title: On the activation-inactivation coupling in Shaker potassium channels.
abstract: The 'ball-and-chain' model suggests the existence of a negative site which may attract the positively charged inactivation ball to occlude the pore when the channel is in the open state. For Shaker K+ channels, we propose that the state-dependent negative site be tryptophan-435, which becomes negatively charged after receiving an electron from tyrosine-445. The kinetic scheme for the channel's activation-inactivation coupling as derived from the YW-gated model resembles a successful 'scheme 8' proposed by Zagotta and Aldrich. Our model suggests that the final rapid voltage-independent transition to the open state is due to the deprotonation of tyrosine-445.
authors.affiliation: Chemical Dynamics Corporation, Guilderland, NY 12084.
authors.forename: C Y
authors.initials: CY
authors.lastname: Lee
mesh_terms: D004579:Electron Transport; D015640:Ion Channel Gating; D007700:Kinetics; D008956:Models, Chemical; D015221:Potassium Channels / Q000378:metabolism*; D014443:Tyrosine / Q000378:metabolism
chemical_list: D015221:Potassium Channels; D014443:Tyrosine