XAS OF MOLYBDENUM ENZYMES

该子项目是利用 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来源获得主要资金， 因此可以在其他CRISP条目中表示。列出的机构是 中心，不一定是研究者的机构。 钼是唯一的第二行过渡元素，在生命系统中具有已知的功能。它在几乎所有生物的酶系统中发挥功能作用，从细菌到植物到无脊椎动物和哺乳动物。所有的钼酶都含有由一种不寻常的含硫辅因子结合的金属。尽管具有共同的结构元素，酶在催化的不同化学反应的范围内是显着的，尽管几乎所有都是双电子氧化还原反应，其中氧原子转移到钼或从钼转移。钼酶的功能作用也同样多样，例如，它们在微生物呼吸、绿色植物的氮吸收、控制昆虫眼睛颜色和人类健康中发挥重要作用。拟议的工作是一个系统的研究钼酶的主要家庭使用X-射线吸收光谱。将使用一种新的高分辨率方法，可以更详细地描述活动站点。这项工作的最终目标是对酶所使用的催化机制进行深入的定量结构和电子理解，并在不同家族之间和内部进行比较和对比。从这一点上，我们希望提高我们的了解钼酶如何实现其显着的功能多样性。

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 with a known function in living systems. It fulfills functional roles in enzyme systems in almost all living creatures, from bacteria through plants to invertebrates and mammals. The molybdenum enzymes all contain the metal bound by an unusual sulfur-containing cofactor. Despite possessing common structural elements, the enzymes are remarkable in the range of different chemical reactions that are catalyzed, although almost all are two-electron oxidation-reduction reactions in which an oxygen atom is transferred to or from the molybdenum. The functional roles filled by molybdenum enzymes are equally diverse; for example, they play essential roles in microbial respiration, in the uptake of nitrogen in green plants, in controlling insect eye color, and in human health. The proposed work is a systematic study of the major families of molybdenum enzymes using x-ray absorption spectroscopy. A new high-resolution approach will be used that allows the active sites to be described in much more detail. The ultimate goal of the work is to develop an in-depth quantitative structural and electronic understanding of the catalytic mechanisms used by the enzymes, and to compare and contrast them between and within the different families. From this we hope to improve our understanding of how molybdenum enzymes achieve their remarkable functional diversity.