Figure 4.

Torpedo nACh receptor photoincorporation. nACh receptor-rich membranes were photolabeled with 1.7 μM [³H]6 as described in the Experimental Section, and the polypeptides were then resolved by SDS-PAGE. (A) Polypeptides were visualized by Coomassie Blue stain (lane 1, a representative lane), and ³H distribution was determined by fluorography (lanes 2–9, 14 day exposure) for aliquots photolabeled in the absence of additional drugs (lanes 2 & 9), in the presence of 100 μM tetracaine (lane 3), 100 μM phencyclidine (lanes 4 & 7), 300 μM propofol (lanes 5 & 6), and in the presence of 1 mM carbamylcholine (Carb, lanes 6–8). Indicated on the left are the stained bands corresponding to the nACh receptor subunits (α, β, γ, & δ), rapsyn (Rsn), the α subunit of the Na⁺/K⁺-ATPase, calelectrin (37K), and the voltage dependent anion channel (VDAC).³⁹ (B) Quantification by liquid scintillation counting of the ³H incorporation into the gel bands containing the nACh receptor subunits.