A specific binding site for K+ channel openers in rat aorta.

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Bray KM, Quast U

A specific binding site for K+ channel openers in rat aorta.

J Biol Chem. 1992 Jun 15;267(17):11689-92.

PubMed ID

1601843 [ View in PubMed

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Abstract

The K+ channel openers, including cromakalim, pinacidil, minoxidil sulfate, diazoxide, and nicorandil, form a chemically heterogeneous group of compounds, which relax smooth muscle by opening plasmalemmal K+ channels. At present it is not known whether these drugs elicit their effects by binding to the same target, presumably the K+ channel. In order to address this question, a binding assay for K+ channel openers has been developed in vascular smooth muscle. The novel tritiated K+ channel opener, [3H]P1075, an analogue of pinacidil, binds with high affinity (KD = 6 +/- 1 nM) to endothelium-denuded rings of rat aorta. Inhibition studies indicate that the different families of K+ channel openers bind to a common target. Evidence is presented to suggest that the binding site for the sulfonylurea, glibenclamide, the major blocker of the K+ channel openers, is coupled in a negative allosteric manner to the binding site(s) for the openers. The binding assay described here may open the way to the biochemical characterization of the drug receptor for the K+ channel openers.

DrugBank Data that Cites this Article

Drug Targets

Drug	Target	Kind	Organism	Pharmacological Action	Actions
Minoxidil	ATP-sensitive inward rectifier potassium channel 1	Protein	Humans	Yes	Inducer	Details