FIG. 4.

Time course of S. litura APN expression in Sf21 insect cell culture. U, total cell extract of uninfected cells. BV-SlApn-infected Sf21 cells (10⁶) were harvested at the indicated times. Total cell extract was resolved by SDS-7.5% PAGE and electrotransferred to nitrocellulose membrane. Western blot analysis was carried out with (i) polyclonal antibodies raised against APN and (ii) monoclonal anti-histidine tag antibodies. Bands A and B represent the two forms of APN expressed in the Sf21 cells. The positions of molecular mass markers (in kilodaltons) are indicated on the left.