Figure 13.

Only IMR-32 AChRs immunoisolated with mAbs to α7 AChR subunit bind α-BGT. The bar graph depicts the relative amounts of ¹²⁵I-α-BGT binding that occurred on mAb-coated microwells after isolation of IMR-32 AChRs solubilized in Triton X-100. Microwells coated with a combination of mAbs 306 and 319 which both recognize α7 subunits bound 35-45 fmol of ¹²⁵I-α-BGT, whereas microwells coated with mAbs 210 (which recognizes α3 or α5 subunits) or 295 (which recognizes β2 subunits) exhibited virtually no binding above background for the same AChR extracts. Extracts from IMR-32 cells that had been treated overnight with Nic (100 μM) bound slightly less ¹²⁵I-α-BGT than cells that were not treated with Nic when bound on wells coated with mAbs 306/319.