Calcium regulation of oxidative phosphorylation in rat skeletal muscle mitochondria
Calcium regulation of oxidative phosphorylation in rat skeletal muscle mitochondria
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DOI：
10.1016/s0005-2728(00)00054-2
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发表时间：
2000-02-24
影响因子：
4.3
通讯作者：
Brand, MD
中科院分区：
文献类型：
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作者：
Kavanagh, NI;Ainscow, EK;Brand, MD
使用自上而下的弹性和调节分析来分析大鼠骨骼肌线粒体中钙的生理水平对氧化磷酸化的激活。氧化磷酸化在概念上分为三个子系统（底物氧化、质子泄漏和磷酸化），通过膜电位或质子动力连接。钙直接激活磷酸化子系统和（使用亚饱和2-酮戊二酸）底物氧化子系统，但对质子泄漏动力学没有影响。使用对照和调节分析来量化在两种生理浓度的游离钙下线粒体对 2-酮戊二酸的呼吸反应。部分积分响应系数表明，钙对3态氧消耗的影响中，直接刺激底物氧化贡献了86%，而磷酸化反应的直接激活则导致了磷酸化通量增加的37%。钙直接激活磷酸化比底物氧化更强烈（78% 比 45%），以在通量大幅增加期间实现线粒体膜电位的稳态。 (C) 2000 Elsevier Science B.V. 保留所有权利。
Activation of oxidative phosphorylation by physiological levels of calcium in mitochondria from rat skeletal muscle was analysed using top-down elasticity and regulation analysis. Oxidative phosphorylation was conceptually divided into three subsystems (substrate oxidation, proton leak and phosphorylation) connected by the membrane potential or the protonmotive force. Calcium directly activated the phosphorylation subsystem and (with sub-saturating 2-oxoglutarate) the substrate oxidation subsystem but had no effect on the proton leak kinetics. The response of mitochondria respiring on 2-oxoglutarate at two physiological concentrations of free calcium was quantified using control and regulation analysis. The partial integrated response coefficients showed that direct stimulation of substrate oxidation contributed 86% of the effect of calcium on state 3 oxygen consumption, and direct activation of the phosphorylation reactions caused 37% of the increase in phosphorylation flux. Calcium directly activated phosphorylation more strongly than substrate oxidation (78% compared to 45%) to achieve homeostasis of mitochondrial membrane potential during large increases in flux. (C) 2000 Elsevier Science B.V. All rights reserved.