Abstract
The effects of cysteine-modifying reagents on the gating of rat cloned Kv1.4 channels expressed in HEK-293 cells were examined using the whole-cell patch-clamp technique. Cells transfected with Kv1.4 expressed a rapidly inactivating K+ current with a midpoint of activation of −31 mV and a slope factor of 5 mV measured with tail current protocols in 35 mM Rb+ external solutions. The cysteine-specific oxidizing agents 2,2′-dithiobis-5-nitropyridine (DTBNP, 50 μM) and chloramine-T (CL-T, 500 μM) removed inactivation of Kv1.4. These effects were reversed by the reducing agent dithiothreitol (DTT, 10 mM). In addition, DTBNP and CL-T also slowed Kv1.4 deactivation and increased the voltage sensitivity of deactivation. The action of cysteine-modifying reagents on Kv1.4 suggests that redox state affects channel gating, with oxidation tending to stabilize the open state of the channel, both by removing inactivation and slowing deactivation.
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Stephens, G.J., Owen, D.G. & Robertson, B. Cysteine-modifying reagents alter the gating of the rat cloned potassium channel Kv1.4. Pflugers Arch. 431, 435–442 (1996). https://doi.org/10.1007/BF02207283
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DOI: https://doi.org/10.1007/BF02207283