Department of Chemistry, University of Karachi, Karachi 74900, Pakistan.
Spectrochim Acta A Mol Biomol Spectrosc. 2010 Dec;77(5):933-7. doi: 10.1016/j.saa.2010.08.020. Epub 2010 Aug 14.
The kinetics of iron removal from the two metal binding sites of the bovine lactoferrin by ethylenediaminetetraacetic acid (EDTA) was investigated at pH 7.5 and 33°C. Solutions were buffered at pH 7.5 by 0.15 M Tris-HCl. Pseudo first-order rate constants as a function of ligand concentration were measured for iron removal from diferric lactoferrin and from N- and C-terminal monoferric lactoferrin. Diferric lactoferrin showed simple saturation behavior while both the monoferric forms showed a two-term dependence of kobs on ligand concentration that signifies two pathways for iron removal under the conditions applied. Moreover, the results show that the N-terminal site is more labile towards iron removal by EDTA than the C-terminal site.
在 pH 值为 7.5 和 33°C 的条件下，研究了乙二胺四乙酸（EDTA）从牛乳铁蛋白的两个金属结合位点去除铁的动力学。溶液通过 0.15 M Tris-HCl 在 pH 值 7.5 下缓冲。测量了从高铁乳铁蛋白和 N-和 C-末端单铁乳铁蛋白中去除铁时，作为配体浓度函数的拟一级速率常数。高铁乳铁蛋白表现出简单的饱和行为，而两种单铁形式的 kobs 对配体浓度表现出二项依赖关系，这表明在应用条件下存在两种去除铁的途径。此外，结果表明，与 C-末端位点相比，N-末端位点对 EDTA 去除铁的反应更为活跃。
