Detection of nicotinic receptor ligands with a light addressable potentiometric sensor.

K R Rogers, J C Fernando, R G Thompson, J J Valdes, M E Eldefrawi

Department of Pharmacology and Experimental Therapeutics, University of Maryland, School of Medicine, Baltimore 21201.

Analytical biochemistry 1992 Apr

filter terms:

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.

Citation

K R Rogers, J C Fernando, R G Thompson, J J Valdes, M E Eldefrawi. Detection of nicotinic receptor ligands with a light addressable potentiometric sensor. Analytical biochemistry. 1992 Apr;202(1):111-6