title: A possible biological role of the electron transfer between tyrosine and tryptophan. Gating of ion channels.
abstract: Experiments have demonstrated that four tryptophan residues are located near the tetrodotoxin binding site in Na+ channels, and that conserved tyrosine and tryptophan residues are located in the pore-forming region of voltage-sensitive K+ channels. This paper proposes an activation mechanism involving electron transfer between these residues. The K+ channel may be closed by four tyrosine residues forming hydrogen bonds with each other. After electron transfer, these hydrogen bonds will be broken, thereby opening the channel. The Na+ channel could be activated by a similar mechanism. This idea can be tested directly by observing tyrosine or tryptophan radicals when the channels are in the open state.
authors.affiliation: Chemical Dynamics Corporation, Guilderland, NY 12084.
authors.forename: C Y
authors.initials: CY
authors.lastname: Lee
mesh_terms: D004579:Electron Transport; D005609:Free Radicals; D015640:Ion Channel Gating; D015222:Sodium Channels / Q000378:metabolism*; D014364:Tryptophan / Q000378:metabolism*; D014443:Tyrosine / Q000378:metabolism*
chemical_list: D005609:Free Radicals; D015222:Sodium Channels; D014443:Tyrosine; D014364:Tryptophan