Immunogen sequence: PQVLLMRWPL DKTRGTGSDA VPRGLARRPA KGKLASHGEP RHLKECFHCH KSNELATSKR RLSHQPLQWV VENSEHSPEV EDVINSVQFI A. After binding acetylcholine, the AChR responds by an extensive change in conformation that affects all subunits and leads to opening