Probing the Electronic Structure of Fe-S Clusters

探究 Fe-S 团簇的电子结构

• 批准号: 6357557
• 负责人: LAI-SHENG WANG
• 金额: $ 18.63万
• 依托单位: WASHINGTON STATE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2001
• 资助国家: 美国
• 起止时间: 2001-08-01 至 2005-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6357557
• 关键词: active sites; chemical bond; dielectric property; electrical property; electron transport; electrospray ionization mass spectrometry; gas; intermolecular interaction; iron sulfur protein; mass spectrometry; metal complex; molecular shape; oxidation reduction reaction; photoelectron spectrometry; physical state; protein structure function

DESCRIPTION (provided by applicant): Iron-sulfur proteins are present in all living matter and represent one of the most distributed proteins in nature. They constitute a class of important biological electron transfer agents, but are increasingly found to have more biological functions. Their functionality is critically dependent on the electronic structure of their active sites and the influences imposed by the protein environment. The active sites most frequently consist of a one-Fe center, Fe(2)S(2), Fe(3)S(4), and Fe(4)S(4) clusters, usually coordinated by sulfur from the cysteine side chains of the surrounding proteins. Nature has evolved a diverse range of functionality with just the few Fe-S clusters through fine-tuning of the protein environment. It is thus crucial to understand the properties of the Fe-S clusters and modifications by their surroundings in order to understand the properties and functionalities of the iron-sulfur proteins. However, Fe-S clusters are extremely complicated electronic systems. This proposal seeks to experimentally probe, in the gas phase, the electronic structure and properties of the Fe-S clusters in their bare forms, in analog complexes, and in proteins. The gas phase investigations are free from the perturbation of solvents or crystal field, yields the intrinsic properties of the Fe-S clusters, and allows the influences of the protein environments to be probed directly. The experimental approaches in this proposal are unconventional, taking advantages of recent developments in biological mass spectrometry and gas-phase spectroscopic techniques. An electrospray ion source will be used to transport Fe-S clusters and proteins into the gas phase. Negatively charged ions of the Fe-S clusters and proteins will be interrogated by photodetachment photo-electron spectroscopy, which yields direct information about their electronic structures and intramolecular electrostatic interactions. Because photodetachment is analogous to an oxidation process, the proposed experiments will also yield energetic information relevant to redox reactions of Fe-S clusters. It is expected that the new experimental results from the proposed work will stimulate further theoretical advancements.

描述（由申请人提供）：铁硫蛋白存在于所有 生命物质，代表自然界中分布最广泛的蛋白质之一。 它们构成了一类重要的生物电子转移剂，但是 越来越多的人发现其具有更多的生物学功能。它们的功能 很大程度上取决于其活性位点的电子结构， 蛋白质环境的影响。活跃站点最多 通常由一 Fe 中心、Fe(2)S(2)、Fe(3)S(4) 和 Fe(4)S(4) 组成 簇，通常由半胱氨酸侧链的硫协调 周围的蛋白质。大自然已经进化出多种功能 通过蛋白质环境的微调，仅产生少数 Fe-S 簇。它 因此，了解 Fe-S 团簇的性质至关重要 周围环境的改变，以了解其属性和 铁硫蛋白的功能。然而，Fe-S团簇是 极其复杂的电子系统。该提案旨在通过实验 探针，在气相中，Fe-S的电子结构和性质 簇以其裸露形式、类似复合物和蛋白质形式存在。气体 物相研究不受溶剂或晶体的干扰 场，产生 Fe-S 团簇的固有特性，并允许 直接探测蛋白质环境的影响。实验的 该提案中的方法是非常规的，利用了最近的 生物质谱和气相光谱的发展 技术。电喷雾离子源将用于传输 Fe-S 簇 和蛋白质进入气相。 Fe-S 团簇的带负电离子 蛋白质将受到光分离光电子的询问 光谱学，产生有关其电子结构的直接信息 和分子内静电相互作用。因为光脱离是 类似于氧化过程，所提出的实验也将产生 与 Fe-S 簇的氧化还原反应相关的能量信息。这是 预计拟议工作的新实验结果将 推动理论的进一步发展。