2016年4月24日/生物谷BIOON/--所有生物都氮元素来存活,但是已知地球上,仅有两种过程被用来打开氮气中的超强化学键,从而允许氮气经还原后转化为人类、动物和植物能够消化的含氮化合物。其中的一种过程是自然的从农业开始以来农民就依赖的细菌固氮过程。另外一种过程是一个世纪之前利用氮气和氢气制造氨气的哈柏过程(Haber-B?sch process),它引发肥料生产变革,促进全球食物供应史无前例的增加。 本文系生物谷原创编译整理,欢迎转载!点击 获取授权 。更多资讯请下载生物谷APP。 Light-driven dinitrogen reduction catalyzed by a CdS:nitrogenase MoFe protein biohybrid Katherine A. Brown1, Derek F. Harris2, Molly B. Wilker3,*, Andrew Rasmussen2, Nimesh Khadka2, Hayden Hamby3, Stephen Keable4, Gordana Dukovic3, John W. Peters4, Lance C. Seefeldt2, Paul W. King The splitting of dinitrogen (N2) and reduction to ammonia (NH3) is a kinetically complex and energetically challenging multistep reaction. In the Haber-Bosch process, N2 reduction is accomplished at high temperature and pressure, whereas N2 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 N2 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 N2 reduction. The CdS:MoFe protein biohybrids provide a photochemical model for achieving light-driven N2 reduction to NH3. |
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