[FeFe]-氢化酶是在各种细菌和藻类的微生物能量代谢中所涉及的金属酶，具有极强的催化性能，如果能将其转化成生成和利用燃料电池中的氢的一种手段的话将会极为有用。在这些酶中，催化发生在一个独特的“二铁”中心，它包含一个桥联“dithiolate”配体、三个CO配体和两个CN配体。在这篇论文中，作者发现，这一“二铁”中心的三个合成模仿物可以被加载到[FeFe]- 氢化酶成熟蛋白HydF上，然后转移给藻类变体apo-HydA1。HydA1的充分活化只有通过包含具有一个“azadithiolate”桥的模仿物的HydF杂合蛋白才能实现，从而证实了这一配体在native [FeFe]-氢化酶的活性点上的存在。这是采用一个特定蛋白支架与活性点合成类似物的组合来实现受控金属酶活化的第一个例子。（生物谷Bioon.com）
生物谷推荐英文摘要：
Nature doi:10.1038/nature12239
Biomimetic assembly and activation of [FeFe]-hydrogenases
G. Berggren, A. Adamska, C. Lambertz, T. R. Simmons, J. Esselborn, M. Atta, S. Gambarelli, J.-M. Mouesca, E. Reijerse, W. Lubitz, T. Happe, V.Artero & M. Fontecave
Hydrogenases are the most active molecular catalysts for hydrogen production and uptake and could therefore facilitate the development of new types of fuel cell. In [FeFe]-hydrogenases, catalysis takes place at a unique di-iron centre (the [2Fe] subsite), which contains a bridging dithiolate ligand, three CO ligands and two CN– ligands. Through a complex multienzymatic biosynthetic process, this [2Fe] subsite is first assembled on a maturation enzyme, HydF, and then delivered to the apo-hydrogenase for activation. Synthetic chemistry has been used to prepare remarkably similar mimics of that subsite1, but it has failed to reproduce the natural enzymatic activities thus far. Here we show that three synthetic mimics (containing different bridging dithiolate ligands) can be loaded onto bacterial Thermotoga maritima HydF and then transferred to apo-HydA1, one of the hydrogenases of Chlamydomonas reinhardtii algae. Full activation of HydA1 was achieved only when using the HydF hybrid protein containing the mimic with an azadithiolate bridge, confirming the presence of this ligand in the active site of native [FeFe]-hydrogenases. This is an example of controlled metalloenzyme activation using the combination of a specific protein scaffold and active-site synthetic analogues. This simple methodology provides both new mechanistic and structural insight into hydrogenase maturation and a unique tool for producing recombinant wild-type and variant [FeFe]-hydrogenases, with no requirement for the complete maturation machinery.
