Expression of human lactoferrin cDNA in insect cells

A transfer plasmid p8hLFc harboring human lactoferrin cDNA was constructed and co-transfected with Autographa californica nuclear polyhedrosis virus (AcNPV BacPAK6) DNA into Spodoptera frugiperda (Sf) cells. The recombinant virus AcNPV-hLFc was identified and purified three times by dot hybridization and plaques screening. The expression of human lactoferrin cDNA in insect cells was detected by Western blotting. The expression level of lactoferrin is about 2% of insect cellular total soluble proteins, and an amount of 9.5 mg/L lactoferrin is secreted into culture medium. Recombinant lactoferrin purified with affinity chromatography comigrates with human milk lactoferrin on SDS-polyacrylamide gels. In addition, the ration of A value at ultraviolet A₂₈₀/A₄₆₅ shows that the recombinant protein possesses iron-binding capacity.