Seta P, Ormos P, d'Epenoux B, Gavach C
Biochim Biophys Acta. 1980 Jun 10;591(1):37-52. doi: 10.1016/0005-2728(80)90218-2.
The photo response of bacteriorhodopsin adsorbed on a bimolecular lipid membrane has been investigated using short-circuit current measurements. The results revealed a biphasic current vs. time curve for the photocurrent at pH values of approx. 7. This phenomenon could be modified by altering either the value of the external applied electrical field or the proton concentration differences. The observed effects of the external applied voltage, pH gradient and lipophilic proton carriers enabled us to conclude that the bacteriorhodopsin can be adsorbed in two different states, which give rise to a pumping effect and a flux of protons in opposite directions. A theoretical analysis of the photocycle in relation to the electrical field which acts on the proton uptake and release is proposed. The main effect of this field is to diminish the pumping rate due to the proton motive force resulting from the creation of space-charge in the vicinity of purple membrane fragments.
利用短路电流测量法，研究了吸附在双分子脂膜上的细菌视紫红质的光响应。结果显示，在pH值约为7时，光电流的电流-时间曲线呈双相。通过改变外部施加电场的值或质子浓度差，可以改变这种现象。外部施加电压、pH梯度和亲脂性质子载体的观察效应使我们得出结论，细菌视紫红质可以以两种不同状态吸附，这会产生相反方向的泵送效应和质子通量。提出了与作用于质子吸收和释放的电场相关的光循环理论分析。该电场的主要作用是由于紫色膜片段附近空间电荷的产生导致质子动力降低泵送速率。
