Mapping of MAb RB-E3 reactivity with MBPMSG truncated fusion proteins by SDS-PAGE, immunoblotting, and ELISA. (A) Coomassie blue-stained gel. (B) Immunoblot with anti-MBP polyclonal antisera. (C) Immunoblot with RB-E3. Lanes 1, MBP; lanes 2, native MSG; lanes 3, MBPMSG41–561; lanes 4, MBPMSG41–373; lanes 5, MBPMSG41–195; lanes 6, MBPMSG125–192; lanes 7, MBPMSG41–184; lanes 8, MBPMSG171–349. (D) ELISA analysis of MAb RB-E3 reactivity with MBPMSG-B truncated fusion proteins. Wells of 96-well microtiter plates were coated with the fusion proteins or MBP alone. The numbers correspond to the lanes described above. (E) Schematic of mapping of the epitope reactive with MAb RB-E3. The numbers in parentheses correspond to the lanes described above.