XAS OF MOLYBDENUM ENZYMES

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。子项目及 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。 钼是已知的唯一对人类至关重要的第二行过渡元素。许多生物过程都需要它，它的重要性越来越被认识到。从13年前第一个结构出版以来。目前的PDB包含约171个在分子名称中含有钼或钼蝶呤的条目（不包括固氮酶蛋白），并且现在可以为每个主要类别和类型的Mo酶提供多种结构。这种丰富的结构信息已经彻底改变，并大大刺激了该领域，但许多悬而未决的问题仍然存在，特别是关于钼网站的详细结构和催化机制的性质。我们提出的计划的目标是开发一个深入的定量结构和电子基础的钼酶所使用的催化机制，并比较和对比它们之间和不同的家庭。我们将主要采用X射线吸收光谱（XAS）来研究活性位点的物理和电子结构，在许多情况下，我们将采用整体方法，该方法将联合收割机的XAS信息，密度泛函理论（DFT）和可用的晶体结构数据相结合，以提供活性位点的最准确的图像。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. 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. 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.