Electrochemical and Solution Structural Characterization of Fe(III) Azotochelin Complexes: Examining the Coordination Behavior of a Tetradentate Siderophore.
Electrochemical and Solution Structural Characterization of Fe(III) Azotochelin Complexes: Examining the Coordination Behavior of a Tetradentate Siderophore.
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DOI：
10.1021/acs.inorgchem.2c02777
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发表时间：
2022-12-05
影响因子：
4.6
通讯作者：
Duhme-Klair, Anne -K.
中科院分区：
文献类型：
--
作者：
Baranska, Natalia G.;Parkin, Alison;Duhme-Klair, Anne -K.
我们报道了一种电化学装置，包括硼掺杂金刚石（BDD）工作电极，用于儿茶酚酸铁（III）铁载体的电化学研究。我们证明了它在铁（III）偶氮螯合物（双（儿茶酚酸）铁载体的铁配合物）伏安法研究中的成功应用。循环伏安法结果与紫外-可见和天然电喷雾电离-质谱（ESI-MS）表征相结合，揭示了在中性pH下Fe：偶氮螯合蛋白（M1:L1）形成的配位不饱和四配位1:1配合物，而其他类型的铁（III）四配位铁载体配合物则有利于M2:L3物种的六配位环境。pH和缓冲液组成对铁（III）偶氮chelin的还原电位有显著影响。较低的pH值和含有伯胺或仲胺的缓冲液，相对于Ag/AgCl 3 M NaCl，分别促进了+290 mV和+250 mV的正电位移动。该研究扩展到六齿铁载体的铁（III）配合物的研究。对于三（儿茶酚酸）铁载体、肠杆菌素和原螯虾素，发现还原电位超出了BDD电极可达的电位窗口；然而，我们成功地观察了三（羟酸）铁载体铁蛋白的电化学行为。采用掺杂硼金刚石电极伏安法、紫外可见光谱法和esi质谱法研究了四齿双（儿茶酚酸）铁络合物偶氮螯合素的铁（III）配合物。数据显示在pH 7.0下形成了一个配位不饱和的四配位M1:L1配合物。在pH < 6.25和含有伯胺和仲胺的缓冲液中分别观察到显著的正还原电位变化。在较低pH下的行为与分子内配位模式的变化一致，而不是复杂的化学计量。
We report an electrochemical setup comprising a boron-doped diamond (BDD) working electrode for the electrochemical study of iron(III) catecholate siderophores. We demonstrate its successful application in the voltammetric investigation of iron(III) azotochelin, an iron complex of a bis(catecholate) siderophore. Cyclic voltammetry results, when complemented by UV–vis and native electrospray ionization-mass spectrometry (ESI-MS) characterization, reveal the formation of a coordinatively unsaturated tetracoordinate 1:1 complex of Fe:azotochelin (M1:L1) at neutral pH, contrary to iron(III) tetradentate siderophore complexes of other classes which favor the hexacoordinate environment of an M2:L3 species. A notable effect of pH and buffer composition on the reduction potential of iron(III) azotochelin is demonstrated. Lower pH values and buffers encompassing primary or secondary amines facilitate a positive potential shift of up to +290 mV and +250 mV vs Ag/AgCl 3 M NaCl, respectively. The study was extended to the investigation of the iron(III) complexes of hexadentate siderophores. For tris(catecholate) siderophores, enterobactin and protochelin, the reduction potentials were found to lie beyond the potential window accessible to the BDD electrode; however, we were successful in observing the electrochemical behavior of a tris(hydroxamate) siderophore, ferricrocin. The iron(III) complex of azotochelin, a tetradentate bis(catecholate) siderophore, was investigated by voltammetry at a boron-doped diamond electrode, UV−vis spectroscopy, and native ESI-mass spectrometry. The data reveals formation of a coordinatively unsaturated tetracoordinate M1:L1 complex at pH 7.0. Significant positive reduction potential shifts are observed at pH < 6.25 and in buffers containing primary and secondary amines, respectively. The behavior at a lower pH is consistent with intramolecular changes in the coordination mode rather than complex stoichiometry.
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影响因子：
3.5
作者：
Harrington, James M.;Crumbliss, Alvin L.
通讯作者：
Crumbliss, Alvin L.
影响因子：
4
作者：
Ganne, Geraldine;Brillet, Karl;Schalk, Isabelle J.
通讯作者：
Schalk, Isabelle J.
影响因子：
15
作者：
HARRIS, WR;RAYMOND, KN;WEITL, FL
通讯作者：
WEITL, FL
影响因子：
4.6
作者：
Hou, ZG;Raymond, KN;Nishio, T
通讯作者：
Nishio, T
DOI：
10.1073/pnas.75.8.3551
发表时间：
1978-01-01
影响因子：
11.1
作者：
COOPER, SR;MCARDLE, JV;RAYMOND, KN
通讯作者：
RAYMOND, KN