Battino M, Bertoli E, Formiggini G, Sassi S, Gorini A, Villa R F, Lenaz G
Istituto di Biochimica, Università di Ancona, Italy.
J Bioenerg Biomembr. 1991 Apr;23(2):345-63. doi: 10.1007/BF00762227.
Studies on brain mitochondria are complicated by the regional, cellular, and subcellular heterogeneity of the central nervous system. This study was performed using synaptic and nonsynaptic mitochondria obtained from cortex, hippocampus, and striatum of male Sprague-Dawley rats (3 months old). Ubiquinone content, detected by HPLC analysis, was about 1.5 nmol/mg protein with an approximate CoQ9/CoQ10 molecular ratio of 2:1. The activities of several respiratory chain complexes were also studied (succinate-cyt. c reductase, NADH-cyt. c reductase, succinate-DCIP, ubiquinol2-cyt. c reductase, and cytochrome oxidase), and generally found to be higher in mitochondria from cortex than from other regions. Study of the activities of some of these enzymes vs. 1/T (Arrhenius plots) showed a straight line with an activation energy between 7 and 10 kcal/mol in all the three areas considered. Only CoQ2H2-cyt. c reductase activity revealed a biphasic temperature dependence. Also anisotropy (as fluorescence polarization) of the hydrophobic probe DPH showed a deviation from linearity; the break points for both enzymatic activity and anisotropy were found at about 23-24 degrees C.
对脑线粒体的研究因中枢神经系统的区域、细胞和亚细胞异质性而变得复杂。本研究使用从3月龄雄性Sprague-Dawley大鼠的皮质、海马和纹状体中获得的突触和非突触线粒体进行。通过HPLC分析检测到的泛醌含量约为1.5 nmol/mg蛋白质，CoQ9/CoQ10分子比约为2:1。还研究了几种呼吸链复合物的活性（琥珀酸-细胞色素c还原酶、NADH-细胞色素c还原酶、琥珀酸-DCIP、泛醇-细胞色素c还原酶和细胞色素氧化酶），通常发现皮质线粒体中的活性高于其他区域。对其中一些酶的活性与1/T（阿累尼乌斯图）的研究表明，在所考虑的所有三个区域中，活化能在7至10 kcal/mol之间时呈直线。只有CoQ2H2-细胞色素c还原酶活性显示出双相温度依赖性。疏水探针DPH的各向异性（作为荧光偏振）也显示出与线性的偏差；酶活性和各向异性的断点均出现在约23-24摄氏度处。
