The effect of salt concentration on the iron-binding properties of human transferrin

Abstract
The salt dependence of the Fe-binding properties of transferrin was studied by urea/polyacrylamide-gel electrophoresis. The distribution of Fe between the N-terminal and C-terminal binding sites under equilibrium conditions and the rates of release of FE from the 2 sites were studied. Salt increases the thermodynamic stability of Fe binding in the N-terminal site relative to the C-terminal site. Similar behavior is observed for the kinetics of Fe release, where salt retards the rate of removal of Fe from the N-terminal site but facilitates removal from the C-terminal site.