THE ACTIVE SITE OF [FE]- AND [NIFE]-HYDROGENASE

[FE]-和[NIFE]-氢化酶的活性位点

• 批准号: 8170250
• 负责人: WOLFRAM MEYER-KLAUCKE
• 金额: $ 0.03万
• 依托单位: STANFORD UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2010
• 资助国家: 美国
• 起止时间: 2010-05-01 至 2011-02-28
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8170250
• 关键词: Active Sites; Affinity; Binding; Binding Sites; Biological Sciences; Carbon; Carbon Monoxide; Chemical Structure; Chemicals; Coenzymes; Complex; Computer Retrieval of Information on Scientific Projects Database; Copper; Enzymes; Funding; Grant; Hydrogen; Hydrogenase; Institution; Ions; Iron; Lead; Ligand Binding; Ligands; Metals; Molecular; Pathway interactions; Reaction; Research; Research Personnel; Resources; Roentgen Rays; Site; Source; Sulfhydryl Compounds; United States National Institutes of Health; absorption; cofactor; electronic structure; hydroxypyridine; inhibitor/antagonist; iron hydrogenase; isocyanide; nickel-iron hydrogenase; research study

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. There are three phylogenetically different hydrogenases, [Fe]-, [NiFe]- and [FeFe]-hydrogenases, which catalyze activation of molecular hydrogen. [Fe]-hydrogenase is involved in hydrogenotrophic methanogenic pathway and harbors a unique iron-guanylyl pyridinol-cofactor. Its iron ion is complexed with two CO, one Cys-176-S, one N of the pyridinol ring and one acyl-C of the formyl-methyl substituent from the pyridinol ring. Crystal structure, chemical analysis, and infrared (IR)- and X-ray-absorption spectroscopic (XAS) analyses of this enzyme revealed the composition and geometry of the iron complex. However, to understand the detailed chemical- and electronic structures of the iron site in the catalytic reactions of [Fe]-hydrogenase, further analyses are required. One approach to this end is to analyze [Fe]-hydrogenase inhibited by its unique specific inhibitors. We have recently found that [Fe]-hydrogenase is inhibited by isocyanides, which are not known as the inhibitor of [NiFe]- and [FeFe]-hydrogenases. The affinity of these inhibitors is very high (Ki < 100 nM) (Shima et al. unpublished results). UV-Vis spectroscopic analysis indicated that isocyanides bind to the iron site. Fe K-edge XAS will characterize the coordination and electronic structure of the complex. Copper ions can also bind strongly to [Fe]-hydrogenase and inhibits this enzyme (Ki < 100 nM)Carbon monoxide as intrinsic ligands to iron in the active site of [Fe]-hydrogenase. In Metal-carbon bonds in enzymes and cofactors, Vol. 6 of Metal Ions in Life Sciences. Some IR experiments suggested that the copper ions bind to the iron complex. One of the candidates of the copper ions binding site might be the Cys176-thiol ligand bound to the iron. Cu K-Edge XAS will reveal the interaction of the copper ions with the thiol or the other part of the iron complex. These XAS analyses of [Fe]-hydrogenase-inhibitor complexes will lead to understanding of the mode of inhibition by these unique inhibitors and also give important information of the characters of

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， 因此可以在其他CRISP条目中表示。列出的机构为 研究中心，而研究中心不一定是研究者所在的机构。 存在三种遗传学上不同的氢化酶，[Fe]-、[NiFe]-和[FeFe]-氢化酶，其催化分子氢的活化。[Fe]-氢化酶参与氢营养产甲烷途径，并含有独特的铁鸟苷基吡啶醇辅因子。它的铁离子与两个CO、一个Cys-176-S、一个吡啶醇环的N和一个吡啶醇环上甲酰基-甲基取代基的酰基-C络合。该酶的晶体结构、化学分析以及红外（IR）和X射线吸收光谱（XAS）分析揭示了铁复合物的组成和几何形状。然而，要了解[Fe]-氢化酶催化反应中铁位点的详细化学和电子结构，需要进一步分析。为此目的的一种方法是分析[Fe]-氢化酶抑制其独特的特异性抑制剂。我们最近发现[Fe]-氢化酶被异腈类化合物抑制，异腈类化合物不是已知的[NiFe]-和[FeFe]-氢化酶的抑制剂。这些抑制剂的亲和力非常高（Ki < 100 nM）（Shima等人未发表的结果）。紫外-可见光谱分析表明，异氰化物结合到铁网站。Fe K边XAS谱表征了配合物的配位和电子结构。铜离子也可以与[Fe]-氢化酶强烈结合并抑制该酶（Ki < 100 nM）一氧化碳作为[Fe]-氢化酶活性位点中铁的固有配体。在酶和辅因子中的金属碳键，生命科学中的金属离子第6卷。一些红外实验表明铜离子与铁络合物结合。铜离子结合位点的候选者之一可能是与铁结合的Cys 176-巯基配体。Cu K-Edge XAS将揭示铜离子与硫醇或铁络合物的其他部分的相互作用。[Fe]-氢化酶-抑制剂复合物的这些XAS分析将有助于了解这些独特抑制剂的抑制模式，并提供有关[Fe]-氢化酶-抑制剂复合物特征的重要信息。