Determination of the intrinsic redox potentials of FeS centers of respiratory complex I from experimental titration curves.
Determination of the intrinsic redox potentials of FeS centers of respiratory complex I from experimental titration curves.
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DOI：
10.1016/j.bbabio.2010.05.011
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发表时间：
2010-09
影响因子：
4.3
通讯作者：
Stuchebrukhov, Alexei A.
中科院分区：
文献类型：
--
作者：
Medvedev, Emile S.;Couch, Vernon A.;Stuchebrukhov, Alexei A.
最近，Euro等人[Biochem.47，3185（2008）]报道了来自大肠杆菌的络合物I的九个FeS氧化还原中心中的七个的滴定数据。杆菌滴定数据的归属存在显著不确定性。其中4条滴定曲线被指定为N1 a、N1 b、N6 b和N2中心; 1条曲线被指定为N3或N7;另外1条曲线被指定为N4或N5;最后一条指示为Nx的曲线根本无法指定。此外，滴定数据对N6 b/N6 a对的归属也不确定。在本文中，使用我们计算的相互作用能[Couch et al. BBA 1787，1266（2009）]，我们对这些数据进行统计分析，考虑各种可能的分配，找到最佳拟合，并确定中心的固有氧化还原电位。在95%置信水平下，可以确定固有电位，其不确定度小于±10 mV，以进行最佳拟合分配。根据N6 b/N6 a滴定数据的归属，当N6 b-N2相互作用为71±14或96±26 mV时，理论滴定曲线与实验滴定曲线的一致性最好，这比预期的要好，可能表明N2中心与膜表面的距离较近。
Recently, Euro et al. [Biochem. 47, 3185 (2008)] have reported titration data for seven of nine FeS redox centers of complex I from E. coli. There is a significant uncertainty in the assignment of the titration data. Four of the titration curves were assigned to N1a, N1b, N6b, and N2 centers; one curve either to N3 or N7; one more either to N4 or N5; and the last one denoted Nx could not be assigned at all. In addition, the assignment of the titration data to N6b/N6a pair is also uncertain. In this paper, using our calculated interaction energies [Couch et al. BBA 1787, 1266 (2009)], we perform statistical analysis of these data, considering a variety of possible assignments, find the best fit, and determine the intrinsic redox potentials of the centers. The intrinsic potentials could be determined with uncertainty of less than ±10 mV at 95% confidence level for best fit assignments. We also find that the best agreement between theoretical and experimental titration curves is obtained with the N6b-N2 interaction equal to 71±14 or 96±26 mV depending on the N6b/N6a titration data assignment, which is stronger than was expected and may indicate a close distance of N2 center to the membrane surface.
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影响因子：
4.3
作者：
Couch, Vernon A.;Medvedev, Emile S.;Stuchebrukhov, Alexei A.
通讯作者：
Stuchebrukhov, Alexei A.
影响因子：
15
作者：
Alric, J;Lavergne, J;Nagashima, KVP
通讯作者：
Nagashima, KVP
影响因子：
4.3
作者：
Ohnishi, Tomoko;Nakamaru-Ogiso, Eiko
通讯作者：
Nakamaru-Ogiso, Eiko
影响因子：
3
作者：
Magnitsky, S;Toulokhonova, L;Ohnishi, T
通讯作者：
Ohnishi, T
影响因子：
4.3
作者：
Zickermann, Volker;Kerscher, Stefan;Zwicker, Klaus;Tocilescu, Maja A.;Radermacher, Michael;Brandt, Ulrich
通讯作者：
Brandt, Ulrich