Light-driven dinitrogen reduction catalyzed by a CdS:nitrogenase MoFe protein biohybrid
Light-driven dinitrogen reduction catalyzed by a CdS:nitrogenase MoFe protein biohybrid
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DOI：
10.1126/science.aaf2091
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发表时间：
2016-04-22
期刊：
影响因子：
56.9
通讯作者：
King, Paul W.
中科院分区：
文献类型：
--
作者：
Brown, Katherine A.;Harris, Derek F.;King, Paul W.
分解二氮（N-2）并还原成氨（NH3）是一个动力学复杂且具有能量挑战性的多步反应。在Haber-Bosch过程中，N-2还原在高温高压下完成，而固氮酶的N-2固定在环境条件下使用来自腺苷5 '-三磷酸（ATP）水解的化学能进行。我们表明，硫化镉（CdS）纳米晶体可用于光敏化固氮酶铁（MoFe）蛋白，其中光捕获取代ATP水解驱动酶还原N-2成NH3。在最适条件下，酶的周转率为75次/min，是固氮酶复合物ATP偶联反应速率的63%。固氮酶抑制剂（即，乙炔、一氧化碳和二氢）抑制N-2还原。CdS：MoFe蛋白质生物杂化物提供了实现光驱动的N-2还原为NH3的光化学模型。
The splitting of dinitrogen (N-2) and reduction to ammonia (NH3) is a kinetically complex and energetically challenging multistep reaction. In the Haber-Bosch process, N-2 reduction is accomplished at high temperature and pressure, whereas N-2 fixation by the enzyme nitrogenase occurs under ambient conditions using chemical energy from adenosine 5'-triphosphate (ATP) hydrolysis. We show that cadmium sulfide (CdS) nanocrystals can be used to photosensitize the nitrogenase molybdenum-iron (MoFe) protein, where light harvesting replaces ATP hydrolysis to drive the enzymatic reduction of N-2 into NH3. The turnover rate was 75 per minute, 63% of the ATP-coupled reaction rate for the nitrogenase complex under optimal conditions. Inhibitors of nitrogenase (i.e., acetylene, carbon monoxide, and dihydrogen) suppressed N-2 reduction. The CdS: MoFe protein biohybrids provide a photochemical model for achieving light-driven N-2 reduction to NH3.