MEMBRANE-POTENTIAL OF MITOCHONDRIA MEASURED WITH AN ELECTRODE SENSITIVE TO TETRAPHENYL PHOSPHONIUM AND RELATIONSHIP BETWEEN PROTON ELECTROCHEMICAL POTENTIAL AND PHOSPHORYLATION POTENTIAL IN STEADY-STATE
MEMBRANE-POTENTIAL OF MITOCHONDRIA MEASURED WITH AN ELECTRODE SENSITIVE TO TETRAPHENYL PHOSPHONIUM AND RELATIONSHIP BETWEEN PROTON ELECTROCHEMICAL POTENTIAL AND PHOSPHORYLATION POTENTIAL IN STEADY-STATE
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DOI：
10.1007/bf01868720
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发表时间：
1979-01-01
影响因子：
2.4
通讯作者：
KOBATAKE, Y
中科院分区：
文献类型：
--
作者：
KAMO, N;MURATSUGU, M;KOBATAKE, Y
[大鼠肝]线粒体的膜电位估计从积累的四苯基磷（TPP+），这是确定与TPP+选择性电极在本研究中开发的。介绍了该电极的制备方法和一些操作参数。分析了线粒体摄取TTP+和DDA+（二苄基二甲基铵）的动力学，TPP+渗透线粒体膜的速度约为DDA+的15倍。线粒体对TPP+和DDA+的最终蓄积量大致相等。对于状态-4线粒体，膜电位约为180 mV（内部负）。TPP+-摄取和O2消耗的同时测量表明，状态3和4之间的过渡是可检测的TPP+-电极的使用。在TPP+电极显示达到状态-4后，测量线粒体外磷酸化电位。从渗透阴离子乙酸根的分布测量跨膜的pH差，以计算质子电化学电势。线粒体外磷酸化电位与质子电化学电位的比值n接近3。当ATP在呼吸链停止的条件下水解时，该n值也为3。讨论了n = 3的含义。
The membrane potential of [rat liver] mitochondria was estimated from the accumulation of tetraphenyl phosphonium (TPP+), which was determined with the TPP+-selective electrode developed in the present study. The preparation and some operational parameters of the electrode were described. The kinetics for uptake by mitochondria of TTP+ and DDA+ (dibenzyldimethyl ammonium) were analyzed and TPP+ permeated the mitochondrial membrane about 15 times faster than DDA+. The final amounts of accumulation of TPP+ and DDA+ by mitochondria were approximately equal. For the state-4 mitochondria, the membrane potential was about 180 mV (interior negative). Simultaneous measurements of TPP+-uptake and O2 consumption showed that the transition between states 3 and 4 was detectable by use of the TPP+-electrode. After the TPP+-electrode showed that state-4 was reached, the extramitochondrial phosphorylation potential was measured. The difference in pH across the membrane was measured from the distribution of permeant anion, acetate, so as to calculate the proton electrochemical potential. The ratio of extramitochondrial phosphorylation potential to proton electrochemical potenital, n was close to 3. This value of n was also 3 when ATP was hydrolyzed under the condition that the respiratory chain was arrested. The implication that n = 3 was discussed.