Spin dynamics of reactive oxygen species as studied by probing electron spin polarization

通过探测电子自旋极化研究活性氧的自旋动力学

• 批准号: 15550005
• 负责人: KAWAI Akio
• 金额: $ 2.43万
• 依托单位: Tokyo Institute of Technology
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 2003
• 资助国家: 日本
• 起止时间: 2003 至 2005
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-15550005/
• 关键词: singlet oxygen molecule; pulsed ESR; time-resolved ESR; excited state quenching; reactive oxygen species; CIDEP; electron spin polarization; nitroxide radical; 電子スピン分極; 励起状態; アルブミン; ラジカル; FT-ESR

Electron spin polarization created in various systems of O_2(^1Δ_g) and radicals were observed by means of the time-resolved ESR (TR-ESR) spectroscopy. Electron spin polarization of TEMPO and PTIO radicals are 340 and 140 while those of galvinoxyl, DPPH and verdazyl radicals are 0.7, 0 and 0 in the unit of Boltzmann polarization. This result indicate that electron spin polarization is very efficiently created in TEMPO and PTIO while is not in galvinoxyl, DPPH and verdazyl radicals. According to the theoretical analysis of electron spin polarization, it was found that the efficiency of spin polarization creation is due to the magnitude of electron exchange interaction between O_2(^1Δ_g) and radical which is largely controlled by the size of SOMO orbital of radical.Electron spin polarization creation was also examined on the surface of α-lactalbumin as an representative of protein molecules. Selective photoexcitation of tryptophan residue in α-lactalbumin followed by the deactivation due to TEMPO radical dissolved in the sample solution results in strong electron spin polarization of TEMPO which was monitored by pulsed ESR method. This experiments clearly demonstrated that the spin polarization created on the surface of protein molecules can be monitored by TR-ESR method and promised that O_2(^1Δ_g) diffusion and deactivation process on protein surface can be monitored by spin probing method in the future.

用时间分辨电子自旋共振（TR-ESR）谱观察了O_2（^1Δ_g）和自由基体系中产生的电子自旋极化。克里思和PTIO自由基的电子自旋极化率分别为340和140，Galvinoxyl、DPPH和Verdazyl自由基的电子自旋极化率分别为0.7、0和0。这一结果表明，电子自旋极化是非常有效地创建克里思和PTIO，而不是galvinoxyl，DPPH和verdazyl自由基。通过对电子自旋极化的理论分析，发现电子自旋极化产生的效率取决于O_2（^1Δ g）与自由基之间电子交换作用的大小，而自由基的自组织轨道（SOMO）的大小在很大程度上决定了电子自旋极化产生的效率。α-乳清蛋白中色氨酸残基的选择性光激发和溶解在样品溶液中的克里思自由基的失活导致克里思的强电子自旋极化，用脉冲ESR方法监测到这种现象。实验结果表明，利用TR-ESR方法可以监测蛋白质分子表面的自旋极化过程，并为将来利用自旋探针方法监测蛋白质表面O_2（^1Δ g）扩散和失活过程提供了可能。

项目成果

Masaaki Mitsui, Keizo Takeda, Yasuhiro Kobori, Akio Kawai, Kinichi Obi: "Unusually large dynamic electron polarization in an O_2(^1Δ_g)-2,2,6,6-tetramethylpiperidine-1-oxyl radical system"Journal of Physical Chemistry A. 108. 1120-1126 (2004)

Masaaki Mitsui、Keizo Takeda、Yasuhiro Kobori、Akio Kawai、Kinichi Obi：“O_2(^1Δ_g)-2,2,6,6-tetramethylpiperidine-1-oxyl自由基体系中异常大的动态电子极化”Journal of Physical Chemistry A . 108. 1120-1126 (2004)

Lifetime mesurements of singlet oxygen molecule (^1Δ_g) by a time-resolved ESR spectroscopy

通过时间分辨 ESR 光谱法测量单线态氧分子 (^1Δ_g) 的寿命

• 发表时间: 2006
• 期刊: Journal of the spectroscopical society of JAPAN Vol.55(in press)
• 作者: Masashi Tsuge;Akio Kawai;Hajime Terazono;河合 明雄;Akio Kawai;Hajime Terazono;Akio Kawai
• 通讯作者: Akio Kawai

Quenching mechanism of excited coronene by a nitroxide radical studied by probing dynamic electron polarization

动态电子极化研究硝基氧自由基激发晕苯的猝灭机理

• 发表时间: 2004
• 期刊: Journal of Physical Chemistry A 108
• 作者: Akio Kawai;Takehiro Hidemori;Kazuhiko Shibuya;Akio Kawai;Masaaki Mitsui;Masaaki Mitsui
• 通讯作者: Masaaki Mitsui

Jet spectroscopy of arylmethyl radicals in the visible region: assignment of low-frequency vibrational modes in diphenylmethyl and chlorodiphenylmethyl radicals

可见光区域芳甲基自由基的喷射光谱：二苯甲基和氯二苯甲基自由基低频振动模式的分配

• 发表时间: 2006
• 期刊: Chem. Chem. Phys. 8
• 作者: M. Tsuge;S. Hamatani;A. Kawai;K. Tsuji;K. Shibuya Phys.
• 通讯作者: K. Shibuya Phys.

Quenching mechanism of excited coronene by a nitroxide radical studied by probing

氮氧自由基激发晕苯的猝灭机理的探究

• 发表时间: 2004
• 期刊: Journal of Physical Chemistry A 108
• 作者: Masaaki Mitsui;Yasuhiro Kobori;Akio Kawai;Kinichi Obi
• 通讯作者: Kinichi Obi