Direct observation of ultrafast collective motions in CO myoglobin upon ligand dissociation
Direct observation of ultrafast collective motions in CO myoglobin upon ligand dissociation
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DOI：
10.1126/science.aac5492
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发表时间：
2015-10-23
期刊：
影响因子：
56.9
通讯作者：
Schlichting, Ilme
中科院分区：
文献类型：
--
作者：
Barends, Thomas R. M.;Foucar, Lutz;Schlichting, Ilme
血红素蛋白肌红蛋白是研究蛋白质动力学的模型系统。我们使用时间分辨连续飞秒晶体学在X射线自由电子激光器解决超快结构变化的碳一氧肌红蛋白复合物光解后的Fe-CO键。在500飞秒内，整个蛋白质的结构发生变化，C、F和H螺旋远离血红素辅因子，E和A螺旋向血红素辅因子移动。这些集体运动是通过混合量子力学/分子力学模拟预测的。与所观察到的振荡接触血红素的残基一起，我们的计算支持的预测，立即发生的蛋白质的集体反应后，配体解离，作为血红素振动模式耦合到全球模式的蛋白质的结果。
The hemoprotein myoglobin is a model system for the study of protein dynamics. We used time-resolved serial femtosecond crystallography at an x-ray free-electron laser to resolve the ultrafast structural changes in the carbonmonoxy myoglobin complex upon photolysis of the Fe-CO bond. Structural changes appear throughout the protein within 500 femtoseconds, with the C, F, and H helices moving away from the heme cofactor and the E and A helices moving toward it. These collective movements are predicted by hybrid quantum mechanics/molecular mechanics simulations. Together with the observed oscillations of residues contacting the heme, our calculations support the prediction that an immediate collective response of the protein occurs upon ligand dissociation, as a result of heme vibrational modes coupling to global modes of the protein.