Communication of the H2-activating site with various protein and redox modules of [NiFe] hydrogenases

微生物代谢的一个关键的富含能量的底物是分子氢。由氢化酶催化的H2到电子和质子的酶促转化被认为是可能在古代生物中进化的早期能量耦合模式。该项目中提出的遗传、生物化学和光谱实验的预期数据将为绘制来自和去往H2活化NiFe-受体和各种受体/供体分子的双向电子和质子转移途径奠定基础。电子和质子转移之间的协调，进口和出口反应，通过共同或单独的渠道，并最终控制机制，引导电子流向H2摄取或H2生产的研究与细胞质NAD-还原氢化酶的真养产碱菌。H2氧化与呼吸链组分的直接偶联用A的膜结合氢化酶分析。真养型所选择的模型是有意义的，特别是因为[NiFe]氢化酶是由基本的功能模块，是保守的其他多电子氧化还原酶，如线粒体复合物I。

A key energy-rich substrate for microbial metabolism is molecular hydrogen. Enzymatic conversion of H2 into electrons and protons, catalyzed by hydrogenase, is considered as an early mode of energy coupling which may have been evolved in ancient organisms. The data expected from the genetic, biochemical and spectroscopic experiments proposed in this project will lay the groundwork for mapping bidirectional electron and proton transfer pathways from and to the H2 activating NiFe-metallocenter and various acceptor/donor molecules. Coordination between electron and proton transfer, import and export reactions that are guided through either common or separate channels and finally control mechanisms that steer the flow of electrons either towards H2 uptake or H2 production are investigated with the cytoplasmic NAD-reducing hydrogenase of Alcaligenes eutrophus. Direct coupling of H2 oxidation with components of the respiratory chain are analyzed with the membrane-bound hydrogenase of A. eutrophus. The selected models are significant in particular since [NiFe] hydrogenases are composed of elementary functional modules that are conserved in other multi-electron redox enzymes such as the mitochondrial complex I.