Lactoferrin

Lactoferrin (LF), a globular multifunctional protein with antimicrobial activity (bacteriocide, fungicide), is part of the innate defense, mainly at mucoses. Lactoferrin is found in milk and many mucosal secretions such as tears and saliva. Lactoferrin is also present in secondary granules of PMN and also is secreted by some acinar cells. Human colostrum has the highest concentration, followed by human milk, then cow milk.

Structure
Lactoferrin belongs to the transferrin family proteins (TF, melanotransferrin, ovotransferin, etc.). Its molecular mass is 80,000 u (80 kDa).

Function
Lactoferrin antimicrobial activity is due partly to its high affinity for Fe (ferric state). LF proteolysis produces lactoferricin, kaliocin-1 small peptides with antimicrobial activity.

Lactoferrin receptors have been found on brush-border cells, PMN, monocytes, Mφ and activated lymphocytes.

Genetics
Genetically modified (transgenic) rice LL601 (Liberty Link 601) produces this protein.