Picosecond structural dynamics of myoglobin following photodissociation of carbon monoxide as revealed by ultraviolet time-resolved resonance Raman spectroscopy
Picosecond structural dynamics of myoglobin following photodissociation of carbon monoxide as revealed by ultraviolet time-resolved resonance Raman spectroscopy
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DOI：
10.1021/bi051732c
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发表时间：
2005-11-15
期刊：
影响因子：
2.9
通讯作者：
Mizutani, Y
中科院分区：
文献类型：
--
作者：
Sato, A;Mizutani, Y
利用时间分辨紫外共振拉曼光谱首次以位点特异性方式观察到肌红蛋白响应CO解离后血红素结构变化的皮秒蛋白质动力学。瞬态紫外共振拉曼光谱表明，色氨酸和酪氨酸的拉曼带强度变化的几个阶段。解离后5皮秒，色氨酸残基的W18、W16和W3带以及酪氨酸残基的Y8a带的强度降低，随后在数百皮秒内恢复Y8a带强度，并在纳秒内恢复色氨酸带。这些光谱变化表明，血红素结构的变化冲动地驱动EF螺旋部分的协同运动，并且在亚纳秒至纳秒的时间范围内，在血红素附近和A螺旋中发生朝向脱氧结构的rebeneficients。
Picosecond protein dynamics of myoglobin in response to structural changes in heme upon CO dissociation were observed in a site-specific fashion for the first time using time-resolved UV resonance Raman spectroscopy. Transient UV resonance Raman spectra showed several phases of intensity changes in both tryptophan and tyrosine Raman bands. Five picoseconds after dissociation, the W18, W16, and W3 bands of tryptophan residues and the Y8a band of tyrosine residues decreased in intensity, followed by recovery of the Y8a band intensity in hundreds of picoseconds and recovery of the tryptophan bands in nanoseconds. These spectral changes suggest that the change in heme structure impulsively drives concerted movement of the EF helical section and that rearrangernents toward a deoxy structure occur in the heme vicinity and in the A helix within a time frame of sub-nanoseconds to nanoseconds.