The influence of inorganic anions on the formation and stability of Fe3+-transferrin-anion complexes.
The influence of inorganic anions on the formation and stability of Fe3+-transferrin-anion complexes.
复制标题
无机阴离子对Fe3-转铁蛋白-阴离子复合物形成和稳定性的影响。
DOI：
10.1016/0304-4165(88)90051-7
复制
发表时间：
1988
期刊：
影响因子：
--
通讯作者：
Bates,GW
中科院分区：
文献类型：
--
作者：
Foley,AA;Bates,GW
Harris（Biochemistry 24（1985）7412）报道了无机阴离子以干扰紫外光谱的方式与人脱铁转铁蛋白结合。结合位点被认为涉及特定的金属/阴离子结合位点，因为没有观察到Fe 3 +-转铁蛋白-CO 32 −的扰动。奇怪的是，尽管存在高浓度的SO 42 −、H2 PO 4 −、Cl−、ClO 4 −或NO3−，我们仍无法证明Fe 3 +-转铁蛋白-无机阴离子复合物的形成。对于人乳铁蛋白也发现了类似的结果。采用电子顺磁共振光谱法和可见分光光度法进行监测。试图通过从Fe 3 +-转铁蛋白-甘氨酸中置换甘氨酸来形成H2 PO 4 −复合物，结果只破坏了三元复合物。一系列无机阴离子在pH 5.5时从Fe 3 +-transferrin-CO 3 Psu 2 −中释放铁的能力各不相同，pH 5.5是细胞内发生铁释放的内体的近似pH。有效性的顺序为H2 P2 O 72 − → H2 PO 4 −> SO 42 −>NO3−>Cl−> ClO 4 −。在pH 5.5下，通过4倍过量的焦磷酸盐从Fe 3 +-转铁蛋白-CO 32 −中去除铁的速率被生理NaCl浓度大大增强。铁的去除在10分钟内完成，这是发育中的红系细胞中Fe 3 +-转铁蛋白-CO 32 −释放铁的近似时间。因此，尽管无机阴离子不能发挥协同阴离子的作用，但在生理条件下，无机阴离子可能对铁的释放具有显着影响。结果进行了讨论，在一个特殊的作用，允许三元复合物的形成羧酸基团。
Harris (Biochemistry 24 (1985) 7412) reports that inorganic anions bind to human apotransferrin in such a way as to perturb the ultraviolet spectrum. The locus of binding is thought to invole the specific metal/anion-binding sites since no perturbation is observed with Fe3+-transferrin-CO32−. Paradoxically, we were unable to demonstrate the formation of Fe3+-transferrin-inorganic anion complexes despite the presence of high concentrations of SO42−, H2PO4−, Cl−, ClO4−or NO3−. Similar results were found for human lactoferrin. Electron paramagnetic resonance spectroscopy and visible spectrophotometry were used to monitor the results. An attempt to form the H2PO4−complex by displacement of glycine from Fe3+-transferrin-glycine resulted only in the disruption of the ternary complex. A series of inorganic anions varied in their ability to release iron from Fe3+-tranferrin-CO3Psu2− at pH 5.5, the approximate pH of endosomes where iron release takes place within cells. The order of effectiveness was H2P2O72−⪢H2PO4−>SO42−>NO3−>Cl−>ClO4−. The rate of iron removal from Fe3+-transferrin-CO32−at pH 5.5 by a 4-fold excess of pyrophosphate was greatly enhanced by physiological NaCl concentration. Iron removal was complete within 10 min, the approximate time for iron release from Fe3+-transferrin-CO32−in developing erythroid cells. Thus, inorganic anions may have a significant effect on the release of iron under physiological conditions despite the fact that such inorganic anins cannot act as synergistic anins. The results are discussed in relation to a special role for the carboxylate group in allowing ternary complex formation.
登录
查看更多内容
通过 Fe2 的结合和氧化形成 Fe3 -转铁蛋白-CO3(2-)。
DOI：
--
发表时间：
1981
期刊：
The Journal of biological chemistry
影响因子：
--
作者：
Kojima,N;Bates,GW
通讯作者：
Bates,GW
影响因子：
2.9
作者：
FOLEY, AA;BATES, GW
通讯作者：
BATES, GW
影响因子：
15
作者：
FOLAJTAR, DA;CHASTEEN, ND
通讯作者：
CHASTEEN, ND
DOI：
--
发表时间：
1986
期刊：
The Journal of biological chemistry
影响因子：
--
作者：
Cowart,RE;Swope,S;Loh,TT;Chasteen,ND;Bates,GW
通讯作者：
Bates,GW
使用碳 13 核磁共振波谱研究转铁蛋白与阴离子的结合。
影响因子：
2.9
作者：
J. Zweier;J. B. Wooten;J. Cohen
通讯作者：
J. Cohen