Zanotti F, Guerrieri F, Capozza G, Fiermonte M, Berden J, Papa S
Institute of Medical Biochemistry and Chemistry, Consiglio Nazionale delle Ricerche, University of Bari, Italy.
Eur J Biochem. 1992 Aug 15;208(1):9-16. doi: 10.1111/j.1432-1033.1992.tb17153.x.
A study is presented on the role of F0 and F1 subunits in oligomycin-sensitive H+ conduction and energy transfer reactions of bovine heart mitochondrial F0F1 H(+)-ATP synthase. Mild treatment with azodicarboxylic acid bis(dimethylamide) (diamide) enhanced oligomycin-sensitive H+ conduction in submitochondrial particles containing F1 attached to F0. This effect was associated with stimulation of the ATPase activity, with no effect on its inhibition by oligomycin, and depression of the 32Pi-ATP exchange. The stimulatory effect of diamide on H+ conduction decreased in particles from which F1 subunits were partially removed by urea. The stimulatory effect exerted by diamide in the submitochondrial particles with F1 attached to F0 was directly correlated with a decrease of the original electrophoretic bands of a subunit of F0 (F0I-PVP protein) and the gamma subunit of F1, with corresponding formation of their cross-linking product. In F0 liposomes, devoid of gamma subunit, diamide failed to stimulate H+ conduction and to cause disappearance of F0I-PVP protein, unless purified gamma subunit was added back. The addition to F0 liposomes of gamma subunit, but not that of alpha and beta subunits, caused per se inhibition of H+ conduction. It is concluded that F0I-PVP and gamma subunits are directly involved in the gate of the F0F1 H(+)-ATP synthase. Data are also presented indicating contribution to the gate of oligomycin-sensitivity conferral protein and of another protein subunit of F0, F6.
本文介绍了一项关于F0和F1亚基在牛心线粒体F0F1 H(+)-ATP合酶的寡霉素敏感H+传导和能量转移反应中的作用的研究。用偶氮二甲酸双（二甲酰胺）（二酰胺）进行温和处理可增强含有与F0相连的F1的亚线粒体颗粒中的寡霉素敏感H+传导。这种效应与ATP酶活性的刺激有关，对寡霉素对其的抑制没有影响，并且降低了32Pi-ATP交换。二酰胺对H+传导的刺激作用在通过尿素部分去除F1亚基的颗粒中降低。二酰胺在含有与F0相连的F1的亚线粒体颗粒中施加的刺激作用与F0的一个亚基（F0I-PVP蛋白）和F1的γ亚基的原始电泳带的减少直接相关，同时相应地形成它们的交联产物。在不含γ亚基的F0脂质体中，二酰胺未能刺激H+传导并导致F0I-PVP蛋白消失，除非重新添加纯化的γ亚基。向F0脂质体中添加γ亚基而非α和β亚基本身会导致H+传导受到抑制。得出的结论是，F0I-PVP和γ亚基直接参与F0F1 H(+)-ATP合酶的门控。还提供了数据，表明寡霉素敏感性赋予蛋白和F0的另一个蛋白亚基F6对门控有贡献。
