Investigations of the low frequency modes of ferric cytochrome c using vibrational coherence spectroscopy.
Investigations of the low frequency modes of ferric cytochrome c using vibrational coherence spectroscopy.
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DOI：
10.1021/jp501298c
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发表时间：
2014-06-12
期刊：
影响因子：
--
通讯作者：
Champion PM
中科院分区：
文献类型：
--
作者：
Karunakaran V;Sun Y;Benabbas A;Champion PM
飞秒振动相干光谱用于研究电子转移血红素蛋白细胞色素 c (cyt c) 的低频振动动力学。三价铁细胞色素 c 的振动相干光谱已被测量为索雷带内激发波长的函数。在 412 和 421 nm 之间激发获得的振动相干谱显示出~44 cm-1 处的强模式，该模式被认为对电子基态中的血红素波动运动有显着贡献。该分配部分基于 X 射线晶体结构的正常坐标结构分解 (NSD) 分析中存在大的血红素褶皱畸变。当激发波长移至~421-435 nm 区域时，瞬态吸收随着~55 和30 cm-1 附近两种模式的相对强度增加。当激光调谐到 443 nm 时，44 cm–1 附近的模式强度似乎在该区域最小化，然后恢复（但与蓝色激发相比具有相反的相位）。这些观察结果与 421-435 nm 区域内基态和激发态相干性的叠加一致，这是由于弱卟啉-铁电荷转移 (CT) 态的激发，其寿命足以观察振动相干性。接近 55 cm-1 的模式被认为是由瞬态 CT 状态下的褶皱引起的，由于其铁 d6 配置，该状态具有较少褶皱的血红素。
Femtosecond vibrational coherence spectroscopy is used to investigate the low frequency vibrational dynamics of the electron transfer heme protein, cytochrome c (cyt c). The vibrational coherence spectra of ferric cyt c have been measured as a function of excitation wavelength within the Soret band. Vibrational coherence spectra obtained with excitation between 412 and 421 nm display a strong mode at ∼44 cm–1 that has been assigned to have a significant contribution from heme ruffling motion in the electronic ground state. This assignment is based partially on the presence of a large heme ruffling distortion in the normal coordinate structural decomposition (NSD) analysis of the X-ray crystal structures. When the excitation wavelength is moved into the ∼421–435 nm region, the transient absorption increases along with the relative intensity of two modes near ∼55 and 30 cm–1. The intensity of the mode near 44 cm–1 appears to minimize in this region and then recover (but with an opposite phase compared to the blue excitation) when the laser is tuned to 443 nm. These observations are consistent with the superposition of both ground and excited state coherence in the 421–435 nm region due to the excitation of a weak porphyrin-to-iron charge transfer (CT) state, which has a lifetime long enough to observe vibrational coherence. The mode near 55 cm–1 is suggested to arise from ruffling in a transient CT state that has a less ruffled heme due to its iron d6 configuration.
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影响因子：
3.3
作者：
Karunakaran, Venugopal;Benabbas, Abdelkrim;Champion, Paul M.
通讯作者：
Champion, Paul M.
影响因子：
3.4
作者：
Gruia, Flaviu;Ye, Xiong;Champion, Paul M.
通讯作者：
Champion, Paul M.
影响因子：
--
作者：
ADAR, F;GOUTERMAN, M;ARONOWITZ, S
通讯作者：
ARONOWITZ, S
影响因子：
15
作者：
Gruia, Flaviu;Kubo, Minoru;Champion, Paul M.
通讯作者：
Champion, Paul M.
影响因子：
15
作者：
Kubo, Minoru;Gruia, Flaviu;Benabbas, Abdelkrim;Barabanschikov, Alexander;Montfort, William R.;Maes, Estelle M.;Champion, Paul M.
通讯作者：
Champion, Paul M.