Purification and antibacterial activity of recombinant human lactoferrin in milk of transgenic mice.

To check the antibacterial activity, the recombinant human lactoferrin (rhLF) was extracted from the milk of transgenic mices (Mus musculus) by gel filtration chromatography. The rhLF from the milk of transgenic mices (PCL25 and AP) were analyzed by SDS-PAGE, Western blot and ELISA assay. The bacteriostatic properties of rhLF were tested by agar disc diffusion method. The results indicated that the concentration of the hLF in the milk of transgenic mice ranged from 7 to 8 mg/mL when judged by ELISA analysis, the recombinant protein expressed in the milk had the same molecular weight as the native protein (about 78 kD) and the rhLFs had a strong antibacterial activity on Escherichia coli and Salmonella.