Macara I G, Hoy T G, Harrison P M
Biochem J. 1973 Dec;135(4):785-9. doi: 10.1042/bj1350785.
Inhibition by Zn(2+) of iron uptake by apoferritin at very low substrate concentrations is shown to be competitive. It is proposed that Zn(2+) competes with Fe(2+) for sites on the protein at which the oxidation of Fe(2+) is catalysed. Interpretation of titration data suggests there are two independent classes of binding site for Zn(2+) and several other cations. Sites in one such class are probably on the external surface of the apoferritin molecule. The catalytic binding sites are presumed to be internal and may involve histidine or possibly cysteine as ligands.
已表明在极低底物浓度下，锌离子（Zn(2+)）对脱铁铁蛋白摄取铁的抑制作用具有竞争性。有人提出，Zn(2+)与亚铁离子（Fe(2+)）竞争蛋白质上催化Fe(2+)氧化的位点。滴定数据的解释表明，存在两类独立的锌离子及其他几种阳离子结合位点。其中一类位点可能位于脱铁铁蛋白分子的外表面。催化结合位点推测在内部，可能涉及组氨酸或半胱氨酸作为配体。
