Iron-Binding Properties of Bovine Lactoferrin in Iron-Rich Solution

¹ Nutritional Science Laboratory, Morinaga Milk Industry Co., Ltd., 1-83, 5-Chome, Higashihara, Zama-City, Kanagawa-Prefecture, 228, Japan

The iron-binding properties of bovine lactoferrin in iron-rich solution were investigated. Ferrous iron was not stable in solution and was easily changed to the insoluble ferric state, but solubility of ferrous iron was stabilized by the presence of lactoferrin. However, casein hydrolysate or BSA was not effective in stabilizing iron in solution. As indicated by use of cibacron blue affinity gel, iron bound to lactoferrin, and the charge of supersaturated lactoferrin was higher than that of normal iron-saturated lactoferrin according to native PAGE electrophoresis. The evidence suggests that lactoferrin can bind iron at sites other than its chelate-binding sites, thereby stabilizing iron in solution.

Key Words: lactoferrin • iron binding • affinity gel • electrophoresis

Submitted on August 12, 1992
Accepted on January 28, 1993