XAS STUDIES OF CPD I INTERMEDIATES

CPD I 中间体的 XAS 研究

• 批准号: 6586802
• 负责人: MARTIN L KIRK
• 金额: $ 14.32万
• 依托单位: STANFORD UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2002
• 资助国家: 美国
• 起止时间: 2002-03-01 至 2003-02-28
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6586802
• 关键词: biomaterials; biomedical resource; enzymes; proteins; spectrometry; structural biology

XAS studies are proposed for the trinuclear sites present in the multicopper oxidases. The fully reduced, fully oxidized and oxygen intermediate forms of native and type 1 mercury substituted laccase (Lc) will be investigated by EXAFS to probe for possible metal-metal interactions which would indicate oxygen bridging at the trinuclear site and to determine if a short Cu-O interaction is present in the first shell data on the intermediates. We will quantify the amount of Cu(I) present in both intermediates using the Cu K-edge structure. Peroxide and azide bound forms of T1Hg Lc, native Lc, and ascorbate oxidase (AO) will also be systematically studied by EXAFS and X-ray absorption edge methods to correlate spectroscopic results with crystallographic data on ligand bound forms of AO. These experiments are of critical importance in developing an understanding of the role of the trinuclear site in the four electron reduction of dioxygen to water. Finally XAS studies will be directed to ceruloplasmin (Cp) to probe the oxidation state of the coppers in the unusual (i.e. EPR nondetectable) trinuclear copper cluster which appears to be present in the resting form of this enzyme in rapid preparations and to elucidate the possible interactions among the trinuclear coppers as compared with other multicopper oxidases.

XAS研究提出的三核网站目前在 多铜氧化酶 完全还原，完全氧化和氧气 天然和1型汞取代漆酶的中间形式 (Lc)将由EXAFS进行研究，以探测可能的金属-金属 相互作用表明氧桥在三核 并确定是否存在短的Cu-O相互作用， 中间体的第一个外壳数据。 我们将量化 Cu（I）存在于使用Cu K-边结构的两种中间体中。 T1 Hg Lc、天然Lc和抗坏血酸盐的过氧化物和叠氮化物结合形式 氧化酶（AO）也将用EXAFS和X射线衍射进行系统的研究 吸收边方法，将光谱结果与 AO的配体结合形式的晶体学数据。 这些实验 对于理解人类的作用至关重要 三核位点的四电子还原的双氧， 水 最后，XAS研究将针对铜蓝蛋白（Cp）， 探测不寻常的（即EPR）中铜的氧化态 不可检测）三核铜簇，似乎存在 快速制备这种酶的静息形式，并 阐明三核铜之间可能的相互作用， 与其他多铜氧化酶相比。