cis-3,3'-Bis-[alpha-(trimethylammonium)methyl]azobenzene (cis-Bis-Q). Purification and properties at acetylcholine receptors of Electrophorus electroplaques.
The cis and trans isomers of the photoisomerizable compound, 3,3'-bis-[alpha-(trimethylammonium)methyl]azobenzene (Bis-Q), were purified by high-performance liquid chromatography using the ion-pair partitioning technique on a reverse-phase column. Solutions of cis-Bis-Q are stable at -20 degrees; at 25 degrees, thermal isomerization proceeds at a rate of 0.65%/day. cis-Bis-Q is less than 1% as potent a nicotinic agonist as the trans configuration. At concentrations of 1.5 microM or less, cis-Bis-Q exerts little or no blockade of the conductances induced by agonists. In voltage-clamped Electrophorus electroplaques exposed to cis-Bis-Q, laser flashes induce cis leads to trans photoisomerizations and increase the agonist-induced current by a factor of 20 within a few milliseconds.
D000818:Animals; D002851:Chromatography, High Pressure Liquid; D004557:Electric Organ / Q000187:drug effects*; D004593:Electrophorus; D007536:Isomerism; D007834:Lasers; D010777:Photochemistry; D000644:Quaternary Ammonium Compounds / Q000302:isolation & purification / Q000494:pharmacology*; D011950:Receptors, Cholinergic / Q000187:drug effects*
D000644:Quaternary Ammonium Compounds; D011950:Receptors, Cholinergic; C000295:Bis-Q