Guo Maolin, Sulc Filip, Ribbe Markus W, Farmer Patrick J, Burgess Barbara K
Department of Molecular Biology and Biochemistry, University of California, Irvine, California 92697-2025, USA.
J Am Chem Soc. 2002 Oct 16;124(41):12100-1. doi: 10.1021/ja026478f.
Recently, it has been demonstrated that the [4Fe-4S] cluster of the Fe protein of nitrogenase from Azotobacter vinelandii can be reduced to an unprecedented all-ferrous state. In this work, the reduction potential for the formation of the all-ferrous state is measured by the reactions of the reduced and oxidized Fe protein with a variety of chemical redox active agents, and by mediated spectroelectrochemical titration. Redox titrations obtain a potential ca. -790 mV/NHE for the formation of the all-ferrous state, a value consistent with the chemical reactivity experiments and with recent theoretical calculations. At present, no known redox protein in A. vinelandii is capable of generating the all-ferrous Fe protein.
最近，已经证明来自棕色固氮菌的固氮酶铁蛋白的[4Fe-4S]簇可以被还原为前所未有的全亚铁状态。在这项工作中，通过还原和氧化的铁蛋白与各种化学氧化还原活性剂的反应以及通过介导的光谱电化学滴定来测量形成全亚铁状态的还原电位。氧化还原滴定得到形成全亚铁状态的电位约为-790 mV/NHE，该值与化学反应性实验和最近的理论计算一致。目前，棕色固氮菌中没有已知的氧化还原蛋白能够产生全亚铁铁蛋白。
