Land Henrik, Sekretareva Alina, Huang Ping, Redman Holly J, Németh Brigitta, Polidori Nakia, Mészáros Lívia S, Senger Moritz, Stripp Sven T, Berggren Gustav
Molecular Biomimetics, Department of Chemistry, Ångström Laboratory, Uppsala University Box 523 SE-75120 Uppsala Sweden
Physical Chemistry, Department of Chemistry, Ångström Laboratory, Uppsala University Box 523 SE-75120 Uppsala Sweden.
Chem Sci. 2020 Sep 21;11(47):12789-12801. doi: 10.1039/d0sc03319g.
[FeFe]-hydrogenases are known for their high rates of hydrogen turnover, and are intensively studied in the context of biotechnological applications. Evolution has generated a plethora of different subclasses with widely different characteristics. The M2e subclass is phylogenetically distinct from previously characterized members of this enzyme family and its biological role is unknown. It features significant differences in domain- and active site architecture, and is most closely related to the putative sensory [FeFe]-hydrogenases. Here we report the first comprehensive biochemical and spectroscopical characterization of an M2e enzyme, derived from . As compared to other [FeFe]-hydrogenases characterized to-date, this enzyme displays an increased H affinity, higher activation enthalpies for H/H interconversion, and unusual reactivity towards known hydrogenase inhibitors. These properties are related to differences in active site architecture between the M2e [FeFe]-hydrogenase and "prototypical" [FeFe]-hydrogenases. Thus, this study provides new insight into the role of this subclass in hydrogen metabolism and the influence of the active site pocket on the chemistry of the H-cluster.
[铁铁]氢化酶以其高氢周转速率而闻名，并在生物技术应用背景下得到深入研究。进化产生了大量具有广泛不同特征的不同亚类。M2e亚类在系统发育上与该酶家族先前表征的成员不同，其生物学作用尚不清楚。它在结构域和活性位点结构上有显著差异，并且与假定的传感[铁铁]氢化酶关系最为密切。在这里，我们报告了源自[具体来源未给出]的一种M2e酶的首次全面生化和光谱表征。与迄今为止表征的其他[铁铁]氢化酶相比，这种酶表现出更高的氢亲和力、更高的氢/氢相互转化活化焓以及对已知氢化酶抑制剂的异常反应性。这些特性与M2e[铁铁]氢化酶和“典型”[铁铁]氢化酶之间活性位点结构的差异有关。因此，本研究为该亚类在氢代谢中的作用以及活性位点口袋对H簇化学的影响提供了新的见解。
