Artificial Hydrogenases Based on Cobaloximes and Heme Oxygenase
Artificial Hydrogenases Based on Cobaloximes and Heme Oxygenase
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DOI：
10.1002/cplu.201600218
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发表时间：
2016-10-01
期刊：
影响因子：
3.4
通讯作者：
Artero, Vincent
中科院分区：
文献类型：
--
作者：
Bacchi, Marine;Veinberg, Elias;Artero, Vincent
在血红素加氧酶（HO）的血红素结合口袋中插入钴胺肟催化剂，产生了在中性水溶液中具有H-2演化活性的人工氢化酶。利用紫外/可见光谱和EPR光谱对这些新型生物杂合体进行了纯化和表征。这些分析揭示了两种不同的结合构象的存在，从而分别为钴胺素提供了疏水和亲水环境。量子化学/分子力学对接计算发现，由于氨基酸残基的移动，结合袋具有开放和封闭的构象。含有{Co(dmgH)(2)} （dmgH(2)=二甲基甲氧基肟）催化中心的以ho为基础的生物杂交体，与单独的钴胺肟或类似的抹香鲸肌红蛋白加合物相比，其营业额增加了三倍。因此，本研究为进一步改进这类生物杂交种提供了坚实的基础，通过对宿主蛋白进行定点诱变，对第二和外部配位球进行精心设计的修饰。
The insertion of cobaloxime catalysts in the heme-binding pocket of heme oxygenase (HO) yields artificial hydrogenases active for H-2 evolution in neutral aqueous solutions. These novel biohybrids have been purified and characterized by using UV/visible and EPR spectroscopy. These analyses revealed the presence of two distinct binding conformations, thereby providing the cobaloxime with hydrophobic and hydrophilic environments, respectively. Quantum chemical/molecular mechanical docking calculations found open and closed conformations of the binding pocket owing to mobile amino acid residues. HO-based biohybrids incorporating a {Co(dmgH)(2)} (dmgH(2)=dimethylglyoxime) catalytic center displayed up to threefold increased turnover numbers with respect to the cobaloxime alone or to analogous sperm whale myoglobin adducts. This study thus provides a strong basis for further improvement of such biohybrids, using well-designed modifications of the second and outer coordination spheres, through site-directed mutagenesis of the host protein.