ABSTRACT
Objective:To stablish of chemiluminescent Southern blot detection system for examining HBV DNA replication intermediates in HepG2.2.15,and analyse the inhibition of HBV replication with three kind of drugs with different targets.Methods:The HBV DNA replication intermediates were extracted and analyzed by Southern blot with HBV probe,which(pTHBV1047) was labelling with digoxigenin.The results of the hybridization were detected by chemiluminescent,and the condition of hybridization was optimized.After treated with lamivudine,Bay41-4109,?-Galcer in different concentration,the HBV DNA from the HepG2215 cells were detected with the system.Results:the sensitivity of the system was 1pg of pTHBV1047,and HBV specific positive signals was detected with the DNA from HepG2.2.15.The three kinds of drugs can inhibit the HBV replication obviously with chemiluminescent Southern blot detection system,the IC50 were 1.53?mol/L,0.41?mol/L,0.01?mol/L.Conclusion:The HBV replication intermediates from the cell of HepG2.2.15 can reflect the antiviral effect accurately with different targets drugs and this mothod would be used in the study of Chinese-midicine.
ABSTRACT
In order to produce recombinant human anti-HBsAg Fab antibody in Pichia pastoris, the recombinant yeast was fermented using fed-batch system in a 30 L bioreactor. The fermentation temperature was 30 degrees C, the pH was 5.0 approximately 5.3, and the DO was 20% approximately 30%. The recombinant Fab antibody was purified from crude culture supernatant by ion exchange and analyzed by SDS-PAGE and western blot and ELISA. When the absorbance (OD600) of broth reach 300 at the end of fed-batch phase, the induced phase was initiated. The results showed that recombinant human anti-HBsAg Fab antibody was high-level expressed in recombinant Pichia pastoris using a fed-batch fermentation system. Both chains of the Fab were successfully expressed upon methanol induction. After 192 h of induction, the expression level of recombinant Fab (soluble) reached 412 mg/L. The recombinant Fab antibody was purified effectively by ion-exchange chromatography from the fermentation supernatant to a purity of 95%. And the affinity activities of the purified recombinant Fab antibdy and fermentation supernatant were detected, and both of them showed high affinity activities. The results demonstrated that recombinant human anti-HBsAg Fab antibody could be high level produced by fed-batch fermentations in Pichia pastoris. Which can be efficiently used in industrial production.