Figure 3. Inhibition of [³H]-NMS binding to hM1 and hM4 receptors by wild-type MT7, MT1 and chimera toxins.

Binding experiments were performed by incubating hM1 (A) or hM4 (B) membrane fractions of receptor with [³H]-NMS (0.5 nM) and varying concentrations of toxin at room temperature and overnight. The total specific binding in each experiment was 1500±300 cpm. The results are expressed as the ratio of the specific [³H]-NMS binding measured with (B) or without toxin (B_o). All experiments were performed at least three times in duplicate.