Dedman D J, Treffry A, Harrison P M
Department of Molecular Biology and Biotechnology, University of Sheffield, U.K.
Biochem J. 1992 Oct 15;287 ( Pt 2)(Pt 2):515-20. doi: 10.1042/bj2870515.
Horse spleen ferritin was found to bind aluminium poorly after equilibrium dialysis with buffered aluminium citrate solutions. Not more than 10 aluminium atoms/ferritin molecule were bound from a 25 microM-aluminium solution, pH 7.4, and the degree of binding was dependent on the method used to prepare the aluminium citrate solution. Up to 120 aluminium atoms/molecule were bound when ferritin iron cores were reconstituted by the addition of 3000 Fe atoms to apoferritin in the presence of aluminium citrate. Comparison of previously published binding constants of ferritin and citrate for aluminium suggests that, in the cell, the prevalence of small ligands effectively prevents the association of large amounts of aluminium with ferritin.
在用缓冲柠檬酸铝溶液进行平衡透析后，发现马脾铁蛋白与铝的结合能力较差。在pH 7.4的25微摩尔铝溶液中，每个铁蛋白分子结合的铝原子不超过10个，且结合程度取决于制备柠檬酸铝溶液的方法。当在柠檬酸铝存在的情况下向脱铁铁蛋白中添加3000个铁原子来重构铁蛋白铁芯时，每个分子可结合多达120个铝原子。先前发表的铁蛋白和柠檬酸与铝的结合常数比较表明，在细胞中，小分子配体的普遍存在有效地阻止了大量铝与铁蛋白的结合。
