FIG. 2.
Effects of CYL-I mutations on envelope protein synthesis and secretion. (A) Cellular proteins harvested at day 4 posttransfection (Cell) were separated on an acrylamide gel, transferred to a PVDF membrane, and probed with a mixture of anti-S and anti-preS2 antibodies (1:500 and 1:1,000, respectively). Signals are from 105 cells. (B) A pool of culture medium collected at days 2 and 4 posttransfection (Sup) was subjected to ultracentrifugation. Sedimented particles were disrupted in Laemmli buffer and analyzed as described above. Signals are from 1 ml of culture medium. Env(−), envelope protein negative; wt SML, wt S-, M-, and L-HBsAg. Molecular weights of the glycosylated (gp) and unglycosylated (p) forms of the HBV envelope proteins are indicated.