Department of Microbiology, Humboldt-Universität zu Berlin, Chausseestrasse 117, 10115 Berlin, Germany.
Chemphyschem. 2010 Apr 26;11(6):1107-19. doi: 10.1002/cphc.200901002.
[NiFe]-hydrogenases catalyze the oxidation of H(2) to protons and electrons. This reversible reaction is based on a complex interplay of metal cofactors including the Ni-Fe active site and several [Fe-S] clusters. H(2) catalysis of most [NiFe]-hydrogenases is sensitive to dioxygen. However, some bacteria contain hydrogenases that activate H(2) even in the presence of O(2). There is now compelling evidence that O(2) affects hydrogenase on three levels: 1) H(2) catalysis, 2) hydrogenase maturation, and 3) H(2)-mediated signal transduction. Herein, we summarize the genetic, biochemical, electrochemical, and spectroscopic properties related to the O(2) tolerance of hydrogenases resident in the facultative chemolithoautotroph Ralstonia eutropha H16. A focus is given to the membrane-bound [NiFe]-hydogenase, which currently represents the best-characterized member of O(2)-tolerant hydrogenases.
[NiFe]-氢化酶催化 H(2)氧化为质子和电子。这种可逆反应是基于金属辅因子的复杂相互作用，包括 Ni-Fe 活性位点和几个 [Fe-S]簇。大多数 [NiFe]-氢化酶的 H(2)催化对氧气敏感。然而，一些细菌中含有即使在 O(2)存在下也能激活 H(2)的氢化酶。现在有令人信服的证据表明，O(2)在三个层面上影响氢化酶：1）H(2)催化，2）氢化酶成熟，3）H(2)介导的信号转导。本文总结了与兼性化能自养菌 Ralstonia eutropha H16 中驻留的氢化酶的 O(2)耐受性相关的遗传、生化、电化学和光谱特性。重点介绍了膜结合的 [NiFe]-氢化酶，它目前是研究最多的耐 O(2)氢化酶。
