Zn2+ inhibits the anion transport activity of band 3 by binding to its cytoplasmic tail.

Zn2+ can induce a conformational change of Band 3 with concomitant inhibition of its anion transport activity of human erythrocyte membrane vesicles only from the cytoplasmic side. The Zn2+ inhibition exhibits a dose-dependent manner with an apparent half maximal concentration of 50 microM ZnCl2 and can be reversed by 0.5 mM EDTA, but not by 1 mM dithiothreitol. The Zn2+ effect is specific and no similar inhibitory action could be observed by other divalent cations (Cu2+, Mn2+, Mg2+ or Sr2+).