Kitadai Norio, Nakamura Ryuhei, Yamamoto Masahiro, Okada Satoshi, Takahagi Wataru, Nakano Yuko, Takahashi Yoshio, Takai Ken, Oono Yoshi
Super-cutting-edge Grand and Advanced Research (SUGAR) Program, Institute for Extra-cutting-edge Science and Technology Avant-garde Research (X-star), Japan Agency for Marine-Earth Science and Technology (JAMSTEC), Yokosuka, Japan.
Earth-Life Science Institute, Tokyo Institute of Technology, Meguroku, Tokyo, Japan.
Commun Chem. 2021 Mar 17;4(1):37. doi: 10.1038/s42004-021-00475-5.
A prevailing scenario of the origin of life postulates thioesters as key intermediates in protometabolism, but there is no experimental support for the prebiotic CO fixation routes to thioesters. Here we demonstrate that, under a simulated geoelectrochemical condition in primordial ocean hydrothermal systems (-0.6 to -1.0 V versus the standard hydrogen electrode), nickel sulfide (NiS) gradually reduces to Ni, while accumulating surface-bound carbon monoxide (CO) due to CO electroreduction. The resultant partially reduced NiS realizes thioester (S-methyl thioacetate) formation from CO and methanethiol even at room temperature and neutral pH with the yield up to 35% based on CO. This thioester formation is not inhibited, or even improved, by 50:50 coprecipitation of NiS with FeS or CoS (the maximum yields; 27 or 56%, respectively). Such a simple thioester synthesis likely occurred in Hadean deep-sea vent environments, setting a stage for the autotrophic origin of life.
一种流行的生命起源假说认为硫酯是原始代谢中的关键中间体，但尚无实验证据支持硫酯的益生元二氧化碳固定途径。在此，我们证明，在原始海洋热液系统模拟的地电化学条件下（相对于标准氢电极，电压为-0.6至-1.0V），硫化镍（NiS）逐渐还原为镍，同时由于一氧化碳（CO）的电还原作用，其表面会积累一氧化碳。即使在室温及中性pH条件下，生成的部分还原的NiS也能实现由CO和甲硫醇生成硫酯（硫代乙酸甲酯），基于CO的产率高达35%。NiS与FeS或CoS以50:50比例共沉淀时，这种硫酯的形成不受抑制，甚至产率有所提高（最高产率分别为27%或56%）。如此简单的硫酯合成可能发生在冥古宙深海热液环境中，为生命的自养起源奠定了基础。
