The effect of saturation with Zn2+ and other metal ions on the antibacterial activity of ovotransferrin.

The antibacterial activity of metal complexes of ovotransferrin was tested "in vitro" against different bacterial species and the Zn2+ saturated ovotransferrin appeared to be the most active by comparison with the apo-protein and other metal complexes. Appropriate controls showed that such an effect was neither due to Zn2+ ions, nor to iron deprivation, but to a specific activity of the Zn-ovotransferrin complex. This antibacterial activity required a direct contact of Zn-ovotransferrin with the bacterial surface. In vivo experiments confirmed the higher antibacterial activity of Zn-ovotransferrin as compared with the apo-form.