SOLID-STATE NMR METHODS FOR STRUCTURAL STUDIES OF PHOSPHOLIPASE C

这个子项目是许多研究子项目中的一个 由NIH/NCRR资助的中心赠款提供的资源。子项目和 研究者（PI）可能从另一个NIH来源获得了主要资金， 因此可以在其他CRISP条目中表示。所列机构为 研究中心，而研究中心不一定是研究者所在的机构。 尽管最近成功地通过X射线晶体学和溶液核磁共振光谱的膜蛋白的结构表征，这些研究仍然是一个挑战，由于固有的不溶性和许多膜相关蛋白的结晶困难。因此，我们对膜蛋白的结构和功能的了解仍然很少。特别是，结构变化与激活外周膜蛋白的非底物脂质，这是至关重要的酶活性的这些蛋白质，不了解在原子水平上，因为缺乏实验方法来探测特定的蛋白质-脂质相互作用。 在这个试点项目中，我们将开发新的魔角旋转固态核磁共振技术来研究外周膜蛋白的结构和功能。特别是，将建立二维和三维实验，直接探测脂质-蛋白质相互作用。这些实验将在来自苏云金芽孢杆菌的磷脂酰肌醇特异性磷脂酶C（PI-PLC）上进行测试。随着新的方法在手，PI-PLC的界面活化的结构基础将被检查。这些努力代表了我们的长期目标，阐明生物医学重要的人类磷脂酶的结构和机制的第一步。

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. Despite the recent successes in structural characterization of membrane proteins by X-ray crystallography and solution NMR spectroscopy, these studies remain a challenge due to the inherent insolubility and difficulties in crystallization of many of membrane-associated proteins. As the result, our knowledge about the architecture and function of membrane proteins remains sparse. In particular, structural changes associated with activation of peripheral membrane proteins by non-substrate lipids, which are critical for the enzymatic activity of these proteins, are not understood at the atomic level because of lack of experimental methods to probe specific protein-lipid interactions. In this pilot project, we will develop new magic angle spinning solid-state NMR based methods to study the structure and function of peripheral membrane proteins. In particular, two- and three-dimensional experiments will be established to probe directly lipid-protein interactions. These experiments will be tested on a phosphatidylinositol-specific phospholipase C (PI-PLC) from Bacillus thuringiensis. With the new methods in hand, the structural basis of the interfacial activation of PI-PLC will be examined. These efforts represent the first step toward our long-term goal to elucidate the structure and the mechanism of biomedically important human phospholipases.