FIG. 3.

Functional analysis of the six pre-S1 mutations in the same WT core gene context via assays for both intracellular HBV DNA replication (a) and extracellular virion secretion (b). The low-secretion phenotype was observed in both mutants L112F and A119F. Briefly, 2 μg of each plasmid DNA was transfected into a human hepatoma cell line HepG2 using the FuGENE 6 reagent and protocol (Roche). Intracellular core particles were harvested 5 days posttransfection, and the core particle-associated HBV DNA was analyzed by Southern blot with a 3.1-kb HBV double-stranded DNA probe. The virion secretion assay was as described for Fig. 1. The full-length RC-form DNA at 4.0 kb and the SS-form DNA at 1.5 kb are indicated. The tandem dimer of WT HBV DNA was included as a control.