The novel compound Z060228 inhibits assembly of the HBV capsid.

AIMS: The effective anti-HBV drugs on the market are mainly immunomodulators or nucleoside analogs. The uses of INF-α and lamivudine (3TC) are considerably limited by their low response rate, side effects, drug resistance and HBV recurrence. Thus, new mechanism-based drugs remain in urgent need. This study aimed to investigate the anti-HBV effects of the novel compound Z060228 and to confirm its anti-HBV mechanisms.

MAIN METHODS: HepG2.2.15 cells and HBV-transgenic mice were used to evaluate the anti-HBV activity of Z060228. Conformational changes of the capsid structure induced by Z060228 were detected with high-resolution electron microscopy (EM), size-exclusion chromatography (SEC), and atomic force microscopy (AFM).

KEY FINDINGS: The HBV DNA replication in the supernatants of the HepG2.2.15 cells was effectively inhibited by Z060228 and Bay41-4109. In the liver of HBV-transgenic mice, the HBcAg content was significantly decreased and HBV DNA replication was also inhibited after high-dose (30 mg/kg) Z060228 treatment. Z060228 and Bay41-4109 exhibited similar effects on the self-assembly of Cp149. SEC data revealed that Z060228 altered the equilibrium (a state of stability) of Cp149 assembly. EM data further demonstrated that Z060228 could prevent Cp149 from self-assembling to the correct core particles. Additionally, AFM results showed that a low concentration of Z060228 caused Cp149 syncretizing, whereas a high concentration caused Cp149 to polymerize.

SIGNIFICANCE: Z060228 was demonstrated to be a potential capsid targeting anti-HBV drug candidate. The methods employed here could be used as a general strategy to study mechanisms of self-assembling protein-targeted drugs.