Modulation of the kinetics and the steady-state level of intermediates of mitochondrial coupled reactions by inhibitors and uncouplers.
Modulation of the kinetics and the steady-state level of intermediates of mitochondrial coupled reactions by inhibitors and uncouplers.
复制标题
通过抑制剂和解偶联剂调节线粒体偶联反应的动力学和中间体的稳态水平。
DOI：
10.1021/bi00300a035
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发表时间：
1984
期刊：
影响因子：
2.9
通讯作者：
Hatefi,Y
中科院分区：
文献类型：
--
作者：
Yagi,T;Matsuno-Yagi,A;Vik,SB;Hatefi,Y
八木隆雄、松野明美、史蒂文B。Vik，* and Youssef Hatefi* 摘要：（1）在氧化磷酸化和ATP驱动的电子从琥珀酸到NAD的上坡转移中，能量驱动反应的速率与底物浓度的双倒数图是一族平行线，在几个固定的亚饱和底物浓度或几个中等浓度的能量产生反应的底物浓度下。如其他地方所示[Hatefi，Y.，Yagi，T.，Phelps，D. C. Wong，S.- Yn Vik，S. B.，& Galante，YM（1982）Proc.Natl. Acad. Sci. USA 79，1756-1760]，部分解偶联降低了V $£ x并增加了能量驱动反应底物的K% £ 9，导致X/Km随着解偶联增加而降低。然而，对产能反应流速的部分限制会降低能量驱动反应底物的V^ l%和K^ 99，导致V n n IK n没有变化。只要速率限制是中等的（例如，< 60%），在此条件下，稳态膜电位（）基本保持不变，这是正确的。在产生能量的反应的高度抑制下，或在低水平解偶联剂存在下的中度抑制下引起部分解偶联，则双倒数图族不再平行，并倾向于向左收敛。在这些条件下，稳态和Vmin/Km也随着抑制的增加而降低。(2)研究了氧化磷酸化、ATP驱动的琥珀酸-NAD电子转移和呼吸驱动的单通道反应中稳态大小与能量驱动反应速率之间的关系
Takao Yagi, Akemi Matsuno-Yagi, Steven B. Vik,* and Youssef Hatefi* abstract:(1) In oxidative phosphorylation and ATP-driven uphill electron transfer from succinate to NAD, double-reciprocal plots of rates vs. substrate concentrations of the en-ergy-driven reactions are a family of parallel linesat several fixed subsaturating concentrations of the substrates or at several moderate concentrations of the inhibitorsof the en-ergy-yielding reactions. Thus, as shown elsewhere [Hatefi, Y., Yagi, T., Phelps, D. C „Wong, S.-Y „Vik, S. B., & Galante, YM (1982) Proc. Natl. Acad. Sci. USA 79, 1756-1760], partial uncoupling decreases the V $£ x and in-creases the K%¡ 9 of the substrates of the energy-driven reac-tions, resulting in a decrease of X/Km as a function of increased uncoupling. However, partial limitation of the flow rates of the energy-yielding reactions decreases both the V^ l% and the K^ 99 of the substrates of the energy-driven reactions, resulting in no change in V „„IK „. This is true as long as the rate limitation is moderate (eg,< 60%), under which con-ditions the steady-state membrane potential () remains essentially unchanged. At high inhibition of the energy-yielding reactions, or at moderate inhibition inthe presence of low levels of an uncoupler to cause partial uncoupling, then the family of double-reciprocal plots is no longer parallel and tends to converge toward the left. Under these conditions, steady-state and VmiJKm also decrease as inhibition is increased.(2) The relationship between the magnitude of steady-state and the rate of the energy-driven reaction was studied in oxidative phosphorylation, ATP-driven electron transfer from succinate to NAD, and respiration-driven uniport