Figure 3.

Trypsin digestion of VLPs in the presence or absence of detergent. Purified VLPs were incubated with 1 μg/ml trypsin at 30°C for 30 min in the presence or absence of 1% Triton X-100, and Gag antigens were detected by Western blotting using anti-HIV-1 CA Ab. (A) VLPs purified from culture medium of yeast spheroplasts expressing Gag protein. (B) VLPs purified from culture medium of Sf9 cells expressing Gag protein. Lanes: M, prestained molecular weight markers; 1, untreated; 2, treated with detergent alone; 3, treated with trypsin alone; and 4, treated by a combination of detergent and trypsin.