Functionality of soluble scFvE2/p17: antigen recognition. Sf9 cells were mock-infected or infected with BVCAR (expressing irrelevant recombinant protein), or BV-E2/p17, and harvested at 48 h pi. Sf9 cell lysates were clarified by centrifugation, and reacted in ELISA with immobilized antigen. (a), H6MA-CA protein; (b, c), synthetic peptide p17.1 (121DTGHSSQVSQNY132 epitope). Negative controls were, from left to right: uncoated well, antigen-coated well without addition of scFvE2/p17-containing lysate, mock-infected cell lysate, and BVCAR-infected cell lysate, respectively. (c), Dose-dependent immunoreactivity of scFvE2/p17 towards p17.1 peptide. Soluble scFvE2/p17 from Sf9 cell lysates was affinity-purified on anti-HA tag antibody-coupled agarose beads. Average of three separate experiments, m ± SEM; (**), P < 0.01; ns, not significant.