2-(3-Methyl-3H-diaziren-3-yl)ethyl 1-(1-phenylethyl)-1H-imidazole-5-carboxylate: a derivative of the stereoselective general anesthetic etomidate for photolabeling ligand-gated ion channels.

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Husain SS, Ziebell MR, Ruesch D, Hong F, Arevalo E, Kosterlitz JA, Olsen RW, Forman SA, Cohen JB, Miller KW

2-(3-Methyl-3H-diaziren-3-yl)ethyl 1-(1-phenylethyl)-1H-imidazole-5-carboxylate: a derivative of the stereoselective general anesthetic etomidate for photolabeling ligand-gated ion channels.

J Med Chem. 2003 Mar 27;46(7):1257-65.

PubMed ID
12646036 [ View in PubMed
]
Abstract

To locate general anesthetic binding sites on ligand-gated ion channels, a diazirine derivative of the potent intravenous anesthetic, R-(+)-etomidate (2-ethyl 1-(1-phenylethyl)-1H-imidazole-5-carboxylate), has been synthesized and characterized. R-(+)-Azietomidate [2-(3-methyl-3H-diaziren-3-yl)ethyl 1-(1-phenylethyl)-1H-imidazole-5-carboxylate] anesthetizes tadpoles with an EC(50) of 2.2 microM, identical to that of R-(+)-etomidate. At this concentration both agents equally enhanced GABA-induced currents and decreased binding of the caged-convulsant [(35)S]TBPS to GABA(A) receptors. In all of the above actions R-(+)-azietomidate is about an order of magnitude more potent than S-(-)-azietomidate, an enantioselectivity comparable to etomidate's. R-(+)-Azietomidate also inhibits acetylcholine-induced currents in nicotinic acetylcholine receptors, with about twice the potency of the parent compound. [(3)H]Azietomidate photoincorporated into Torpedo nicotinic acetylcholine receptor-rich membranes. Desensitization decreased photoincorporation into the delta-subunit and increased that into the alpha-subunit. The latter increase was confined to a proteolytic fragment containing the first three transmembrane segments. Thus, R-(+)-azietomidate is a potent stereoselective general anesthetic and an effective photolabel.

DrugBank Data that Cites this Article

Binding Properties
DrugTargetPropertyMeasurementpHTemperature (°C)
EtomidateGamma-aminobutyric acid receptor subunit alpha-1IC 50 (nM)577000N/AN/ADetails
EtomidateGamma-aminobutyric acid receptor subunit alpha-1EC 50 (nM)1200N/AN/ADetails
EtomidateGamma-aminobutyric acid receptor subunit alpha-1EC 50 (nM)47000N/AN/ADetails
EtomidateGamma-aminobutyric acid receptor subunit alpha-1EC 50 (nM)2500N/AN/ADetails
EtomidateGamma-aminobutyric acid receptor subunit alpha-1IC 50 (nM)295000N/AN/ADetails
EtomidateGamma-aminobutyric acid receptor subunit alpha-1EC 50 (nM)64000N/AN/ADetails