Sondermann Markus, George Michael, Fertig Niels, Behrends Jan C
Department of Physiology, Albert-Ludwigs-Universität Freiburg, Hermann-Herder-Str. 7, 79104 Freiburg, Germany.
Biochim Biophys Acta. 2006 Apr;1758(4):545-51. doi: 10.1016/j.bbamem.2006.03.023. Epub 2006 Apr 17.
Microstructured planar substrates have been shown to be suitable for patch clamp recording from both whole cells and isolated patches of membrane, as well as for measurements from planar lipid bilayers. Here, we further explore this technology with respect to high-resolution, low noise single-channel recording. Using solvent-free lipid bilayers from giant unilamellar vesicles obtained by electro-swelling, we recorded channels formed by the peptaibol alamethicin, a well-studied model system for voltage-dependent channels, focusing on the transient dynamics of single-channel formation upon application of a voltage step. With our setup, we were able to distinctly resolve dwell times well below 100 mus and to perform a thorough statistical analysis of alamethicin gating. Our results show good agreement with models that do not rely on the existence of non-conducting preaggregate states. Microstructured apertures in glass substrates appear promising with respect to future experiments on cellular ion channels reconstituted in suspended lipid membranes.
微结构化平面基板已被证明适用于全细胞和分离膜片的膜片钳记录，以及平面脂质双层的测量。在此，我们进一步探索这项技术在高分辨率、低噪声单通道记录方面的应用。使用通过电肿胀获得的巨型单层囊泡形成的无溶剂脂质双层，我们记录了由短杆菌肽A形成的通道，短杆菌肽A是一种研究充分的电压依赖性通道模型系统，重点关注电压阶跃施加后单通道形成的瞬态动力学。通过我们的设置，我们能够清晰地分辨远低于100微秒的驻留时间，并对短杆菌肽A的门控进行全面的统计分析。我们的结果与不依赖于非导电预聚集体状态存在的模型显示出良好的一致性。玻璃基板中的微结构化孔径对于未来在悬浮脂质膜中重构的细胞离子通道实验似乎很有前景。
