[Effect and mechanism of beta-L-D4A (a novel nucleoside analog) against hepatitis B virus]

To explore the effect and the molecular targets of anti-hepatitis B virus (HBV) by beta-L-D4A in vitro.

2.2.15 cells were cultured and treated with various concentrations of beta-L-D4A for 6 hours, then the effect of anti-HBV was examined by Southern blot and the replicating core particles from the cells were isolated. The endogenous polymerase reaction and activity gel experiment were performed to monitor the activities of the DNA polymerase and reverse transcriptase.

The replication of HBV DNA was inhibited in a dose-dependent manner. The endogenous polymerase reaction showed both the two enzymatic activities were irreversibly inactivated in a concentration -dependent manner, with IC50 at 0.51 micromol/L and 0.55 micromol/L, respectively. But the activities of DNA polymerase and reverse transcriptase were found to remain active by activity gel with exogenous templates.

The mechanism of inhibiting HBV replication by beta-L-D4A may be in that either the DNA replication priming is blocked or the elongation of DNA chain is terminated irreversibly.