Association of lactoferrin with other proteins, as demonstrated by changes in electrophoretic mobility.

Lactoferrin in a number of human body fluids was found to possess different electrophoretic mobilities, while being immunologically identical. The isolated protein migrated slower than any of the naturally occurring forms. This phenomenon was found to be due to the property of human lactoferrin to interact strongly with acidic macromolecules, forming complexes with a faster migration than the single protein. Beside electrostatic interactions also other forces seem to be involved in the complex formation.