Observation of coherent reaction dynamics in heme proteins.
Observation of coherent reaction dynamics in heme proteins.
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DOI：
10.1126/science.7939716
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发表时间：
1994-10
期刊：
影响因子：
56.9
通讯作者：
Leyun Zhu;J. Sage;P. Champion
中科院分区：
文献类型：
--
作者：
Leyun Zhu;J. Sage;P. Champion
飞秒激光脉冲，与肌红蛋白（MbNO）的一氧化氮复合物的Soret带共振，被用来探测相干的，低频率的血红素组光解后的核运动。不同的振荡周期为430和150飞秒观察到，并归因于血红素拱和铁组氨酸运动，分别。这些结果验证了血红素的核运动强烈耦合到配体结合反应，并表明这种运动是不确定的过阻尼（扩散）动力学。的光产物的核运动的相对相位和频率表明，相干性产生于与血红素铁原子的自旋状态的变化和其dz2轨道在键断裂事件的人口减少相关联的脉冲电子力。
Femtosecond laser pulses, resonant with Soret band of the nitric oxide complex of myoglobin (MbNO), were used to probe coherent, low-frequency nuclear motion of the heme group after photolysis. Distinct oscillations with periods of 430 and 150 femtoseconds were observed and are attributed to heme doming and iron-histidine motion, respectively. These results verify that the nuclear motion of the heme is strongly coupled to the ligand binding reaction and demonstrate that such motion is not determined by overdamped (diffusive) dynamics. The relative phases and frequencies of the nuclear motion of the photoproduct suggest that the coherence arises from impulsive electronic forces associated with the spin-state change of the heme iron atom and the depopulation of its dz2 orbital during the bond-breaking event.