XAS STUDIES OF COBALAMIN

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。子项目和 研究者（PI）可能从另一个NIH来源获得了主要资金， 因此可在其他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。 钴胺素是许多酶反应中所需的辅因子，包括甲基钴胺素依赖性甲硫氨酸合酶和腺苷酰钴胺素依赖性甲基丙二酰辅酶A。这些酶被一氧化氮（NO）抑制，据信这是由于NO-钴胺素复合物的形成。 在这个建议中，结合XAS，蛋白质晶体学和时间依赖的DFT计算将被用来调查的几何和电子结构的钴胺素-NO相对于水和甲基钴。

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. Cobalamins are required cofactors in a number of enzyme reactions, including methyl cobalamin-dependent methionine synthase and adensoyl-cobalamin-dependent methyl malonyl-CoA mutase. These enzymes are inhibited by nitric oxide (NO), and it is believed that this is due to the formation of an NO-cobalamin complex. In this proposal, combined XAS, protein crystallography and time-dependent DFT calculations will be used to investigate the geometric and electronic structure of cobalamin-NO relative to that of aqua and methyl cobalamins.