Nesci Salvatore, Trombetti Fabiana, Ventrella Vittoria, Pirini Maurizio, Pagliarani Alessandra
Department of Veterinary Medical Sciences (DIMEVET), University of Bologna, via Tolara di Sopra 50, 40064, Ozzano dell'Emilia, BO, Italy.
Department of Veterinary Medical Sciences (DIMEVET), University of Bologna, via Tolara di Sopra 50, 40064, Ozzano dell'Emilia, BO, Italy.
Biochimie. 2017 Sep;140:73-81. doi: 10.1016/j.biochi.2017.06.013. Epub 2017 Jun 23.
The mitochondrial F-ATPase can be activated either by the classical cofactor Mg or, with lower efficiency, by Ca. The latter may play a role when calcium concentration rises in mitochondria, a condition associated with cascade events leading to cell death. Common and distinctive features of these differently activated mitochondrial ATPases were pointed out in swine heart mitochondria. When Ca replaces the natural cofactor Mg, the enzyme responsiveness to the transmembrane electrochemical gradient and to the classical F-ATPase inhibitors DCCD and oligomycin as well as the oligomycin sensitivity loss by thiol oxidation, are maintained. Consistently, the two mitochondrial ATPases apparently share the FF complex basic structure and mechanism. Peculiar cation-dependent properties, which may affect the F catalytic mechanism and/or the F proton binding site features, may be linked to a different physiological role of the mitochondrial Ca-activated F-ATPase with respect to the Mg-activated F-ATPase.
线粒体F-ATP酶可被经典辅因子Mg激活，也可被Ca激活，但效率较低。当线粒体中钙浓度升高时，后者可能发挥作用，这种情况与导致细胞死亡的级联事件有关。在猪心脏线粒体中指出了这些不同激活方式的线粒体ATP酶的共同特征和独特特征。当Ca取代天然辅因子Mg时，酶对跨膜电化学梯度、经典F-ATP酶抑制剂二环己基碳二亚胺（DCCD）和寡霉素的反应性，以及硫醇氧化导致的寡霉素敏感性丧失，均得以维持。一致地，这两种线粒体ATP酶显然共享F₀F₁复合物的基本结构和机制。可能影响F₁催化机制和/或F₀质子结合位点特征的特殊阳离子依赖性特性，可能与线粒体钙激活F-ATP酶相对于镁激活F-ATP酶的不同生理作用有关。
