lactoferrin

(biochemistry) An iron-binding protein found in milk, saliva, tears, and intestinal and respiratory secretions that interferes with the iron metabolism of bacteria; in conjunction with antibodies, it plays an important role in resistance to certain infectious diseases.

Iron-protein complex in human milk (only a trace in cow's milk), only partly saturated with iron; has a rôle inhibiting the growth of E. coli and other potentially pathogenic organisms.

An iron binding protein found in the specific granules of neutrophils where it apparently exerts an antimicrobial activity by withholding iron from ingested bacteria and fungi. It also occurs in many secretions and exudates such as milk, tears, mucus, saliva, and bile.