Protein-Containing Lipid Bilayers Intercalated with Size-Matched Mesoporous Silica Thin Films
Protein-Containing Lipid Bilayers Intercalated with Size-Matched Mesoporous Silica Thin Films
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DOI：
10.1021/acs.nanolett.6b04493
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发表时间：
2017-01-01
期刊：
影响因子：
10.8
通讯作者：
Andersson, Martin
中科院分区：
文献类型：
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作者：
Isaksson, Simon;Watkins, Erik B.;Andersson, Martin
蛋白质是许多生物过程中的关键成分，其中跨膜(跨膜)蛋白质执行的功能尤其需要研究。这是因为这类蛋白质需要被结合到代表其天然环境的脂质双层中，此外，许多实验条件也需要用于稳定和分析目的的固体支撑物。然而，由于蛋白质材料的相互作用和缺乏物理空间，固体支持底物可能会限制蛋白质的功能。在这项工作中，我们定制了一种介孔二氧化硅薄膜的孔径和孔序，以匹配跨膜蛋白人水通道蛋白4(HAQP4)的天然细胞膜排列。利用中子反射率(NR)，我们提供了衬底孔隙如何容纳hAQP4的巨大的水溶性结构域的证据，该结构域延伸到衬底的孔隙中，长度为7.2 nm。互补的表面分析工具，包括耗散监测的石英晶体微天平(QCM-D)和荧光显微镜，显示在介孔二氧化硅上成功地形成了含有蛋白质的支撑脂质双层(PSLB)，而在非多孔二氧化硅上pSLB的形成受到阻碍。此外，电子显微镜(TEM和SEM)、光散射(DLS和停流)和小角X射线散射(SAXS)被用来全面表征这种新型的有机-无机混合界面，这种界面的定制很可能普遍适用于改善包含水溶域的广泛的膜蛋白的功能和稳定性。
Proteins are key components in a multitude of biological processes, of which the functions carried out by transmembrane (membrane-spanning) proteins are especially demanding for investigations. This is because this class of protein needs to be incorporated into a lipid bilayer representing its native environment, and in addition, many experimental conditions also require a solid support for stabilization and analytical purposes. The solid support substrate may, however, limit the protein functionality due to protein material interactions and a lack of physical space. We have in this work tailored the pore size and pore ordering of a mesoporous silica thin film to match the native cell-membrane arrangement of the transmembrane protein human aquaporin 4 (hAQP4). Using neutron reflectivity (NR), we provide evidence of how substrate pores host the bulky water-soluble domain of hAQP4, which is shown to extend 7.2 nm into the pores of the substrate. Complementary surface analytical tools, including quartz crystal microbalance with dissipation monitoring (QCM-D) and fluorescence microscopy, revealed successful protein-containing supported lipid bilayer (pSLB) formation on mesoporous silica substrates, whereas pSLB formation was hampered on nonporous silica. Additionally, electron microscopy (TEM and SEM), light scattering (DLS and stopped-flow), and small-angle X-ray scattering (SAXS) were employed to provide a comprehensive characterization of this novel hybrid organic-inorganic interface, the tailoring of which is likely to be generally applicable to improve the function and stability of a broad range of membrane proteins containing water-soluble domains.