Kagawa Y, Ohno K, Yoshida M, Takeuchi Y, Sone N
Fed Proc. 1977 May;36(6):1815-8.
Stable membrane proteins and lipids are convenient to study biomembranes. Two stable proton translocating proteins were purified and reconstituted into vesicles capable of proton translocation. One was a thermostable ATPase (TF0-F1) of thermophilic bacterium PS3 and the other was rhodopsin of Halobacterium halobium. TF0-F1 was composed of a proton pump moiety (TF1) and a proton channel moiety (TF0). TF1 was the first membrane ATPase which was crystallized and reconstituted from its five polypeptides. Like TF0 and TF1, the rhodopsin in purple membrane was highly stable against dissociating agents, acids and alkali. Phospholipids of these biomembranes were also stable and contained no unsaturated fatty acyl groups. The molecular species of the phospholipids of PS3 were determined by mass chromatography. Measurements were made of the difference in electrochemical potential of protons (deltamicronH+) across the membrane of the reconstituted vesicles. The deltamicronH+ attained was 312 mV in TF0-F1 vesciles and was 230 mV in the rhodopsin vesicles. To conclude that electron transport components are not necessary for ATP synthesis in energy yielding biomembranes, two experiments were performed: The ATP synthesis was observed i) on acid-base treatment of TF0-F1 vesicles, and ii) on illumination of the rhodopsin-TF0-F1 vesicles.
稳定的膜蛋白和脂质便于研究生物膜。两种稳定的质子转运蛋白被纯化并重新组装到能够进行质子转运的囊泡中。一种是嗜热细菌PS3的耐热ATP酶（TF0 - F1），另一种是嗜盐菌的视紫红质。TF0 - F1由质子泵部分（TF1）和质子通道部分（TF0）组成。TF1是第一个从其五条多肽结晶并重新组装的膜ATP酶。与TF0和TF1一样，紫膜中的视紫红质对解离剂、酸和碱具有高度稳定性。这些生物膜的磷脂也很稳定，不含不饱和脂肪酰基。通过质谱色谱法测定了PS3磷脂的分子种类。测量了重组囊泡膜两侧质子的电化学势差（deltamicronH +）。在TF0 - F1囊泡中达到的deltamicronH +为312 mV，在视紫红质囊泡中为230 mV。为了得出在产能生物膜中ATP合成不需要电子传递成分的结论，进行了两个实验：i）对TF0 - F1囊泡进行酸碱处理时观察到ATP合成，ii）对视紫红质 - TF0 - F1囊泡进行光照时观察到ATP合成。
