Department of Chemistry, Stanford University , Stanford, California 94305-5012, United States.
Langmuir. 2013 Oct 1;29(39):12220-7. doi: 10.1021/la402537p. Epub 2013 Sep 16.
Solid-supported lipid bilayers are useful model systems for mimicking cellular membranes; however, the interaction of the bilayer with the surface can disrupt the function of integral membrane proteins and impede topological transformations such as membrane fusion. As a result, a variety of tethered or cushioned lipid bilayer architectures have been described, which retain the proximity to the surface, enabling surface-sensitive techniques, but physically distance the bilayer from the surface. We have recently developed a method for spatially separating a lipid bilayer from a solid support using DNA lipids. In this system, a DNA strand is covalently attached to a glass slide or SiO2 wafer, and giant unilamellar vesicles (GUVs) displaying the complement rupture to form a planar lipid bilayer tethered above the surface. However, the location of the patch is random, determined by where the DNA-GUV initially binds to its complement. To allow greater versatility and control, we sought a way to pattern tethered membrane patches. We present a method for creating spatially distinct tethered membrane patches on a glass slide using microarray printing. Surface-reactive DNA sequences are spotted onto the slide, incubated to covalently link the DNA to the surface, and DNA-GUVs patches are formed selectively on the printed DNA. By interfacing the bilayers with microfluidic flow cells, materials can be added on top of or fused into the membrane to change the composition of the bilayers. With further development, this approach would enable rapid screening of different patches in protein binding assays and would enable interfacing patches with electrical detectors.
固载脂质双层是模拟细胞膜的有用模型系统；然而，双层与表面的相互作用会破坏整合膜蛋白的功能，并阻碍如膜融合等拓扑转化。因此，已经描述了各种连接或缓冲脂质双层结构，它们保留了与表面的接近度，从而能够使用表面敏感技术，但从物理上使双层与表面隔开。我们最近开发了一种使用 DNA 脂质将脂质双层从固体支撑物上空间分离的方法。在这个系统中，一条 DNA 链共价连接到玻璃载玻片或 SiO2 晶片上，并且显示互补断裂的巨大单层囊泡 (GUV) 形成在表面上方的连接的平面脂质双层。然而，斑块的位置是随机的，由 DNA-GUV 最初与其互补物结合的位置决定。为了提供更大的多功能性和控制，我们寻求一种方法来对连接的膜斑块进行图案化。我们提出了一种使用微阵列印刷在玻璃载玻片上创建空间上不同的连接膜斑块的方法。表面反应性 DNA 序列被点样到载玻片上，孵育以共价连接 DNA 到表面上，并选择性地在打印的 DNA 上形成 DNA-GUV 斑块。通过将双层与微流控流动池接口，可以在膜顶部添加或融合材料以改变双层的组成。通过进一步开发，这种方法将能够在蛋白质结合测定中快速筛选不同的斑块，并能够将斑块与电检测器接口。
