Factors determining the relative contribution of the adenine-nucleotide translocator and the ADP-regenerating system to the control of oxidative phosphorylation in isolated rat-liver mitochondria.
Factors determining the relative contribution of the adenine-nucleotide translocator and the ADP-regenerating system to the control of oxidative phosphorylation in isolated rat-liver mitochondria.
复制标题
决定腺嘌呤核苷酸易位子和 ADP 再生系统对离体大鼠肝线粒体氧化磷酸化控制的相对贡献的因素。
DOI：
10.1111/j.1432-1033.1984.tb08303.x
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发表时间：
1984
期刊：
影响因子：
--
通讯作者：
J. Tager
中科院分区：
文献类型：
--
作者：
R. Wanders;A. Groen;C. V. Roermund;J. Tager
在用琥珀酸呼吸的离体大鼠肝脏线粒体中研究了腺嘌呤核苷酸易位子和 ADP 再生系统对氧化磷酸化的控制。在中等呼吸速率下，使用肌酸/肌酸激酶时，腺嘌呤核苷酸易位子对呼吸的通量控制系数（控制强度）比使用葡萄糖/己糖激酶作为ADP再生系统高得多。相反，在相同呼吸速率下，肌酸激酶的通量控制系数远低于己糖激酶。在葡萄糖/己糖激酶或肌酸/肌酸激酶存在的情况下，向进行呼吸的线粒体添加少量羧基苍术苷，呼吸速率突然降低，然后再次增加至新的稳态，肌酸/肌酸激酶的呼吸速率低于葡萄糖/己糖激酶的呼吸速率。在新的稳定状态下，葡萄糖/己糖激酶的线粒体外 ATP/ADP 比率低于肌酸/肌酸激酶。在相同呼吸速率下，肌酸激酶对线粒体外ATP/ADP比值的弹性系数远高于己糖激酶。连通性定理 [Kacser, H. 和 Burns, J.A. (1973) in Rate Control of Biological Processes (Davies, D.D., ed.) pp. 65-104, Cambridge University Press, London] 将两种相邻酶的通量控制系数与其对共同中间体的弹性系数联系起来，解释了腺嘌呤核苷酸易位器与两个 ADP 再生系统的通量控制系数的差异。使用 R. Heinrich 和 T.A. 开发的原理Rapoport [BioSystems 7, 130-136 (1975)]，腺嘌呤核苷酸转位子和己糖激酶对磷酸化的通量控制系数也根据这些酶对线粒体外 ATP/ADP 比率的弹性系数以及这些酶对线粒体外 ATP/ADP 比率施加的控制来计算。计算值比直接测量值低约 30%。使用 Kacser 和 Burns 的连接定理（上文引用）或 Westerhoff 开发的新连接定理（本期刊的下一篇论文）确定腺嘌呤核苷酸易位子对线粒体外 ATP/ADP 比率的弹性系数。使用不同的计算方法获得了良好的一致性。（摘要截断为 400 字）
The control exerted by the adenine nucleotide translocator and the ADP-regenerating system on oxidative phosphorylation was studied in isolated rat-liver mitochondria respiring with succinate. At intermediate rates of respiration the flux control coefficient (control strength) of the adenine nucleotide translocator on respiration was much higher with creatine/creatine kinase than with glucose/hexokinase as the ADP-regenerating system. In contrast, at the same rate of respiration the flux control coefficient of creatine kinase was much lower than that of hexokinase. On addition of a small amount of carboxyatractyloside to mitochondria respiring in the presence of glucose/hexokinase or creatine/creatine kinase, the rate of respiration decreased abruptly and then increased again to a new steady state which was lower with creatine/creatine kinase than with glucose/hexokinase. In the new steady state, the extramitochondrial ATP/ADP ratio was lower with glucose/hexokinase than with creatine/creatine kinase. At the same rate of respiration, the elasticity coefficient of creatine kinase towards the extramitochondrial ATP/ADP ratio was much higher than that of hexokinase. The connectivity theorem [Kacser, H. and Burns, J.A. (1973) in Rate Control of Biological Processes (Davies, D.D., ed.) pp. 65-104, Cambridge University Press, London] which relates the flux control coefficients of two adjacent enzymes to their elasticity coefficients towards the common intermediate, provides an explanation for the difference in flux control coefficient of the adenine nucleotide translocator with the two ADP-regenerating systems. Using principles developed by R. Heinrich and T.A. Rapoport [BioSystems 7, 130-136 (1975)], the flux control coefficients of the adenine nucleotide translocator and hexokinase on phosphorylation were also calculated from the elasticity coefficients of these enzymes towards the extramitochondrial ATP/ADP ratio and the controls exerted by these enzymes on the extramitochondrial ATP/ADP ratio. The calculated values were approximately 30% lower than the values measured directly. The elasticity coefficient of the adenine nucleotide translocator towards the extramitochondrial ATP/ADP ratio was determined, using either the connectivity theorem of Kacser and Burns (loc. cit.) or a new connectivity theorem developed by Westerhoff (following paper in this journal). Good agreement was obtained using the different methods of calculation.(ABSTRACT TRUNCATED AT 400 WORDS)