DIFFERENCE BETWEEN 2 IRON-BINDING SITES OF TRANSFERRIN
DIFFERENCE BETWEEN 2 IRON-BINDING SITES OF TRANSFERRIN
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DOI：
10.1038/255087a0
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发表时间：
1975-01-01
期刊：
影响因子：
64.8
通讯作者：
ZAPOLSKI, EJ
中科院分区：
文献类型：
--
作者：
PRINCIOTTO, JV;ZAPOLSKI, EJ
转铁蛋白在铁的代谢中起着核心作用，在吸收、利用、排泄、回收和储存区域之间运输铁。虽然两个铁离子在表面上相等的铁结合位点上结合，但这些位点的行为却不相等。自Fletcher和Huehns2最初的报道以来，人们在体内和体外观察到每个位点结合的转铁蛋白铁具有独特的生物学特异性3 - 8。物理化学证据表明，每个位点的铁结合存在差异。Price和gibson9观察到在高氯酸盐的影响下，每个位点的电子顺磁共振（EPR）谱差异。Aisenet等人（10）观察了铬络合物的EPR位点之间的差异，Young和perkins11报道碳酸氢盐仅从（草酸）2 -铁2 -转铁蛋白络合物中置换了一个草酸阴离子。我们现在报告了不同转铁蛋白的ph依赖性解离实验，这表明每个位点的铁结合特性是不同的。
THE protein transferrin has a central role in iron metabolism, transporting the metal between absorption, utilisation, excretion, reclamation and storage areas. Although two ferric ions are bound at apparently equivalent iron-binding sites1, the sites behave in a non-equivalent manner. Since the initial report by Fletcher and Huehns2, there have been observationsin vivoandin vitroof the unique biological specificity for transferrin iron bound at each site3–8. Physicochemical evidence for any difference between iron binding at each site is sparse. Price and Gibson9observed electron paramagnetic resonance (EPR) spectral differences arising from each site under the influence of the chaotropic agent perchlorate. Aisenet al.10observed EPR differences between sites for the chromium complex and Young and Perkins11reported that bicarbonate displaces only one oxalate anion from the (oxalate)2–Fe2–transferrin complex. We now report experiments on thepH-dependent dissociation of diferric transferrin which indicate that there is a difference in the iron-binding properties of each site.