Manganese and Iron Binding to Human Transferrin

Abstract

The characteristics of manganese and iron binding to human apotransferrin (apo-tf) have been investigated and compared in this study. Both metal ions were taken up by human apo-tf and formed complexes, with the maximum absorbances observed at 410 and 340 nm for manganese-transferrin (Mn-tf) and 465 nm for iron-transferrin (Fe-tf). Addition of manganese (1.5 µg/ml) to the reaction mixture containing iron and apo-tf, reduced Fe binding to apo-tf by 20 percent, in comparison to the control sample. The binding of both metals to apo-tf appears to be time and pH dependent processes.