XAS OF MOLYBDENUM ENZYMES

这个子项目是利用资源的许多研究子项目之一。 由NIH/NCRR资助的中心拨款提供。对子项目的主要支持 子项目的首席调查员可能是由其他来源提供的， 包括美国国立卫生研究院的其他来源。为子项目列出的总成本可能 表示该子项目使用的中心基础设施的估计数量， 不是由NCRR赠款提供给次级项目或次级项目工作人员的直接资金。 钼是已知的唯一对人类必需的第二排过渡元素。它是非常大量的生物过程所需要的，它的重要性正日益被认识到。自从13年前第一个结构出版以来。目前的生物信息库包含约171个条目，分子名称中含有钼或钼蝶呤(不包括固氮酶蛋白质)，现在每个主要类别和类型的钼酶都有多种结构可用。这些丰富的结构信息使该领域发生了革命性的变化，并在很大程度上刺激了该领域的发展，但仍有许多悬而未决的问题，特别是关于钼中心的详细结构和催化机理的性质。我们提出的计划的目标是为钼酶所使用的催化机制建立一个深入的定量结构和电子基础，并在不同家族之间和内部进行比较。我们将主要使用X射线吸收光谱(XAS)来研究活性中心的物理和电子结构，在许多情况下，我们将应用整体方法，将来自XAS的信息、密度泛函理论(DFT)和现有的晶体结构数据相结合，以提供迄今最准确的活性中心图像。这种整体方法原则上适用于任何金属，因此它的发展对金属酶的研究具有广泛的意义。

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. Primary support for the subproject and the subproject's principal investigator may have been provided by other sources, including other NIH sources. The Total Cost listed for the subproject likely represents the estimated amount of Center infrastructure utilized by the subproject, not direct funding provided by the NCRR grant to the subproject or subproject staff. Molybdenum is the only second-row transition element known to be essential for humans. It is required for a very large number of biological processes, and its importance is increasingly being realized. Since the publication of the first structure thirteen years ago. The current PDB contains some 171 entries containing molybdenum or molybdopterin in the molecule name (excluding the nitrogenase proteins), and multiple structures are now available for every major category and type of Mo enzyme. This wealth of structural information has revolutionized and considerably stimulated the field, but many open questions remain, particularly concerning the detailed structure of the molybdenum site and the nature of the catalytic mechanisms. The goal of our proposed program is to develop an in-depth quantitative structural and electronic basis for the catalytic mechanisms used by Mo enzymes, and to compare and contrast them between and within the different families. We will primarily employ x-ray absorption spectroscopy (XAS) to investigate the physical and electronic structure of the active sites, and in many cases we will apply a holistic approach, which will combine information from XAS, density functional theory (DFT), and available crystal structure data to provide the most accurate picture yet of the active site. This holistic approach is in principal applicable to any metal, so its development has broad implications for metalloenzyme studies.