Referenced in: none

Automatically associated channels: Kir1.1

Title: Purification, characterization, and synthesis of an inward-rectifier K+ channel inhibitor from scorpion venom.

Authors: Z Lu, R MacKinnon

Journal, date & volume: Biochemistry, 1997 Jun 10 , 36, 6936-40

PubMed link: http://www.ncbi.nlm.nih.gov/pubmed/9188688

Abstract
We have purified a protein inhibitor of an inward-rectifier K+ channel, ROMK1, from the venom of the scorpion Leiurus quinquestriatus var. hebraeus. The inhibitor is Lq2, a previously discovered blocker of voltage- and Ca2+-activated K+ channels. Mutations were made on the channel and the inhibitor, and the resulting effects were examined using an electrophysiological assay. The data show that Lq2 blocks the pore of ROMK1, and that the interaction surface on Lq2 is the same for binding to inward-rectifier, voltage-activated, or Ca2+-activated K+ channels. These findings support the notion that different classes of K+ channels have different gates but a similar K+-selective pore structure.