ON THE MECHANISM OF [NIFE]-HYDROGENASES

[NIFE]-加氢酶的作用机制研究

• 批准号: 8170254
• 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/8170254
• 关键词: Adopted; Biological; Catalytic Domain; Computer Retrieval of Information on Scientific Projects Database; Consumption; Energy-Generating Resources; Enzymes; Funding; Grant; Hydrogen; Institution; Investigation; Ligands; Metals; Molecular; Mononuclear; Nature; Production; Proteins; Research; Research Personnel; Resources; Source; Staging; System; United States National Institutes of Health; X-Ray Crystallography; base; blind; catalyst; enzyme substrate; iron hydrogenase; nickel-iron hydrogenase; oxidation

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. Natures approach towards utilizing molecular hydrogen as an energy source is based on an own set of catalysts. Two of them which are termed as [FeFe] and [NiFe] hydrogenases contain binuclear metal cores as catalytic sites, whereas the third one termed [Fe] hydrogenase is mononuclear in origin. Though principal structural features of these enzymes have been obtained from protein crystallographic investigations important details of the catalytic mechanisms associated with biological hydrogen production or consumption are still not known. This lack of information is due to a particular problem: X-ray crystallography is practically blind for the substrate of these enzymes, e.g. for hydrogen atoms if they are coordinated to metal atoms or situated in their direct neighborship. Another lack of urgently needed information is associated with the [NiFe] hydrogenases which are isolated in oxidized unready stages. In the case of the Ni-B stage, a hydroxo or oxo ligand has been identified as a third bridge connecting Ni and Fe, but the exact bridging situation within the enzyme adopting the Ni-A stage is still the subject of a controversial debate due to oxidation damage of the enzyme. This damage results in a superposition of differently modified species, one of which is proposed as a hydroperoxo or peroxo bridge system which cannot be resolved unambiguously.

该副本是利用众多研究子项目之一 由NIH/NCRR资助的中心赠款提供的资源。子弹和 调查员（PI）可能已经从其他NIH来源获得了主要资金， 因此可以在其他清晰的条目中代表。列出的机构是 对于中心，这不一定是调查员的机构。 使用分子氢作为能源的天性方法是基于自己的一组催化剂。其中两个称为[FeFE]，[Nife]氢化酶含有双核金属核作为催化位点，而第三个称为[Fe]氢化酶的第三个位点是单核的。尽管这些酶的主要结构特征是从蛋白质晶体学研究中获得的，但仍然尚不清楚与生物氢或消耗相关的催化机制的重要细节。缺乏信息是由于一个特定的问题所致：X射线晶体学实际上是这些酶的底物的盲目性，例如对于氢原子，如果它们与金属原子协调或位于其直接邻居身份。另一个急需的信息缺乏信息与[Nife]氢化酶相关，这些氢酶在氧化的未准备就绪阶段分离出来。在Ni-B阶段的情况下，已经将羟或OXO配体确定为连接Ni和Fe的第三座桥，但是采用NI-A阶段的酶内的确切桥接情况仍然是由于酶的氧化损害而引起的争议性辩论的主题。这种损害导致了不同修饰物种的叠加，其中一种被提出为Hydroperoxo或Peroxo桥系统，无法明确解决。