Structural biology and high resolution studies of P-glycoprotein

描述（由申请方提供）：小鼠P-糖蛋白（Pgp）的最新X射线结构确定为3.8埃，确立了研究最多的哺乳动物多药耐药（MDR）转运蛋白之一的整体结构架构。然而，Pgp的结构只是了解其转运机制和潜在抑制作用的起点。显然，需要更高分辨率的结构沿着不同的构象和共晶结构，以了解与ATP水解偶联的转运的详细机制，为未来合理的药物设计铺平道路。我们建议（1）使用非常新的膜蛋白结晶技术和新型去污剂来扩展Pgp晶体的分辨率，以大大提高模型的精度，（2）确定Pgp在向内和向外构象中的额外构象，以绘制运输循环的结构轨迹，（3）确定两种经典的和临床上重要的化合物阿霉素和罗丹明的Pgp的共晶体结构，以了解多特异性底物结合，和（4）确定人Pgp或人源化形式的Pgp的X射线结构，这对未来的药物设计非常有用。 公共卫生相关性：P-糖蛋白在包括癌症和HIV在内的多种疾病的药物疗效和多药耐药性中起着重要作用。这个高影响力的项目将提供一个详细的分子结构基础，其运输机制。Pgp的结构将极大地促进未来开发新的药物来规避多药耐药。

DESCRIPTION (provided by applicant): The recent x-ray structure of mouse P-glycoprotein (Pgp) determined to 3.8 angstrom established the overall structural architecture of one of the most studied mammalian multidrug resistance (MDR) transporters. The structure of Pgp, however, is only a starting point for understanding its transport mechanism and potential inhibition. Clearly a higher resolution structure along with different conformations and co-crystal structures will be required to understand the detailed mechanism of transport coupled to ATP hydrolysis paving the way towards future rational drug design. We propose to (1) extend the resolution of Pgp crystals using very new membrane protein crystallization techniques and novel detergents to greatly improve the precision of the model, (2) determine additional conformations of Pgp both in the inward- and outward- facing conformations to map out the structural trajectories of the transport cycle, (3) determine the co-crystal structures of Pgp of two classical and clinically important compounds, doxorubicin and rhodamine, to understand poly-specific substrate binding, and (4) determine the x-ray structure of human Pgp or humanized version of Pgp, which will be very useful for drug design in the future. PUBLIC HEALTH RELEVANCE: P-glycoprotein plays a significant role in drug efficacy and multidrug resistance to several diseases, including cancer and HIV. This high-impact project will provide a detailed molecular structural basis underlying its transport mechanism. The structures of Pgp should greatly facilitate the development of new drugs to circumvent multidrug resistance in the future.