Improving membrane protein crystallization

描述（由申请人提供）：用x射线晶体学测定膜蛋白结构的主要障碍之一是获得高质量的晶体。我们提出了两种新技术来提高我们获得膜蛋白晶体的能力。方法一：我们提出了一种通用的、高通量的方法来筛选与靶膜蛋白结合的化合物。这些化合物将稳定并可能使蛋白质变硬，从而提高结晶的机会。筛选方法包括一个简单的蛋白质稳定性测试。方法二：我们提出利用聚合蛋白模块驱动附着膜蛋白的结晶。我们已经证明，蛋白质模块可以诱导多种可溶性蛋白质的结晶，包括那些难以结晶的蛋白质。此外，该模块与洗涤剂兼容，初步测试表明，它可以驱动跨膜螺旋的结晶。我们计划进一步优化该蛋白质模块，并测试其产生一系列膜蛋白晶体的能力。健康相关性：许多疾病是由蛋白质功能异常引起的。蛋白质的功能与蛋白质所采用的复杂的三维形状密切相关。因此，了解蛋白质结构是一个重要的医学目标，这样我们就可以了解它们是如何工作的，以及当它们的功能在疾病中出现问题时，我们如何进行干预。这一建议旨在提高我们获得这一关键结构信息的速度。

DESCRIPTION (provided by applicant): One the primary barriers to membrane protein structure determination by x-ray crystallography is obtaining high quality crystals. We propose two new technologies to improve our ability to obtain crystals of membrane proteins. Method I: We propose a general, high-throughput method to screen for compounds that bind to a target membrane protein. The compounds will stabilize and possibly rigidify the protein, improving the chances of crystallization. The screening method involves a simple test for protein stability. Method II: We proposed to utilize a polymerizing protein module to drive the crystallization of an attached membrane protein. We have demonstrated that the protein module can induce the crystallization of a wide variety of soluble proteins, including those otherwise refractory to crystallization. Moreover, the module is compatible with detergents and preliminary tests indicate that it can drive the crystallization of a transmembrane helix. We plan to further optimize this protein module and test its ability to produce crystals of a range of membrane proteins. Health Relevance: Many diseases are caused by aberrant protein function. Protein function is intimately tied to the elaborate three-dimensional shapes that proteins adopt. It is therefore an important medical goal to learn protein structures so that we can understand how they work and how we can intervene when their functions go awry in disease. This proposal seeks to increase the rate at which we can obtain this critical structural information.