In vitro protein expression of Apoptin and truncated proteins. The expressed proteins were analyzed through Western blot assay by anti-VP3 and anti-MBP mAbs. The expressed proteins were tagged with MBP, thus showed higher molecular weight (MW) instead of the original MW of wild-type Apoptin. The MW of Apoptin is 13.6 kDa. The MW of wild-type full length Apoptin and truncated Apoptin proteins tagged MBP varies from 47.5-62 kDa. Lane A1: PrVP3, lane A2: PrVP3A1-69N1N2, lane A3: PrVP3A1-46N1N2 and lane A4: PrVP3A1-31N1N2 were analysed by anti-VP3 mAb. Lane B1: PrVP3A32-69N1N2 and lane B2: PrVP3A32-62N1N2 were analyzed by anti-MBP mAb. Lane A5 and B3: Protein Marker (NEB, UK).