Fuyu Y, Beiqi G, Yuguo H
Biochim Biophys Acta. 1983 Jul 29;724(1):104-10. doi: 10.1016/0005-2728(83)90030-0.
During reconstitution of pig heart mitochondrial H+-ATPase in soybean phospholipid liposomes by the cholate dialysis method, Mg2+ greatly enhances 32Pi-ATP exchange activity, ATPase activity and the sensitivity to oligomycin of the reconstituted enzyme complex. The effect of Mg2+ on the fluidity of the reconstituted proteoliposomes was measured by means of a fluoursecent probe. 1-anilinonaphthalene ¿e-8-sulfonate, and spin-label probes, 5-nitroxide stearate, 12-nitroxide stearate and 16-nitroxide stearate. A difference in fluidity seems to be localized near the polar faces of the lipid bilayers of the reconstituted proteolipsomes. Fluidity was less in the presence of Mg2+ than it is absence. The conformations of the Mg2+-containing proteoliposomes was higher. We postulate that Mg2+ may play a role in altering the fluidity of the proteoliposomes, which would favor the formation of a conformation of the reconstituted H+-ATPase with higher activity.
在用胆酸盐透析法将猪心脏线粒体H⁺-ATP酶重组到大豆磷脂脂质体的过程中，Mg²⁺极大地增强了重组酶复合物的³²Pi-ATP交换活性、ATP酶活性以及对寡霉素的敏感性。通过荧光探针1-苯胺基萘-6-磺酸以及自旋标记探针5-硝基硬脂酸盐、12-硝基硬脂酸盐和16-硝基硬脂酸盐来测定Mg²⁺对重组蛋白脂质体流动性的影响。流动性的差异似乎定位在重组蛋白脂质体脂质双层的极性面附近。存在Mg²⁺时的流动性比不存在时要小。含Mg²⁺的蛋白脂质体的构象更高。我们推测Mg²⁺可能在改变蛋白脂质体的流动性方面发挥作用，这将有利于形成具有更高活性的重组H⁺-ATP酶构象。
