Structural and functional interaction of (±)-2-(N-tert-butylamino)-3′-iodo-4′-azidopropiophenone, a photoreactive bupropion derivative, with nicotinic acetylcholine receptors

► SADU-3-72 is a promising photoprobe for mapping the BP binding site. ► Ca2+ influx results indicate that SADU-3-72 is 17- and 6-fold more potent than BP. ► SADU-3-72 interacts mainly with the binding site between valine and serine rings. ► BP/SADU-3-72 and TCP bind to overlapping sites within the lumen of muscle AChR.