Results indicated antibacterial activity to be present in pepsin-digested lactoferrin and F2 sample. Thus, purification of lactoferricin obtained through peptic digestion of bovine lactoferrin was accomplished by fractionation of the hydrolysate using cation exchange chromatography.
Lactoferrin (Lf) is an iron-binding glycoprotein and, as the name suggests, is a constituent of milk. It is also found, to a lesser extent, in various mucosal (exocrine) secretions of mammals that are commonly exposed to normal flora such as tears, nasal exudate, saliva, bronchial mucus, gastrointestinal fluids, cervicovaginal mucus and seminal fluid (Weinberg, 2003). Also, Lf is produced by secondary granules of polymorphonuclear neutrophils for deposition at septic sites. The granular contents of neutrophils can be released into inflammatory fluids after neutrophil death, by what is known as "holocrine secretion". The protein is closely related to transferrin, the iron-transport protein present in the plasma. Lactoferrin is a multifunctional innate-defense protein, known to exert a broad-spectrum primary defense activity against microbes including bacteria, fungi, protozoa and viruses (Orsi, 2004), and even some antibiotic-resistant pathogens (Wakabayashi et al., 2003). Lf is found in high concentrations in breast milk (~3–7 mg/ml) and tear fluid (1–4 mg/ml) (Rogan et al., 2006). Among the many constituents of milk which have revealed antimicrobial activity, lactoferrin exhibits both bacteriostatic and bactericidal activity against a wide array of microorganisms, including those causing gastroenteric infections, food poisoning, listeriosis and mastitis (Dionysius et al., 1993). Recently, clinical trials have demonstrated that bovine lactoferrin (bLF) administration can reduce the risk of colon carcinogenesis in humans (Tsuda et al., 2010). A key role of Lf is to scavenge non-protein-bound iron in body