日本东京工业大学Ryuhei Nakamura研究团队的研究显示，硫化铜矿物通过联氨中间体进行非酶厌氧氨氧化。该项研究成果发表在2024年5月24日出版的《自然—化学》上。

据介绍，厌氧氨氧化(anammox)是一种利用亚硝酸盐激活氨的生物过程，它在海洋环境中产生了很大一部分氮气。然而，尽管经过几十年的生化研究，还没有发现能够厌氧氨氧化的合成模型。

在该研究中，课题组人员报道了一种硫化铜矿物复制了由三种金属酶催化的整个生物厌氧氨氧化途径。小组发现了一个铜-亚硝基铵{CuNO}₁₀配合物，由亚硝酸盐还原形成，作为铵氧化的氧化剂，导致亚硝酸盐和铵形成异解的N-N键。与生物过程类似，N₂的产生是由高活性的中间体肼介导的，肼是自然界中最有效的还原剂之一。

该课题组还发现了另一种途径，涉及N-N键异偶联形成杂化N₂O，这是一种具有独特同位素组成的强效温室气体。他们的研究代表了一个罕见的非酶促厌氧氨氧化反应的例子，该反应将非生物氮循环中的六个氧化还原状态相互连接。

附：英文原文

Title: Copper sulfide mineral performs non-enzymatic anaerobic ammonium oxidation through a hydrazine intermediate

Author: He, Daoping, Adachi, Kiyohiro, Hashizume, Daisuke, Nakamura, Ryuhei

Issue&Volume: 2024-05-24

Abstract: Anaerobic ammonium oxidation (anammox)—the biological process that activates ammonium with nitrite—is responsible for a significant fraction of N2 production in marine environments. Despite decades of biochemical research, however, no synthetic models capable of anammox have been identified. Here we report that a copper sulfide mineral replicates the entire biological anammox pathway catalysed by three metalloenzymes. We identified a copper–nitrosonium {CuNO}10 complex, formed by nitrite reduction, as the oxidant for ammonium oxidation that leads to heterolytic N–N bond formation from nitrite and ammonium. Similar to the biological process, N2 production was mediated by the highly reactive intermediate hydrazine, one of the most potent reductants in nature. We also found another pathway involving N–N bond heterocoupling for the formation of hybrid N2O, a potent greenhouse gas with a unique isotope composition. Our study represents a rare example of non-enzymatic anammox reaction that interconnects six redox states in the abiotic nitrogen cycle.

DOI: 10.1038/s41557-024-01537-6

Source: https://www.nature.com/articles/s41557-024-01537-6