Ehrenstein G, Lecar H, Nossal R
J Gen Physiol. 1970 Jan;55(1):119-33. doi: 10.1085/jgp.55.1.119.
When sufficiently small amounts of excitability-inducing material (EIM) are added to a bimolecular lipid membrane, the conductance is limited to a few discrete levels and changes abruptly from one level to another. From our study of these fluctuations, we have concluded that the EIM-doped bilayer contains ion-conducting channels capable of undergoing transitions between two states of different conductance. The difference in current between the "open" and "closed" states is directly proportional to the applied membrane potential, and corresponds to a conductance of about 3 x 10(-10) ohm(-1). The fraction of the total number of channels that is open varies from unity to zero as a function of potential. The voltage-dependent opening and closing of channels explains the negative resistance observed for bimolecular lipid membranes treated with greater amounts of EIM.
当向双分子脂质膜中添加足够少量的兴奋性诱导物质(EIM)时,电导被限制在几个离散水平,并会从一个水平突然跃变到另一个水平。通过对这些波动的研究,我们得出结论,掺杂EIM的双层膜包含能够在两种不同电导状态之间转换的离子导电通道。“开放”和“关闭”状态之间的电流差与施加的膜电位成正比,对应于约3×10⁻¹⁰欧姆⁻¹的电导。开放通道总数的比例随电位从1变化到0。通道的电压依赖性开放和关闭解释了用大量EIM处理的双分子脂质膜中观察到的负电阻现象。