Probing the Electronic Structure of the Hemoglobin Active Center in Physiological Solutions
Probing the Electronic Structure of the Hemoglobin Active Center in Physiological Solutions
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DOI：
10.1103/physrevlett.102.068103
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发表时间：
2009-02-13
影响因子：
8.6
通讯作者：
Chergui, Majed
中科院分区：
文献类型：
--
作者：
Aziz, Emad F.;Ottosson, Niklas;Chergui, Majed
首次报道了生理条件下牛血红蛋白和氯化血红素铁中心L（2，3）边的软X射线吸收光谱。提供固体形式的相同化合物的光谱以供比较。在液体和固体化合物之间观察到金属卟啉的电子结构的显著差异。我们毫不含糊地表明，血红蛋白和氯化血红素是在高自旋铁的状态在溶液中，2p自旋轨道耦合降低氯化血红素相比，血红蛋白，而这是不是在固体的情况下。用配位场多重态理论模拟了光谱，与实验结果吻合较好，可以定量分析血红蛋白和氯化血红素中卟啉与Fe（3+）离子之间的电荷转移量。
Soft-x-ray absorption spectroscopy at the L(2,3) edge of the iron center in bovine hemoglobin and hemin under physiological conditions is reported for the first time. Spectra of the same compounds in solid form are presented for comparison. Striking differences in the electronic structure of the metalloporphyrin are observed between the liquid and solid compounds. We unambiguously show that hemoglobin and hemin are in a high-spin ferric state in solution, and that the 2p spin-orbit coupling decreases for hemin compared to the hemoglobin, while this is not the case in solids. The spectra were simulated using ligand field multiplet theory, in good agreement with the experiment, allowing quantification of the amount of charge transfer between the porphyrin and Fe(3+) ion in hemoglobin and in hemin.