The effect of calcium ions in alpha-lactalbumin on the binding of fluo
ride ions was investigated. It has been disclosed that at pH 4.6 both
alpha-lactalbumin and apo-alpha-lactalbumin, when deprived of calcium
ions, fail to bind fluoride ions. At pH 3.7 the alpha-lactalbumin mole
cule and its calcium-free form of apo-alpha-lactalbumin do bind fluori
de ions but the mechanism of this bindings is variable.