In vitro cleavage of hepatitis B virus C mRNA by 10-23 DNA enzyme

10-23 DNA enzyme is one kind of deoxyribozymes for RNA cleavage. The inhibition effects of 10-23 DNA enzyme on the expression of the HBV C gene in HepG2.2.15 cells were demonstrated previously. The aim of this study was to further explore the cleavage activities of 10-23 DNA enzyme targeting at HBV C gene mRNA in vitro.

10-23 DNA enzyme named Drz-HBV-C-9 specific to HBV C gene ORF A(1816)UG was designed and synthesized. HBV C gene mRNA was obtained by the in vitro transcription method. Cleavage activities of Drz-HBV-C-9 were observed in vitro. Values of kinetic parameters including Km,Kcat and Kcat/Km were calculated accordingly.

Under the certain cleavage conditions, Drz-HBV-C-9 could efficiently cleave target mRNA at specific sites in vitro. Cleavage products of 109nt plus 191nt were obtained. The kinetic parameters, Km, Kcat and Kcat/Km for Drz-HBV-C-9, were 1.4 X 10(-9) mol, 1.6 min-1 and 1.1 X 10(9) mol(-1) x min(-1), respectively.

10-23 DNA enzyme targeting at HBV C gene mRNA possesses specific cleavage activities in vitro. This would be a potent antiviral strategy with respect to HBV gene therapy.