Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, 119991, Moscow, Russia.
Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, 119991, Moscow, Russia; Faculty of Chemistry, Lomonosov Moscow State University, 119991, Moscow, Russia.
Arch Biochem Biophys. 2023 Sep 15;746:109735. doi: 10.1016/j.abb.2023.109735. Epub 2023 Aug 29.
The popular fungicide fluazinam is known to exhibit an unusual cyclic pattern of the protonophoric uncoupling activity in isolated rat liver mitochondria (RLM), with membrane deenergization followed by spontaneous recoupling in the minute scale, which is associated with glutathione conjugation of fluazinam catalyzed by glutathione-S-transferase (GST). Here, we compare the fluazinam effect on RLM with that on rat kidney (RKM) and heart (RHM) mitochondria by monitoring three bioenergetic parameters: oxygen consumption rate, mitochondrial membrane potential and reduction of nucleotides. Only in RLM, the uncoupling activity of fluazinam was transient, i.e. disappeared in a few minutes, whereas in RKM and RHM it was stable in this time scale. We attribute this difference to the increased activity of mitochondrial GST in liver. We report data on the detection of glutathione-fluazinam conjugates by mass-spectrometry, thin layer chromatography and capillary electrophoresis after incubation of fluazinam with RLM but not with RKM, which supports the assumption of the tissue specificity of the conjugation.
已知常用杀真菌剂氟啶胺会在分离的大鼠肝线粒体（RLM）中表现出一种不寻常的质子载体解偶联活性循环模式，即膜去极化，随后在分钟级自发重新偶联，这与谷胱甘肽-S-转移酶（GST）催化的氟啶胺的谷胱甘肽缀合有关。在这里，我们通过监测三个生物能量参数：耗氧量、线粒体膜电位和核苷酸还原来比较氟啶胺对 RLM 与大鼠肾（RKM）和心脏（RHM）线粒体的影响。只有在 RLM 中，氟啶胺的解偶联活性是短暂的，即在几分钟内消失，而在 RKM 和 RHM 中，在这个时间尺度上是稳定的。我们将这种差异归因于肝线粒体 GST 活性的增加。我们报告了在与 RLM 而不是 RKM 孵育氟啶胺后通过质谱、薄层层析和毛细管电泳检测谷胱甘肽-氟啶胺缀合物的数据，这支持了缀合的组织特异性假设。
