Sachs F, Qin F
State University of New York, Buffalo 14124.
Biophys J. 1993 Sep;65(3):1101-7. doi: 10.1016/S0006-3495(93)81149-4.
Gigaohm seals made between patch pipettes and hydrophobic substrates have a finite conductance which are cation-selective and capable of producing quantized gating indistinguishable from the gating of biological ion channels. The selectivity sequence and streaming potentials of these seals suggests the existence of a pore of similar dimensions to the nicotinic acetylcholine channel. The ionic selectivity of these seals appears similar to the seal selectivity observed with membrane patches (Fischmeister, R., R. K. Ayer, and R. L. DeHann. 1986. Pfluegers Arch. 406:73-82) and the possibility of discrete gating within the seal region suggests caution when interpreting patch clamp data from unfamiliar preparations. The data suggests that the permeation pathway is the narrow space between the hydrophobic substrate and the pipette. Since this space has one hydrophobic wall, a hydrophilic channel lining may not be essential for channel permeation and gating.
膜片吸管与疏水基质之间形成的千兆欧密封具有有限的电导，这些密封具有阳离子选择性，并且能够产生与生物离子通道门控无法区分的量化门控。这些密封的选择性序列和流动电位表明存在一个与烟碱型乙酰胆碱通道尺寸相似的孔。这些密封的离子选择性似乎与在膜片上观察到的密封选择性相似（菲施迈斯特，R.，R.K.艾耶尔，和R.L.德汉。1986年。《普弗吕格尔氏文献》406:73 - 82），并且密封区域内离散门控的可能性表明，在解释来自不熟悉制剂的膜片钳数据时要谨慎。数据表明，渗透途径是疏水基质和吸管之间的狭窄空间。由于这个空间有一个疏水壁，亲水性通道内衬对于通道渗透和门控可能不是必需的。
