Relationship between the Electron Density of the Heme Fe Atom and the Vibrational Frequencies of the Fe-Bound Carbon Monoxide in Myoglobin
Relationship between the Electron Density of the Heme Fe Atom and the Vibrational Frequencies of the Fe-Bound Carbon Monoxide in Myoglobin
复制标题
血红素铁原子的电子密度与肌红蛋白中铁结合的一氧化碳的振动频率之间的关系
作者：
R. Nishimura;T. Shibata;H. Tai;I. Ishigami;T. Ogura;S. Nagao;T. Matsuo;S. Hirota;K. Imai;S. Neya;A. Suzuki;and Y;Yamamoto
我们分析了肌红蛋白中与铁结合的一氧化碳（CO）的振动频率，该肌红蛋白用一系列化学修饰的血红素辅因子重建，这些辅因子具有一个具有各种电子密度的血红素铁原子。研究表明，Fe束缚CO的伸缩振动频率（νCO）随血红素Fe原子的电子密度（ρFe）的减小而增大.这一发现表明，ν CO值可以作为ρ Fe值的灵敏度量，并且血红素Fe原子对CO的π反馈受外周侧链修饰引起的血红素π系统扰动的影响。
We analyzed the vibrational frequencies of the Fe-bound carbon monoxide (CO) of myoglobin reconstituted with a series of chemically modified heme cofactors possessing a heme Fe atom with a variety of electron densities. The study revealed that the stretching frequency of Fe-bound CO (νCO) increases with decreasing electron density of the heme Fe atom (ρFe). This finding demonstrated that the νCOvalue can be used as a sensitive measure of the ρFevalue and that the π back-donation of the heme Fe atom to CO is affected by the heme π-system perturbation induced through peripheral side chain modifications.