Price D J, Joshi J G
Toxicology. 1984 May 14;31(2):151-63. doi: 10.1016/0300-483x(84)90007-6.
Ferritin binds a large quantity of Be2+ (Price D.J. and Joshi, J.G. J. Biol. Chem. 258 (1983) 10873) as well as other divalent metal ions. Therefore the ability of this protein to protect enzymes against or reverse the inhibition by metal ions was studied. Evidence presented here shows that the inhibition by Be2+ of the enzymes Na+K+ATPase, alkaline phosphatase and phosphoglucomutase is reversed by ferritin. Be2+ can be transferred reversibly between phosphoglucomutase and ferritin depending upon the relative concentrations of the 2 proteins. Ferritin also reactivated phosphoglucomutase inhibited by Zn2+, Cu2+, or Cd2+. Incubation of ferritin containing Be2+ with 4-10 fold molar excess of phosphoglucomutase (with respect to Be2+) removed 90% of the Be2+ from ferritin. The rates of inactivation of phosphoglucomutase by Be2+ donated by apoferritin or ferritin were identical. Based upon these observations it is suggested that Be2+ bound to the protein shell and to the iron core are in equilibrium with each other with the equilibrium favoring ferritin-Be2+ complex.
铁蛋白能结合大量的Be2+（普赖斯D.J.和乔希J.G.，《生物化学杂志》258卷（1983年）第10873页）以及其他二价金属离子。因此，研究了这种蛋白质保护酶免受金属离子抑制或逆转金属离子抑制作用的能力。此处提供的证据表明，铁蛋白可逆转Be2+对Na+K+ATP酶、碱性磷酸酶和磷酸葡萄糖变位酶的抑制作用。根据两种蛋白质的相对浓度，Be2+可在磷酸葡萄糖变位酶和铁蛋白之间可逆转移。铁蛋白还能使受Zn2+、Cu2+或Cd2+抑制的磷酸葡萄糖变位酶重新激活。将含Be2+的铁蛋白与摩尔量过量4 - 10倍的磷酸葡萄糖变位酶（相对于Be2+）一起孵育，可使铁蛋白中90%的Be2+去除。脱铁铁蛋白或铁蛋白提供的Be2+使磷酸葡萄糖变位酶失活的速率相同。基于这些观察结果，有人提出，结合在蛋白质外壳和铁芯上的Be2+相互处于平衡状态，且平衡有利于铁蛋白 - Be2+复合物。
