Li S G, Zhang Y, Lin Z H
J Bioenerg Biomembr. 1987 Jun;19(3):273-83. doi: 10.1007/BF00762417.
The membrane sector (F0) of H+-ATPase was prepared by trypsin and urea treatment of F1-F0 and reconstituted with purified F1. The oligomycin sensitivity of the reconstituted F1-F0 complex obtained by treating F1 or F0 with Mg2+ before binding is much higher than that obtained without Mg2+ treatment. The greater change in the intrinsic fluorescence of the reconstituted F1-F0 complex obtained by Mg2+ treatment suggests that conformational changes may occur during the reconstitution. We deduce that Mg2+ binds to membrane lipids, thus decreasing membrane fluidity and changing the physical state of the lipids to provide a suitable microenvironment for conformational changes in F0. The data also suggest that the conformational change in the F0 portion of the F1-F0 complex can be transmitted to the F1 portion, the conformation of which is in turn altered, resulting in the formation of an F1-F0 complex with high oligomycin sensitivity. On the other hand, Mg2+ may act on F1 directly to induce a suitable conformational change which is then transmitted to F0, resulting in the formation of an H+-ATPase with greater sensitivity to oligomycin.
通过用胰蛋白酶和尿素处理F1 - F0来制备H⁺ - ATP酶的膜扇区（F0），并与纯化的F1进行重组。在结合前用Mg²⁺处理F1或F0所获得的重组F1 - F0复合物的寡霉素敏感性远高于未用Mg²⁺处理所获得的。通过Mg²⁺处理获得的重组F1 - F0复合物的固有荧光的更大变化表明在重组过程中可能发生了构象变化。我们推断Mg²⁺与膜脂结合，从而降低膜流动性并改变脂类的物理状态，为F0中的构象变化提供合适的微环境。数据还表明，F1 - F0复合物的F0部分的构象变化可以传递到F1部分，其构象进而改变，导致形成具有高寡霉素敏感性的F1 - F0复合物。另一方面，Mg²⁺可能直接作用于F1以诱导合适的构象变化，然后该变化传递到F0，导致形成对寡霉素更敏感的H⁺ - ATP酶。
