Cysteine-modifying reagents alter the gating of the rat cloned potassium channel Kv1.4

Pflugers Arch. 1996 Jan;431(3):435-42. doi: 10.1007/BF02207283.


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 mid-point 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 microM) and chloramine-T (CL-T, 500 microM) removed inactivation of Kv1.4. These effects were reversed by the reducing agent dithiothreitol (DTT, 10mM). 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.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Clone Cells
  • Cysteine / pharmacology*
  • Electrophysiology
  • Extracellular Space / chemistry
  • Ion Channel Gating / drug effects
  • Potassium Channels / physiology*
  • Pyridines / pharmacology
  • Rats
  • Rubidium / pharmacology
  • Sulfhydryl Reagents / pharmacology


  • Potassium Channels
  • Pyridines
  • Sulfhydryl Reagents
  • 2,2'-dithiobis(5-nitropyridine)
  • Cysteine
  • Rubidium