Miller C
Biophys J. 1982 Jun;38(3):227-30. doi: 10.1016/S0006-3495(82)84552-9.
Streaming potentials arising across a K+-selective channel from fragmented sarcoplasmic reticulum were measured by incorporating the channel into planar bilayer membranes and imposing osmotic gradients across the membranes by addition of sorbitol or urea to only one side. Single-channel zero-current potentials were determined, and dilution artifacts were corrected for by addition of valinomycin to the bilayer. The streaming potentials were found to be unusually small, 1.1 mV per osmolal. The potentials were linearly related to the osmotic gradient across the bilayer, and were identical for sorbitol and urea. The results imply that the channel cannot be envisioned as a long tube, like gramicidin, but rather as a short constriction of less than 10 A in length opening out into wider mouths on either side of the membrane.
通过将钾离子选择性通道整合到平面双层膜中，并仅在一侧添加山梨醇或尿素以在膜上施加渗透梯度，来测量破碎肌浆网中钾离子选择性通道产生的流动电位。测定了单通道零电流电位，并通过向双层膜中添加缬氨霉素来校正稀释假象。发现流动电位异常小，每渗透压为1.1毫伏。这些电位与双层膜上的渗透梯度呈线性关系，并且山梨醇和尿素的电位相同。结果表明，该通道不能像短杆菌肽那样被设想为长管，而应被视为长度小于10埃的短缩窄通道，在膜的两侧开口为更宽的口。
