The Escherichia coli NADH:Ubiquinone Oxidoreductase (Complex I) Is a Primary Proton Pump but May Be Capable of Secondary Sodium Antiport*
The Escherichia coli NADH:Ubiquinone Oxidoreductase (Complex I) Is a Primary Proton Pump but May Be Capable of Secondary Sodium Antiport*
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大肠杆菌 NADH：泛醌氧化还原酶（复合物 I）是初级质子泵，但可能具有次级钠逆向转运功能*
DOI：
10.1074/jbc.m311242200
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发表时间：
2004
影响因子：
4.8
通讯作者：
T. Friedrich
中科院分区：
文献类型：
--
作者：
S. Stolpe;T. Friedrich
NADH：泛醌氧化还原酶（复合物I）将电子从NADH转移到泛醌与质子跨膜易位偶联。最近，它被证明，从肺炎克雷伯氏菌复合物I易位钠离子，而不是质子。实验证据表明，来自近亲大肠杆菌的复合物I也作为主要的钠泵工作。然而，用全细胞获得的数据显示存在NADH诱导的电化学质子梯度。此外，傅里叶变换红外光谱表明，氧化还原反应的E。大肠杆菌复合物I与氨基酸的质子化偶联。为了解决这个矛盾，我们测量了孤立的E。在磷脂中重构的大肠杆菌复合物I。我们发现，NADH：泛醌氧化还原酶活性不依赖于钠浓度。由于用荧光探针测量的电化学质子梯度，蛋白脂质体中复合物的氧化还原反应引起膜电位。信号对质子载体羰基氰间氯苯腙（CCCP），抑制剂杀粉蝶菌素A，二环己基二甲酰亚胺（DCCD）和阿米洛利衍生物敏感，但对钠离子载体ETH-157不敏感。此外，莫能菌素作为Na+/H+交换剂防止质子梯度的产生。因此，我们的数据表明，E. coli复合物I是主要的产电质子泵。然而，pH梯度的大小取决于钠浓度。讨论了配合物I的二次Na+/H+逆向转运能力。
The NADH:ubiquinone oxidoreductase (complex I) couples the transfer of electrons from NADH to ubiquinone with the translocation of protons across the membrane. Recently, it was demonstrated that complex I from Klebsiella pneumoniae translocates sodium ions instead of protons. Experimental evidence suggested that complex I from the close relative Escherichia coli works as a primary sodium pump as well. However, data obtained with whole cells showed the presence of an NADH-induced electrochemical proton gradient. In addition, Fourier transform IR spectroscopy demonstrated that the redox reaction of the E. coli complex I is coupled to a protonation of amino acids. To resolve this contradiction we measured the properties of isolated E. coli complex I reconstituted in phospholipids. We found that the NADH:ubiquinone oxidoreductase activity did not depend on the sodium concentration. The redox reaction of the complex in proteoliposomes caused a membrane potential due to an electrochemical proton gradient as measured with fluorescent probes. The signals were sensitive to the protonophore carbonyl cyanide m-chlorophenylhydrazone (CCCP), the inhibitors piericidin A, dicyclohexylcarbodi-imide (DCCD), and amiloride derivatives, but were insensitive to the sodium ionophore ETH-157. Furthermore, monensin acting as a Na+/H+ exchanger prevented the generation of a proton gradient. Thus, our data demonstrated that the E. coli complex I is a primary electrogenic proton pump. However, the magnitude of the pH gradient depended on the sodium concentration. The capability of complex I for secondary Na+/H+ antiport is discussed.
DOI：
10.1111/j.1432-1033.1994.tb19985.x
发表时间：
1994-01-15
期刊：
EUROPEAN JOURNAL OF BIOCHEMISTRY
影响因子：
--
作者：
FRIEDRICH, T;VANHEEK, P;WEISS, H
通讯作者：
WEISS, H
N,N-二环己基碳二亚胺对 NADH-泛醌还原酶活性的抑制以及这种抑制与各种生物体中能量偶联位点 1 的出现的相关性。
影响因子：
2.9
作者：
Yagi,T
通讯作者：
Yagi,T
影响因子：
2.9
作者：
Yagi, T;Matsuno-Yagi, A
通讯作者：
Matsuno-Yagi, A