Differences between Protein Dynamics of Hemoglobin upon Dissociation of Oxygen and Carbon Monoxide
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- 作者：Yuka Murakawa ; Masako Nagai ; Yasuhisa Mizutani
- 刊名：The Journal of the American Chemical Society
- 出版年：2012
- 出版时间：January 25, 2012
- 年：2012
- 卷：134
- 期：3
- 页码：1434-1437
- 全文大小：275K
- 年卷期：v.134,no.3(January 25, 2012)
- ISSN：1520-5126
文摘
Protein dynamics of human adult hemoglobin (HbA) upon ligand photolysis of oxygen (O2) and carbon monoxide (CO) was investigated using time-resolved resonance Raman (TR3) spectroscopy. The TR3 spectra of the both photoproducts at 1-ns delay differed from that of the equilibrium deligated form (deoxy form) in the frequencies of the iron鈥揾istidine stretching [谓(Fe鈥揌is)] and methine wagging (纬7) modes, and the band intensity of pyrrole stretching and substituent bending (谓8) modes. Spectral changes of the O2 photoproduct in the submicrosecond region were faster than those of the CO photoproduct, indicating that the structural dynamics following the photodissociation is ligand dependent for HbA. In contrast, no ligand dependence of the dynamics was observed for myoglobin, which has a structure similar to that of the subunit of HbA. The structural dynamics and relevance to the functionality of HbA also are discussed.