We present a new membrane mimetic system using a membrane softening detergent commonly known as Tween 80 (TW80), to form oriented systems for solid-state NMR applications. TW80 is a fatty acid ester (oleate) of sorbitan polyethoxylate and a mild non-ionic surfactant. Phosphatidylcholine (PC)/TW80 model membrane systems were characterized by solid-state NMR and FTIR spectroscopy. ³¹P and ²H NMR spectra showed that DMPC (14:0) and DPPC (16:0) self-assemble with TW80 to form oriented structures, and maintain alignment over a wide range of molar ratios and temperatures. The addition of lanthanide ions revealed that the membrane alignment can be flipped from parallel to perpendicular with respect to the magnetic field direction. Using ¹⁵N solid-state NMR and a labeled model transmembrane peptide, we showed that TW80-based membranes can be employed to determine the peptide orientation in the magnetic field, which is useful for structural determination. Altogether, our work showed that TW80 could be exploited for direct and efficient membrane protein extraction and to enhance membrane and membrane protein orientation without using a detergent removal step. This approach could be extended to a wide range of membranes including native ones.

我们提出了一种新的膜模拟系统，该系统使用一种通常称为Tween 80（TW80）的膜软化清洁剂来形成固态NMR应用的定向系统。TW80是脱水山梨糖醇聚乙氧基化物的脂肪酸酯（油酸酯）和温和的非离子表面活性剂。磷脂酰胆碱（PC）/ TW80模型膜系统通过固态NMR和FTIR光谱进行了表征。³¹ P和² H NMR光谱显示DMPC（14：0）和DPPC（16：0）与TW80自组装形成定向结构，并在较大的摩尔比和温度范围内保持排列。镧系离子的添加​​表明，膜取向可以相对于磁场方向从平行翻转成垂直。使用¹⁵在N固态NMR和标记的模型跨膜肽中，我们表明可以使用基于TW80的膜来确定肽在磁场中的取向，这对于结构确定是有用的。总而言之，我们的工作表明TW80可用于直接和有效的膜蛋白提取，并且无需使用去污剂去除步骤即可增强膜和膜蛋白的取向。这种方法可以扩展到包括天然膜在内的各种膜。