The proton pumping stoichiometry of purified mitochondrial complex I reconstituted into proteoliposomes
The proton pumping stoichiometry of purified mitochondrial complex I reconstituted into proteoliposomes
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DOI：
10.1016/j.bbabio.2006.10.001
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发表时间：
2006-12-01
影响因子：
4.3
通讯作者：
Brandt, Ulrich
中科院分区：
文献类型：
--
作者：
Galkin, Alexander;Droese, Stefan;Brandt, Ulrich
辅酶Ⅱ：泛醌氧化还原酶（复合物I）是有氧电子传递中最大、最复杂的酶。它如何利用氧化还原能量将质子泵过生物能量膜的机制仍然不清楚。在这里，我们确定了泵的线粒体复合物I从严格的有氧酵母解脂耶氏酵母的化学计量。对于完整的线粒体，3.8H（->+）/2 e（-）的测量值表明，每氧化一个NADH就泵送四个质子。对于重组到蛋白脂质体中的纯化的复合物I，我们测量到非常相似的泵送化学计量3.6H（->+）/2 e（-）。这是第一次证明复合物I的质子泵在酶纯化后保持完全功能。(c)2006 Elsevier B. V.保留所有权利。
NADH:ubiquinone oxidoreductase (complex I) is the largest and most complicated enzyme of aerobic electron transfer. The mechanism how it uses redox energy to pump protons across the bioenergetic membrane is still not understood. Here we determined the pumping stoichiometry of mitochondrial complex I from the strictly aerobic yeast Yarrowia lipolytica. With intact mitochondria, the measured value of 3.8H(->+)/2e(-) indicated that four protons are pumped per NADH oxidized. For purified complex I reconstituted into proteoliposomes we measured a very similar pumping stoichiometry of 3.6H(->+)/2e(-). This is the first demonstration that the proton pump of complex I stayed fully functional after purification of the enzyme. (c) 2006 Elsevier B.V. All rights reserved.