Physics Institute of the University Münster, Surface Science, Münster, Germany.
European Molecular Biology Laboratory (EMBL), Heidelberg, Germany.
Sci Rep. 2024 Oct 24;14(1):25192. doi: 10.1038/s41598-024-76797-w.
Membrane proteins tend to be difficult to study since they need to be integrated into a lipid bilayer membrane to function properly. This study presents a method to synthesize a macroscopically large and freely transportable membrane with integrated membrane proteins which is useful for studying membrane proteins and protein complexes in isolation. The method could serve as a blueprint for the production of larger quantities of functionalised membranes for integration into technical devices similar to the MinION DNA sequencer. It is possible to self-assemble larger biological membranes on solid surfaces. However, they cannot be removed from their solid support without destroying them. In transportable form, self-assembled membranes are limited to sizes of about 17 nm in nanodiscs. Here we electrospray a series of molecular layers onto the liquid surface of a buffer solution which creates a flat, liquid environment on the surface that directs the self-assembly of the membrane. This method enables us to experimentally control the membrane composition and to succeed in producing large membranes with integrated OmpG, a transmembrane pore protein. The technique is compatible with the assembly of membrane based protein complexes. Listeriolysin O and pneumolysin efficiently assemble into non-covalent membrane pore complexes of approximately 30 units or more within the surface layer.
膜蛋白往往难以研究，因为它们需要整合到脂质双层膜中才能正常发挥功能。本研究提出了一种合成具有整合膜蛋白的宏观、可自由运输膜的方法，该方法对于研究孤立的膜蛋白和蛋白复合物非常有用。该方法可以作为生产更多功能性膜的蓝图，以集成到类似于 MinION DNA 测序仪的技术设备中。在固体表面上，较大的生物膜可以自行组装。然而，如果不破坏它们，就无法将它们从固体载体上移除。在可运输形式下，自组装膜的尺寸限制在纳米盘的约 17nm 左右。在这里，我们将一系列分子层电喷雾到缓冲溶液的液面上，在表面上形成一个平坦的液体环境，从而指导膜的自组装。该方法使我们能够实验控制膜的组成，并成功地生产出具有整合 OmpG（一种跨膜孔蛋白）的大膜。该技术与基于膜的蛋白复合物的组装兼容。李斯特菌溶血素 O 和肺炎球菌溶血素能够在表面层内有效地组装成非共价的膜孔复合物，约 30 个或更多个单位。
