RESUMO
Objective:To isolate the variable fragments of heavy chain(VH) against the terminal protein(TP) region of hepatitis B virus(HBV) DNA polymerase(Pol) with protein fragment complementation assay(PCA).Methods:The TP region of HBV secreted by the HepG2.2.15 cells was used as an antigen,and the antibodies were selected with PCA.In this assay,two interacting proteins(target and antibody) are genetically fused to the two halves of the dissected enzyme dihydrofolate reductase.Binding of the two partners reassembles this enzyme and reconstitutes its activity,thus allowing growth on minimal mediem.Results:There were three TP region antigen-specific VHs could be directly in vivo selected with PCA.Sequence analysis showed that each TP-specific VH had a different sequence.Conclusion:Our results show that TP region antigen-specific VH could be directly in vivo selected with PCA.This system were powerful as a routine system for generating antibodies,especially in functional genomics.