Silver as a probe of pore-forming residues in a potassium channel.
In voltage-dependent potassium channels, the molecular determinants of ion selectivity are found in the P (pore) region, a stretch of 21 contiguous residues. Cysteine was introduced at each P region position in a Shaker potassium channel. Residues projecting side chains into the pore were identified by means of channel inhibition by a sulfhydryl-reactive potassium ion analog, silver ion. The pattern of silver ion reactivity contradicts a beta barrel architecture of potassium channel pores.
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Howard Hughes Medical Institute, Brandeis University, Waltham, MA 02254, USA.
Miller
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D000818:Animals; D003545:Cysteine / Q000494:pharmacology; D009154:Mutation; D009865:Oocytes; D018408:Patch-Clamp Techniques; D015221:Potassium Channels / Q000737:chemistry* / Q000235:genetics / Q000502:physiology; D051637:Shaker Superfamily of Potassium Channels; D012834:Silver; D014982:Xenopus laevis
D015221:Potassium Channels; D051637:Shaker Superfamily of Potassium Channels; D012834:Silver; D003545:Cysteine