INTERACTION OF BOVINE LACTOFERRIN WITH OTHER PROTEINS OF MILK WHEY

The association between bovine lactoferrin and the major bovine whey proteins, β-lactoglobulin, α-lactalbumin and albumin has been studied by immunochemical techniques, gel filtration and affinity chromatography in lacteal secretions and using purified proteins. Bovine lactoferrin is able to form non-covalent complexes with β-lactoglobulin or albumin, with lactoferrin-protein molar ratios of 2:1 and 1:1 respectively. No association was detected with α-lactalbumin. Lactoferrin interacts with β-lactoglobulin-Sepharose at low ionic strength, but not in the presence of 0.3 m NaCl, indicating that ionic interactions are important. The lack of association with α-lactalbumin suggests however a certain degree of specificity in this electrostatic interaction. © 1990.