Small and Mechanosensitive Membrane Proteins Studied with DNA-based Tools

项目摘要 膜蛋白（MP）是可以在膜表面和膜表面上发现的分子。 在所有细胞中。它们使重要的细胞功能，如运输水，盐和营养物质 穿过细胞膜，感知细胞的化学和物理环境， 细胞之间的通讯，细胞粘附和能量转换。国会议员在每一个 生理和传染性疾病，60%的FDA批准的药物分子靶向它们。 为了了解这些蛋白质的确切功能，它们在不同疾病中扮演什么角色，或者 在计算机中模拟新的潜在药物如何与MP相互作用， 需要首先发现MP的结构。由于MP天然嵌入脂质中 膜，它们不溶于水，因此解决它们的问题更具挑战性。 分子结构比较水溶性蛋白质。因此， 在大约8,000种人类MP中，已知的不到100种。 该提案将提供新的基于DNA的工具，这些工具将克服许多这些挑战， MP结构测定。为此，没有遗传功能的DNA分子被化学地 合成并自组装成环形DNA纳米结构。然后这些环可以 填充有脂质和MP，从而使MP可溶于水。此外，这些DNA脂质纳米盘 为MP提供天然的细胞膜样环境，这对于保持MP在 他们的生理状态通过利用化学DNA的可编程特性 合成和自组装，这些纳米盘的尺寸、化学和物理性质可以 以替代技术无法提供的精确度和易用性进行控制。这将是 特别适用于解决小MP或机械敏感MP的结构， 由细胞膜中的分子力和压力驱动。 预计这项研究中基于DNA的分子工具将克服目前的 MP结构测定的障碍，并提供当前分子工具 不能提供。因此，这项研究将使结构生物学、药理学 和病毒学，从而增强对MP相关疾病的理解和治疗。

PROJECT SUMMARY Membrane proteins (MPs) are molecules that can be found in membranes on the surface and the inside of all cells. They enable vital cellular functions such as transport of water, salts and nutrients across the membranes, sensing of the chemical and physical environment of the cell, communication between cells, cell adhesion and energy conversion. MPs play a role in every physiological and infectious disease and 60% of all FDA approved drug molecules target them. To understand how exactly these proteins function, what role they play in different diseases, or to simulate in a computer how new potential drugs would interact with MPs, the exact molecular structures of the MPs need to be discovered first. As MPs are naturally embedded in lipid membranes, they are not soluble in water and it is therefore much more challenging to solve their molecular structures compared water-soluble proteins. Consequently, the molecular structures of less than 100 out of ~8,000 human MPs are known. This proposal will provide new DNA-based tools that will overcome many of these challenges for MP structure determination. For this, DNA molecules without a genetic function are chemically synthesized and self-assembled into ring-shaped DNA nanostructures. These rings can then be filled with lipids and MPs, thus making MPs soluble in water. Moreover, these DNA-lipid nanodiscs provide a native cell-membrane-like environment for the MP, which is important to keep MPs in their native physiological state. By taking advantage of the programmable nature of chemical DNA synthesis, and self-assembly, the size, chemical and physical properties of these nanodiscs can be controlled with a precision and ease that alternative technologies do not provide. This will be particularly useful for solving the structures of small MPs or mechanosensitive MPs, which are actuated by molecular forces and stress in cell membranes. It is expected that the DNA-based molecular tools from this research will overcome current obstacles for MP structure determination and provide functionalities that current molecular tools cannot offer. This research will therefore enable discoveries in structural biology, pharmacology and virology, and thereby enhance the understanding and treatment of MP-associated diseases.