Vagaries of artificial bilayers and gating modes of the SCl channel from the sarcoplasmic reticulum of skeletal muscle |
| |
Authors: | Joseph I Kourie |
| |
Institution: | Muscle Research Group, John Curtin School of Medical Research, ANU, PO Box 334, Canberra City, ACT, 2601, Australia |
| |
Abstract: | The elucidation of the structure-function relation of reconstituted ion channel proteins into artificial planar bilayers is expected to be greatly influenced by the physical properties of these bilayers. The dependence of the gating mode of a voltage- and calcium-dependent small chloride channel (SCl channel) on the bilayer properties, as deduced from the specific bilayer capacitance, Cb, was investigated. In bilayers having a Cb value of 0.42 μF/cm2 the SCl channel was in the “burst mode”. At a Cb value of 0.28 μF/cm2 the “burst mode” gave way to a “flickering mode”. At Cb values between 0.24 and 0.28 μF/cm2 channel bursts were often infrequent and brief. No ion channel activities were observed at Cb values lower than 0.24 μF/cm2. These results suggest that changes in bilayer thickness, mediated via n-decane, contribute to changes in channel gating mode, i.e. “gear shift”. Standardizing Cb and its time-independence are important in comparative and detailed investigations of ion channel characteristics. |
| |
Keywords: | Bilayer vagaries Chloride channel Sarcoplasmic reticulum Skeletal muscle Specific bilayer capacitance |
本文献已被 ScienceDirect 等数据库收录! |
|