ENERGETIC ASPECTS OF THE MITOCHONDRIAL OXIDATION OF SUCCINATE
ENERGETIC ASPECTS OF THE MITOCHONDRIAL OXIDATION OF SUCCINATE
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DOI：
10.1038/188552a0
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发表时间：
1960-01-01
期刊：
影响因子：
64.8
通讯作者：
KLINGENBERG, M
中科院分区：
文献类型：
--
作者：
AZZONE, GF;ERNSTER, L;KLINGENBERG, M
Fig. 1.同时记录呼吸（a）和吡啶核苷酸吸收（B）。大鼠肝线粒体，3-8 nmgm。保护/ ml.在0-13 mM氯化钾中。0-008 M氯酸镁，0-02 M三乙醇胺盐酸盐，pH 7-5。As，砷酸盐; J）ic，双香豆素; Suc，琥珀酸盐。由于双香豆素吸收的补偿，在加入双香豆素时出现不连续的吸收迹线。这些数字表示吡啶核苷酸分析的提取时间，其结果在表i中给出。在高能磷酸盐耗尽的线粒体中琥珀酸的氧化伴随着线粒体吡啶核苷酸的还原，以及该过程是否类似于三磷酸腺苷诱导的呼吸刺激，可以在解偶联剂存在下发生。这里给出的结果清楚地表明情况就是这样。还原吡啶核苷酸的定性和定量估计也进行了，而且，此外，数据上的线粒体黄素和细胞色素B的氧化还原状态获得。这些研究结果的功能连接的琥珀酸脱氢酶的终端电子传递系统的机制的一些影响将被考虑。实验需要使用配备振动氧电极的双光束分光光度计，同时测量氧摄取量和适当波长处的光谱吸收差异。如Klingenberg等人先前所述制备两次洗涤的大鼠肝线粒体。".孵育培养基含有0-13 M氯化钾、0-02 M三乙醇胺缓冲液（pH 7-5）和0008 M氯化镁。测量在25 ℃下进行.在0-5和1cm的石英比色皿中。还原和氧化的吡啶核苷酸的提取和酶测定基本上如前所述进行 *。一个典型的实验如图1所示。在该实验中，线粒体在砷酸盐和双香豆素存在下预孵育3分钟。内源呼吸在预孵育开始时相当高，但在约2分钟后下降至几乎为零。
Fig. 1. Simultaneous recording of respiration (a) and pyridine nucleotide absorption (b). Rat liver mitochondria, 3-8 nmgm. prot./ml. in 0-13 m M potassium chloride. 0-008 M Magnesium chlorate, 0-02 M triethanolamine hydrochloride, pH 7-5. As, arsenate; J) ic, dicoumarol; Succ, succinate. Discontinuous absorption trace at the addition of dicournarol because of compensation for the dicoumarol absorption. The numbers indicate the monents of extraction for pyridine nucleotide analysis, the results of which are given in Table i oxidation of succinate in mitochondria depleted of high-energy phosphate is accompanied by a reduction of the mitochondrial pyridine nucleotide, and whether this process, similarly to the adenosine triphosphateinduced respiratory stimulation, can take place in the presence of uncouplers. The results presented here clearly indicate that this is the case. Qualitative and cuantitative estimates of the reduced pyridine nucleotides were also carried out, and, in addition, data were obtained on the oxido-reduction states of the mitochondrial flavin and cytochrome b. Some implications of these findings for the mechanism of the functional link of succinic dehydrogenase to the terminal electron transport system will be considered. The experiments entailed a simultaneous measure-ment of the oxygen uptake and of the difference in spectral absorption at suitable wave-lengths, using a double-beam spectrophotometer equipped with a vibrating oxygen electrodeº. Twice-washed rat liver mitochondria were prepared as previously described by Klingenberg et al.". The incubation medium contained 0-13 M potassium chloride, 0-02 M triethanolamine buffer, pH 7-5, and 0008 M mag-nesium chloride. The measurements were carried out at 25 C. in quartz cuvettes of 0-5 and 1 cm. light-path. Extractions and enzymic determinations of the reduced and oxidized pyridine nucleotides were performed essentially as described previously*. A typical experiment is shown in Fig. l. In this experiment, the mitochondria were pre-incubated for 3 min. in the presence of arsenate and dicoumarol. The endogenous respiration was rather high at the onset of the pre-incubation, but declined to almost zero after about 2 min. Subsequent addition of