Expression of cardiac troponin I in baculovirus system

Objective: To express cardiac troponin I (cTnI) in baculovirus system. Methods: The cTnI gene with 6 x His tag was subcloned to baculovirus transfer vector pFastBac-dual (pFBd). The constructed recombinant transfer plasmid pFBd-cTnI was transformed to competent E. coli DH10Bac, based on which recombinant bacmid rbacmid-cTnI was screened and transfected to Sf9 cells. The expression of cTnI protein was determined by SDS-PAGE and Western blot. Results: PCR proved that rbacmid-cTnI was constructed correctly. The cTnI protein, with a relative molecular mass of about 25 000, was expressed in Invitrogen straion of Sf9 cells transfected with rbacmid-cTnI, and was recognized by mouse monoclonal antibody against His tag and rabbit polyclonal antibody against cTnI. Conclusion: The cTnI protein was successfully expressed in Sf9 cells, which laid a foundation of further preparation of cTnI protein and development of test method for cTnI.