Picobiology Institute, Department of Life Science, Graduate School of Life Science, University of Hyogo, Koto 3-2-1, Kamigori-cho, Ako-gun, Hyogo, 678-1297, Japan.
J Bioenerg Biomembr. 2010 Jun;42(3):241-3. doi: 10.1007/s10863-010-9282-y. Epub 2010 Apr 1.
In the resting oxidized state (the fully oxidized "as-isolated" state) of cytochrome c oxidase (CcO) preparation, a resonance Raman band is observed at 755 cm(-1) upon 647.1 nm excitation in resonance with an absorption band at 655 nm. Addition of cyanide eliminates the Raman band concomitant with loss of the absorption band at 655 nm. These results strongly suggest that the Raman band at 755 cm(-1) originates from the O-O stretching mode of the bridging peroxide (Fe-O(-)-O(-)-Cu) in the O(2) reduction site of the fully oxidized "as-isolated" CcO. Although the peroxide bridged structure has been proposed on the basis of X-ray crystallography and reductive titration experiments, the present vibrational spectroscopic analyses reveal conclusively the chemical nature of the bridging ligand at the O(2) reduction site of the fully oxidized "as-isolated" bovine heart CcO.
在细胞色素 c 氧化酶 (CcO) 制剂的静息氧化状态（完全氧化的“原样”状态）下，在 647.1nm 激发下，与 655nm 处的吸收带共振时，观察到 755cm(-1)处的共振拉曼带。氰化物的加入消除了与 655nm 处吸收带同时损失的拉曼带。这些结果强烈表明，755cm(-1)处的拉曼带源自完全氧化的“原样”CcO 的 O2 还原部位中桥接过氧物（Fe-O(-)-O(-)-Cu）的 O-O 伸缩模式。尽管基于 X 射线晶体学和还原滴定实验已经提出了过氧化物桥接结构，但目前的振动光谱分析明确揭示了完全氧化的“原样”牛心 CcO 的 O2 还原部位的桥接配体的化学性质。
