Figure 1

Expression and purification of hMPV and hRSV N proteins. His-tagged N proteins from E. coli BL21 (DE3) cell lysates or purified N proteins were examined by SDS-PAGE (upper panels) and Western blot analysis (bottom panels). Arrows indicate N protein bands and the bands detected by anti-His monoclonal antibody (Panel A, lane 3, 4; Panel B, lane 3, 4, 5). (A) Expression and purification of hMPV N protein. Lane 1, total protein extracted from E. coli BL21 (DE3) transformed with pET30a (+); lane 2, supernatant fraction from E. coli BL21 (DE3) transformed with pET-30a(+)-hMPV-N without IPTG induction; lane 3, supernatant fraction from E. coli BL21 (DE3) transformed with pET-30a(+)-hMPV-N induced by IPTG; lane 4, purified 6×His-tagged hMPV-N protein. (B) Expression and purification of hRSV N protein. Lane 1, total protein extracted from E. coli BL21 (DE3) transformed with pET30a (+); lane 2, supernatant fraction from E. coli BL21 (DE3) transformed with pET-30a(+)-hRSV-N without IPTG induction; lane 3, supernatant fraction from E. coli BL21 (DE3) transformed with pET-30a(+)-hRSV-N induced by IPTG; lane 4, hRSV-N protein purified using HisTrap Q FF column; lane 5, hRSV-N protein purified using HisTrap HP column. Lane M, molecular protein markers.