Figure 3

The mechanism for CMK to accumulate cytosolic HBcAg and pre-HBe. Recombinant HBcAg with 6 × his-tag in the C-terminus (rHBc) was digested by trypsin, and the products were demonstrated using Western blot analysis with either a polyclonal antibody to HBcAg (anti-core) or monoclonal antibody to 6 × his-tag (anti-his-tag). Proteasome activities were demonstrated using a commercial system, and results were expressed as times of the protease activities of the treatment groups over those of the control group. Columns and vertical bars represented the mean ± SD of three separate experiments. *P < 0.05 and **P < 0.01. A: CMK inhibited trypsin to digest rHBc into truncated fragments of 16 kDa (F/16kD). The truncated rHBc lost the 6 × his-tag. B: rHBc was not digested by the cytosolic extract from HepG2 cells. C: CMK selectively inhibited the TL activity when cells were treated for 2 hours. D: CMK did not affect the α and β subunits of proteasomes (α + β/subunits) in protein levels when compared with the housekeeping gene (β-actin). E: CMK selectively inhibited the TL activity when cell lysates were treated for 2 hours. F: D6R (100 μmol/L) and the prosegment expression did not affect the activities of proteasomes.