Detection of nicotinic receptor ligands with a light addressable potentiometric sensor

✍ Scribed by Kim R. Rogers; John C. Fernando; Roy G. Thompson; James J. Valdes; Mohyee E. Eldefrawi

• Publisher: Elsevier Science
• Year: 1992
• Tongue: English
• Weight: 700 KB
• Volume: 202
• Category: Article
• ISSN: 0003-2697
• DOI: 10.1016/0003-2697(92)90215-s

✦ Synopsis

The nicotinic acetylcholine receptor, purified from Torpedo electric organ, was coupled to a light addressable potentiometric sensor (LAPS) to form a LAPS-receptor biosensor. Receptor-ligand complexes containing biotin and urease were captured on a biotinylated nitrocellulose membrane via a streptavidin bridge and detected with a silicon-based sensor. Competition between biotinylated alpha-bungarotoxin and nonbiotinylated ligands formed the basis of this assay. This biosensor detected both agonists (acetylcholine, carbamylcholine, succinylcholine, suberyldicholine, and nicotine) and competitive antagonists (d-tubocurarine, alpha-bungarotoxin, and alpha-Naja toxin) of the receptor with affinities comparable to those obtained using radioactive ligand binding assays. Consistent with agonist-induced desensitization of the receptor, the LAPS-receptor biosensor reported a time-dependent increase in affinity for the agonist carbamylcholine as expected, but not for the antagonists.