High power cw OPO laser for infrared multiphoton dissociation spectroscopy of biological complexes in the gas phase

非共价蛋白复合物的结合和解离是许多生物过程中的关键事件。这些配合物的结构和稳定性是由结合伙伴之间的许多力的协同作用以及与结合伙伴的溶剂壳相关的水分子的位移和重组决定的。理解这些力和它们所导致的结构具有根本和实用的意义。实现分子识别过程更完整描述的关键挑战是溶剂效应与固有溶质-溶质相互作用的分离。我们的实验室正在利用气相测量来解决这个重要而具有挑战性的问题。脱溶蛋白复合物的气相研究提供了直接探测分子间内在相互作用的机会，并间接地研究了溶剂在分子识别中的作用。许多特定的蛋白质复合物很容易从水溶液转移到气相使用电喷雾电离（ESI）。一旦进入气相，就可以使用各种基于质谱（MS）的技术来检测脱溶离子。本提案的目标是获得资金，以获得高功率连续波（cw） OPO激光器，对生物配合物的气相离子进行红外多重光解（IRMPD）光谱测量。在IRMPD光谱中，可调谐的红外辐射被用来分离分离的气体离子，碎片的程度是作为辐射波长的函数来测量的。通常，这些测量是使用傅里叶变换离子回旋共振质谱进行的，其中感兴趣的离子被隔离并在离子池内的超高真空中被捕获。我们将使用IRMPD光谱技术来研究各种非共价生物复合物的气相离子的高阶结构，以评估脱溶对结构和稳定性的影响。我们还将应用这项技术来探索离散脂质与膜蛋白复合物相互作用的本质，以确定脂质结构如何影响膜蛋白的结构和功能。

The association and dissociation of noncovalent protein complexes are critical events in many biological processes. The structure and stability of these complexes are determined by the concerted action of many forces between binding partners and from the displacement and reorganization of water molecules associated with the solvent shell of the binding partners. An understanding of these forces and the structures they lead to is of fundamental and applied interest. A key challenge to achieving a more complete description of the molecular recognition processes is the separation of the solvent effects from the intrinsic solute-solute interactions. Our laboratory is utilizing gas phase measurements to tackle this significant and challenging problem. Gas phase studies of desolvated protein complexes afford an opportunity to directly probe the intrinsic intermolecular interactions and, indirectly, the role of solvent in molecular recognition. Many specific protein complexes are readily transferred from aqueous solution to the gas phase using electrospray ionization (ESI). Once in the gas phase, the desolvated ions can be interrogated using a variety of mass spectrometry (MS)-based techniques. The goal of this proposal is to secure funds to acquire a high power continuous wave (cw) OPO laser to carry out infrared multiphotodissociation (IRMPD) spectroscopy measurements on gas phase ions of biological complexes. In IRMPD spectroscopy, tunable IR radiation is used to dissociate isolated gaseous ions and the extent of fragmentation is measured as a function of radiation wavelength. Typically, these measurements are carried out using Fourier-transform ion cyclotron resonance MS, wherein the ions of interest are isolated and trapped at ultra-high vacuum within the ion cell. We will use the IRMPD spectroscopy technique to investigate the higher order structure of the gas phase ions of a variety of noncovalent biological complexes to assess the influence of desovlation on structure and stability. We will also apply this technique to explore the nature of discrete lipid interactions with membrane protein complexes with the goal of establishing how lipid structure influences membrane protein structure and function.