Abstract: Objective To investigate the mechanism of sulfhydrated Ras related protein 7a (Rab7a) in HepG2.2.15 cells and its effect on hepatitis B virus (HBV) replication. Methods The sulfhydrated Rab7a and sulfhydrated sites of Rab7a were verified by biotin switch method. The effect of the sulfhydrated Rab7a on the level of HBV replication markers was detected by enzyme-linked immunosorbent assay, RT-qPCR and Western blot. Results In HepG2.2.15 cells, H₂S enhanced the sulfhydration level of endogenous Rab7a (P＜0.01). NaHS (H₂S rapid release donor) enhanced the expression of sulfhydration of exogenous Rab7a, but the mutation of sulfhydration site was not affected by NaHS (P＜0.01). In HepG2.2.15 cells, H₂S enhanced the sulfhydrylation level of endogenous and exogenous Rab7a; the sulfhydrylated Rab7a inhibited the expression of HBsAg, HBeAg and HBV-DNA in supernatant, as well as HBV-cccDNA, 3.5RNA, total RNA and HBcAg protein in HepG2.2.15 cells (P＜0.05). Conclusions Sulfhydrated Rab7a inhibites the replication of HBV in HBV positive cell line HepG2.2.15.

Key words: sulfhydration, hepatitis B virus, Ras related protein 7a