Buttgereit F, Brand M D
Department of Biochemistry, University of Cambridge, U.K.
Biochem J. 1995 Nov 15;312 ( Pt 1)(Pt 1):163-7. doi: 10.1042/bj3120163.
The rates of different ATP-consuming reactions were measured in concanavalin A-stimulated thymocytes, a model system in which more than 80% of the ATP consumption can be accounted for. There was a clear hierarchy of the responses of different energy-consuming reactions to changes in energy supply: pathways of macromolecule biosynthesis (protein synthesis and RNA/DNA synthesis) were most sensitive to energy supply, followed by sodium cycling and then calcium cycling across the plasma membrane. Mitochondrial proton leak was the least sensitive to energy supply. Control analysis was used to quantify the relative control over ATP production exerted by the individual groups of ATP-consuming reactions. Control was widely shared; no block of reactions had more than one-third of the control. A fuller control analysis showed that there appeared to be a hierarchy of control over the flux through ATP: protein synthesis > RNA/DNA synthesis and substrate oxidation > Na+ cycling and Ca2+ cycling > other ATP consumers and mitochondrial proton leak. Control analysis also indicated that there was significant control over the rates of individual ATP consumers by energy supply. Each ATP consumer had strong control over its own rate but very little control over the rates of the other ATP consumers.
在伴刀豆球蛋白A刺激的胸腺细胞中测量了不同ATP消耗反应的速率，该模型系统中80%以上的ATP消耗都可得到解释。不同耗能反应对能量供应变化的反应存在明显的层次结构：大分子生物合成途径（蛋白质合成以及RNA/DNA合成）对能量供应最为敏感，其次是钠循环，然后是跨质膜的钙循环。线粒体质子泄漏对能量供应最不敏感。采用控制分析来量化由各个ATP消耗反应组对ATP产生施加的相对控制。控制作用广泛分布；没有任何一组反应的控制作用超过三分之一。更全面的控制分析表明，似乎对通过ATP的通量存在控制层次结构：蛋白质合成>RNA/DNA合成和底物氧化>Na+循环和Ca2+循环>其他ATP消耗者和线粒体质子泄漏。控制分析还表明，能量供应对各个ATP消耗者的速率有显著控制作用。每个ATP消耗者对自身速率有很强的控制作用，但对其他ATP消耗者的速率几乎没有控制作用。
