XAS OF MOLYBDENUM ENZYMES

这个子项目是许多研究子项目中利用 资源由NIH/NCRR资助的中心拨款提供。子项目和 调查员(PI)可能从NIH的另一个来源获得了主要资金， 并因此可以在其他清晰的条目中表示。列出的机构是 该中心不一定是调查人员的机构。 钼是生命系统中唯一具有已知功能的第二排过渡元素。它在几乎所有生物的酶系统中发挥功能，从细菌到植物，再到无脊椎动物和哺乳动物。所有的钼酶都含有被一种不寻常的含硫辅因子结合的金属。尽管这些酶具有共同的结构元素，但在所催化的不同化学反应中都是引人注目的，尽管几乎所有的反应都是两电子氧化还原反应，其中一个氧原子转移到钼或从钼转移出来。钼酶的功能也是多种多样的；例如，它们在微生物呼吸、绿色植物的氮素吸收、控制昆虫眼睛颜色和人类健康方面发挥着重要作用。建议的工作是利用X射线吸收光谱对主要的钼酶家族进行系统的研究。将使用一种新的高分辨率方法，允许更详细地描述活动站点。这项工作的最终目标是对酶使用的催化机制进行深入的定量、结构和电子方面的了解，并在不同家族之间和内部进行比较。由此，我们希望加深对钼酶如何实现其显着的功能多样性的理解。

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.