Neuronal activation by GPI-linked neuroligin-1 displayed in synthetic lipid bilayer membranes
Neuronal activation by GPI-linked neuroligin-1 displayed in synthetic lipid bilayer membranes
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DOI：
10.1021/la051243d
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发表时间：
2005-11-08
期刊：
影响因子：
3.9
通讯作者：
Groves, JT
中科院分区：
文献类型：
--
作者：
Baksh, MM;Dean, C;Groves, JT
我们的特点是，在体外，海马神经元细胞和二氧化硅微珠包被合成，流体，脂质双层膜含有糖基磷脂酰肌醇（GPI）连接的细胞外结构域的突触后膜蛋白neuroligin-1之间的相互作用。这些双层-神经连接素-1珠激活神经元细胞以在接触点处形成突触前神经末梢，其方式类似于对异位表达全长神经连接素-1的活PC 12细胞所观察到的方式。合成膜在神经连接素-1密度接近1至6蛋白/μ m（2）时显示出生物活性。与神经连接素-1共价连接到表面的聚碳酸酯珠未能激活神经元，尽管事实上，神经连接素-1结合活性被保留。这意味着，脂质膜环境可能是必不可少的神经连接素-1的活动。该技术允许在具有类似于细胞表面的物理性质的环境中研究分离的蛋白质;蛋白质可以在膜内自由扩散，保持其在体内的取向，并且处于非变性状态。此外，合成膜环境提供了对脂质和蛋白质组成的控制。该技术易于实现，可应用于各种细胞研究。
We have characterized, in vitro, interactions between hippocampal neuronal cells and silica microbeads coated with synthetic, fluid, lipid bilayer membranes containing the glycosylphosphatidyl inositol (GPI)-linked extracellular domain of the postsynaptic membrane protein neuroligin-1. These bilayer-neuroligin-1 beads activated neuronal cells to form presynaptic nerve terminals at the point of contact in a manner similar to that observed for live PC 12 cells, ectopically expressing the full length neuroligin-1. The synthetic membranes exhibited biological activity at neuroligin-1 densities of similar to 1 to 6 proteins/mu m(2). Polyolycarbonate beads with neuroligin-1 covalently attached to the surface failed to activate neurons despite the fact that neuroligin-1 binding activity is preserved. This implies that a lipid membrane environment is likely to be essential for neuroligin-1 activity. This technique allows the study of isolated proteins in an environment that has physical properties resembling those of a cell surface; proteins can diffuse freely within the membrane, retain their in vivo orientations, and are in a nondenatured state. In addition, the synthetic membrane environment affords control over both lipid and protein composition. This technology is easily implemented and can be applied to a wide variety of cellular studies.