Ribas-Carbo M, Wiskich J T, Berry J A, Siedow J N
Botany Department-DCMB Group, Duke University, Durham, North Carolina 27708-1000.
Arch Biochem Biophys. 1995 Feb 20;317(1):156-60. doi: 10.1006/abbi.1995.1148.
The redox poise of the ubiquinone pool during electron transfer in isolated soybean mitochondria has been compared using two different procedures: the rapid organic extraction of ubiquinone followed by quantification of the oxidized and reduced forms using high-pressure liquid chromatography and an electrochemical technique that measures ubiquinone reduction voltametrically. The goal of these studies was to rigorously test the use of the voltametric technique to monitor the redox status of ubiquinone during the course of mitochondrial electron transfer. The linear relationship between the two methods confirms the reliability of the data obtained with the voltametric technique; however, redox inactive pools of ubiquinone were detected with the HPLC technique. We also quantified the absolute amounts of the ubiquinone homologues ubiquinone-9 and ubiquinone-10 in mitochondria isolated from different soybean tissues and compared their behavior during electron transfer in the presence and absence of pyruvate, an allosteric effector of the cyanide-resistant electron transfer pathway. Both homologues belong to a common redox-active pool in the inner mitochondrial membrane. The results indicate that ubiquinone can be a limiting component of electron transfer through the cyanide-resistant pathway, particularly in roots where its concentration is much lower than in cotyledons.
快速有机提取泛醌，然后使用高压液相色谱法对氧化型和还原型进行定量；以及一种电化学技术，通过伏安法测量泛醌的还原。这些研究的目的是严格测试伏安技术在监测线粒体电子传递过程中泛醌氧化还原状态方面的应用。两种方法之间的线性关系证实了伏安技术所获数据的可靠性；然而，用高效液相色谱技术检测到了无氧化还原活性的泛醌池。我们还对从不同大豆组织分离的线粒体中泛醌同系物泛醌 -9 和泛醌 -10 的绝对量进行了定量，并比较了它们在存在和不存在丙酮酸（抗氰电子传递途径的变构效应剂）的情况下电子传递过程中的行为。两种同系物都属于线粒体内膜中一个共同的氧化还原活性池。结果表明，泛醌可能是通过抗氰途径进行电子传递的一个限制因素，特别是在根部，其浓度远低于子叶。
