Todorov G, Sokerov S, Stoylov S P
Biophys J. 1982 Oct;40(1):1-5. doi: 10.1016/S0006-3495(82)84451-2.
An investigation of the scattered light (lambda = 632.8 nm) from purple membrane suspensions with different concentrations subjected to external AC and DC electric fields has been carried out. The electric pulses used were in the field strength range 0-3.2 X 10(4) Vm-1 and the frequency range 10 Hz-1 MHz, the pulse duration being less than or equal to 0.5 s. A concentration dependence of the relative changes in the scattered light intensity was obtained, the effect being positive on orienting the suspensions by an AC field at 1 and 10 kHz, and negative in the case of a DC field. The negative effects in the diluted samples decrease and turn positive as the strength of the field increases. The positive effects show the existence of an interfacial polarizability along the plane of the membrane, and the negative ones suggest the presence of a permanent dipole moment (p), perpendicular to the plane of the membrane. The values of gamma (induced polarizability) and p were found to be on the order of 10(-28)-10(-29) Fm2 and 10(-24) Cm, respectively. An explanation in terms of membrane aggregation for the observed dependence on concentration is given.
对不同浓度的紫膜悬浮液在外部交流电场和直流电场作用下散射光（波长λ = 632.8 nm）进行了研究。所使用的电脉冲场强范围为0 - 3.2×10⁴ Vm⁻¹，频率范围为10 Hz - 1 MHz，脉冲持续时间小于或等于0.5 s。得到了散射光强度相对变化的浓度依赖性，在1 kHz和10 kHz的交流电场作用下，该效应对于使悬浮液定向是正的，而在直流电场情况下是负的。稀释样品中的负面影响随着场强增加而减小并变为正效应。正效应表明沿膜平面存在界面极化率，而负效应表明存在垂直于膜平面的永久偶极矩（p）。发现γ（感应极化率）和p的值分别约为10⁻²⁸ - 10⁻²⁹ Fm²和10⁻²⁴ Cm。给出了关于所观察到的浓度依赖性的膜聚集方面的解释。
