Electrochemical experiments define potentials associated with binding of substrates and inhibitors to nitrogenase MoFe protein.
Electrochemical experiments define potentials associated with binding of substrates and inhibitors to nitrogenase MoFe protein.
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DOI：
10.1039/d2fd00170e
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发表时间：
2023-07-19
影响因子：
3.4
通讯作者：
Vincent, Kylie A.
中科院分区：
文献类型：
--
作者：
Chen, Ting;Ash, Philip A.;Seefeldt, Lance C.;Vincent, Kylie A.
固氮酶催化氮的6电子还原为氨，在催化底物还原过程中经过一系列的氧化还原和质子化水平。钼铁固氮酶是研究最充分的，但与催化MoFe蛋白的氧化还原水平之间的质子耦合转换相关的氧化还原电位被证明很难确定，部分原因是从伙伴Fe蛋白到ATP-水解酶的复杂的电子转移途径。在这里，我们使用Eu(III/II)-配体对作为低电位氧化还原介体，对棕色固氮菌固氮酶的MOFE蛋白进行电化学控制。我们结合来自电化学电流响应的洞察力以及来自气相色谱和原位红外光谱的数据，以确定一系列抑制剂(一氧化碳、甲基异氰化物)与MoFe蛋白的金属催化位置结合的潜力，以及该酶对替代底物(质子和乙炔)的催化转化的开始。因此，我们将固氮酶抑制和催化的电位与氧化还原水平联系起来，这与生物固氮的难以捉摸的机制有关。通过电化学控制、气相色谱分析和原位红外光谱的结合，我们将电势与底物和抑制剂H+、C2H2、CO和MenC与固氮酶MoFe蛋白的结合联系起来。
Nitrogenases catalyse the 6-electron reduction of dinitrogen to ammonia, passing through a series of redox and protonation levels during catalytic substrate reduction. The molybdenum–iron nitrogenase is the most well-studied, but redox potentials associated with proton-coupled transformations between the redox levels of the catalytic MoFe protein have proved difficult to pin down, in part due to a complex electron-transfer pathway from the partner Fe protein, linked to ATP-hydrolysis. Here, we apply electrochemical control to the MoFe protein of Azotobacter vinelandii nitrogenase, using europium(iii/ii)-ligand couples as low potential redox mediators. We combine insight from the electrochemical current response with data from gas chromatography and in situ infrared spectroscopy, in order to define potentials for the binding of a series of inhibitors (carbon monoxide, methyl isocyanide) to the metallo-catalytic site of the MoFe protein, and the onset of catalytic transformation of alternative substrates (protons and acetylene) by the enzyme. Thus, we associate potentials with the redox levels for inhibition and catalysis by nitrogenase, with relevance to the elusive mechanism of biological nitrogen fixation. We associate potentials with the binding of substrates and inhibitors, H+, C2H2, CO and MeNC, to nitrogenase MoFe protein by coupling electrochemical control with gas chromatography analysis and in situ infrared spectroscopy.
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DOI：
10.1002/anie.202015751
发表时间：
2021-03-08
期刊：
Angewandte Chemie (International ed. in English)
影响因子：
--
作者：
Buscagan TM;Perez KA;Maggiolo AO;Rees DC;Spatzal T
通讯作者：
Spatzal T
影响因子：
15
作者：
Danyal, Karamatullah;Inglet, Boyd S.;Vincent, Kylie A.;Barney, Brett M.;Hoffman, Brian M.;Armstrong, Fraser A.;Dean, Dennis R.;Seefeldt, Lance C.
通讯作者：
Seefeldt, Lance C.
DOI：
10.1016/0005-2728(73)90270-3
发表时间：
1973-01-01
期刊：
BIOCHIMICA ET BIOPHYSICA ACTA
影响因子：
--
作者：
HWANG, JC;CHEN, CH;BURRIS, RH
通讯作者：
BURRIS, RH
DOI：
10.1016/0304-4165(66)90383-7
发表时间：
1966-01-01
期刊：
BIOCHIMICA ET BIOPHYSICA ACTA
影响因子：
--
作者：
DILWORTH, MJ
通讯作者：
DILWORTH, MJ
影响因子：
56.9
作者：
Brown, Katherine A.;Harris, Derek F.;King, Paul W.
通讯作者：
King, Paul W.