Expression of chimeric OMTs with N- and C-terminals derived from different OMTs. (A) The crude E. coli lysate (10 µg protein) expressing the chimeric OMTs was separated by SDS-PAGE and stained with Coomassie Brilliant Blue R250 (CBB). The molecular mass of the chimeric OMTs is ca. 40 kDa (indicated by arrow). (B) Immunoblot analysis with anti-4′-OMT polyclonal antibodies. (C) Immunoblot analysis with anti-SMT polyclonal antibodies. M, molecular mass markers; lane 1, pET-4′OMT; lane 2, pET-64′OMT; lane 3, pET-4′6OMT; lane 4, pET-S4′OMT; lane 5, pET-4′SOMT; lane 6, pET-S6OMT; lane 7, pET-6SOMT; lane 8, pET-SMT; lane 9, pET-21d (vector control).