线粒体内底物浓度作为控制新陈代谢的一个因素。阴离子间竞争的作用。

Intramitochondrial substrate concentration as a factor controlling metabolism. The role of interanion competition.

Harris E J, Manger J R

Biochem J. 1968 Sep;109(2):239-46. doi: 10.1042/bj1090239.

Abstract

The concentration-dependence of the intramitochondrial accumulation of l-malate and succinate was measured and expressed in the form of adsorption isotherms. The accumulation, however, may arise because of an internal positive potential. 2. The competition for accumulation offered by some other anions, including phosphate, was measured and is expressed conventionally by additional terms in the adsorption equation. 3. The interactions between anions were also studied when one was acting as oxidized substrate. 4. In some examples there is a parallel between the effects of an added anion on both accumulation and oxidation; in other cases chemical participation of the added substance in metabolism is presumed to remove the correlation. 5. It is suggested that by combining kinetic data on penetration with stoicheiometric data on accumulation and specific reaction rates it may be possible to account for the rates of respiration obtained with intact mitochondria. 6. It is possible to show that there is a certain phosphate/substrate ratio for maximum phosphorylation rate with some substrates. This is to be expected when phosphate and substrate compete for accumulation.

摘要

测定了苹果酸和琥珀酸在线粒体内积累的浓度依赖性，并以吸附等温线的形式表示。然而，这种积累可能是由于内部正电位引起的。2. 测量了包括磷酸盐在内的其他一些阴离子对积累的竞争作用，并通过吸附方程中的附加项按常规方式表示。3. 还研究了一种阴离子作为氧化底物时阴离子之间的相互作用。4. 在一些例子中，添加的阴离子对积累和氧化的影响存在平行关系；在其他情况下，推测添加物质在代谢中的化学参与消除了这种相关性。5. 有人提出，通过将渗透的动力学数据与积累的化学计量数据和特定反应速率相结合，有可能解释完整线粒体的呼吸速率。6. 可以表明，对于某些底物，存在一个使磷酸化速率最大化的特定磷酸盐/底物比率。当磷酸盐和底物竞争积累时，这是可以预料的。