Ultrastructural visualization of the transmembrane nicotinic AChR of frog motor endplate by means of an immunochemical reaction with d-tubocurarine.

Abstract

D-tubocurarine (d-TC) was used to block the synaptic transmission of frog neuromuscular junction. A recently discovered avidity of IgG for d-TC and also for other quaternary ammonium compounds (Tsuji et al 2003) was used to visualize the d-TC bound to the nicotinic acetylcholine receptor (nAChR) by means of an immunochemical reaction (immunoperoxidase). Regularly disposed transmembrane rod-like structures were observed through the postsynaptic membrane and interpreted as a staining of the interior side of the nAChR. Reference: Tsuji, S. et al (2003) Binding avidity of immunoglobulin G for acetylcholine. Biomed Res 24: 217-221 [J Physiol Sci. 2007;57 Suppl:S151]