Ultrafast dynamics of myoglobin without the distal histidine: Stimulated vibrational echo experiments and molecular dynamics simulations
Ultrafast dynamics of myoglobin without the distal histidine: Stimulated vibrational echo experiments and molecular dynamics simulations
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DOI：
10.1021/jp0517201
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发表时间：
2005-09-08
影响因子：
3.3
通讯作者：
Fayer, MD
中科院分区：
文献类型：
--
作者：
Finkelstein, IJ;Goj, A;Fayer, MD
用光谱分辨红外受激振动回波实验和分子动力学（MD）模拟研究了肌红蛋白突变体（H64V）的CO加合物的超快蛋白动力学行为。在室温下的水溶液中，CO在突变体中的振动失相速率相对于天然蛋白质降低了约50%。这一发现证实了天然蛋白中CO振动的失相对配体和远端组氨酸之间的相互作用敏感。可观察到的受激振动回波是从H64V的MD模拟计算的，在该模型中振动失相由静电力驱动。与实验一致，计算的振动回波显示出较慢的失相的突变体比天然蛋白质。然而，振动回波计算H64V不显示定量协议与测量先前证明的天然蛋白质。
Ultrafast protein dynamics of the CO adduct of a myoglobin mutant with the polar distal histidine replaced by a nonpolar valine (H64V) have been investigated by spectrally resolved infrared stimulated vibrational echo experiments and molecular dynamics (MD) simulations. In aqueous solution at room temperature, the vibrational dephasing rate of CO in the mutant is reduced by similar to 50% relative to the native protein. This finding confirms that the dephasing of the CO vibration in the native protein is sensitive to the interaction between the ligand and the distal histidine. The stimulated vibrational echo observable is calculated from MD simulations of H64V within a model in which vibrational dephasing is driven by electrostatic forces. In agreement with experiment, calculated vibrational echoes show slower dephasing for the mutant than for the native protein. However, vibrational echoes calculated for H64V do not show the quantitative agreement with measurements demonstrated previously for the native protein.