融合囊泡膜中分配出来所致。
