Figure 2.

Design of a biotinylated version of BVDV E2. (A) Schematic representation of the secreted version of BVDV E2 expressed in insect cells. C-terminally truncated E2 (E2∆) was fused to baculovirus GP64 signal peptide (sp) and biotin acceptor peptide (BAP) sequences at the N-terminus and to a 6xHis tag (6xH) at the C-terminus. (B) Site specific biotinylation of E2 in cells expressing E. coli biotin ligase BirA. The supernatants of parental or BirA expressing Sf9 cells infected with the recombinant baculovirus bearing BAP-E2 expression cassette were resolved in SDS-PAGE and subjected to Western blotting with HRP-conjugated streptavidin (left) or a polyclonal antibody against 6xHis (right). (C) Expression of wild type and mutant E2 in insect cells. Coomassie Blue staining (left) and Western blot against E2 (right) of the purified proteins resolved by SDS-PAGE.