Figure 5.

Properties of the nAChR from Torpedo californica after cross-linking with bis(sulfosuccinimidyl) suberate (BS³) and modification with MAI. (A) Gel electrophoresis of native nAChR (lane 1), Triton X-100-solubilized nAChR cross-linked with 0.5 mg/ml BS³ for 1 h (lane 2), nAChR-rich membranes cross-linked with 1.0 mg/ml BS³ for 1 h (lane 3), and nAChR-rich membranes cross-linked with 1 mg/ml BS³ for 2 h. The arrow indicates polymerized nAChR, which does not enter the gel. No intermediate stages of cross-linking can be seen with Triton-solubilized nAChR, indicating the lack of intersubunit cross-links. (B) [³H]ACh binding after modification with MAI (▵) and after cross-linking with BS³ (✠) as compared with native receptor (•).