Kinetic characterization of reductant dependent processes of iron mobilization from endocytic vesicles

The reductant dependence of iron mobilization from isolated rabbit reticulocyte endosomes containing diferric transferrin is reported. The kinetic effects of acidification by a H + -ATPase are eliminated by incubating the endosomes at pH 6.0 in the presence of 15 μM FCCP to acidify the intravesicular milieu and to dissociate 59 Fe(III) from transferrin. In the absence of reductants, iron is not released from the vesicles, and iron leakage is negligible