School of Physics and Astronomy, University of Leeds, Leeds, LS2 9JT, United Kingdom.
Biointerphases. 2008 Jun;3(2):FA59. doi: 10.1116/1.2896113.
Solid-supported bilayer lipid membranes (SBLMs) containing membrane protein have been generated through a simple lipid dilution technique. SBLM formation from mixtures of native Escherichia coli bacterial inner membrane (IM) vesicles diluted with egg phosphatidylcholine (egg PC) vesicles has been explored with dissipation enhanced quartz crystal microbalance (QCM-D), atomic force microscopy (AFM), attenuated total internal-reflection Fourier-transform infrared spectroscopy (ATR-FTIR), and fluorescence recovery after photobleaching (FRAP). QCM-D studies reveal that SBLM formation from vesicle mixtures ranging between 0% and 100% IM can be divided into two regimes. Samples with < or = 40% IM form SBLMs, while samples of greater IM fractions are dominated by vesicle adsorption. FRAP experiments showed that the bilayers formed from mixed vesicles with < or = 40% IM were fluid, and comprised a mixture of both egg PC and IM. ATR-FTIR measurements on SBLMs membranes formed with 30% IM confirm that protein is present. SBLM formation was also explored as a function of temperature by QCM-D and FRAP. For samples of 30% IM, QCM-D data show a decreased mass and viscoelasticity at elevated temperatures, and an increased fluidity is observed by FRAP measurements. These results suggest improved biomimetic characteristics can be obtained by forming and maintaining the system at, or close to, 37 degrees C.
通过简单的脂质稀释技术生成了含有膜蛋白的固载双层脂质膜（SBLM）。用耗散增强石英晶体微天平（QCM-D）、原子力显微镜（AFM）、衰减全内反射傅里叶变换红外光谱（ATR-FTIR）和光漂白后荧光恢复（FRAP）研究了用天然大肠杆菌细菌内膜（IM）囊泡与卵磷酯（egg PC）囊泡稀释的混合物形成 SBLM 的情况。QCM-D 研究表明，从 0%到 100%的 IM 囊泡混合物形成 SBLM 可分为两个阶段。含有 <= 40%的 IM 的样品形成 SBLM，而含有更多 IM 部分的样品则主要由囊泡吸附。FRAP 实验表明，由混合囊泡形成的双层膜形成了 < = 40%的 IM，其是流体的，并且由 egg PC 和 IM 的混合物组成。ATR-FTIR 对含有 30%的 IM 的 SBLM 膜的测量证实了蛋白质的存在。通过 QCM-D 和 FRAP 还研究了 SBLM 形成作为温度的函数。对于 30%的 IM 样品，QCM-D 数据表明在升高的温度下质量和粘弹性降低，并且通过 FRAP 测量观察到流动性增加。这些结果表明，通过在 37°C 或接近 37°C 的温度下形成和维持系统，可以获得改善的仿生特性。
