Dong Chao, Yang Jing, Leimkühler Silke, Kirk Martin L
Department of Chemistry and Chemical Biology, The University of New Mexico , MSC03 2060, 1 University of New Mexico, Albuquerque, New Mexico 87131-0001, United States.
Inorg Chem. 2014 Jul 21;53(14):7077-9. doi: 10.1021/ic500873y. Epub 2014 Jun 30.
The reducing substrates 4-thiolumazine and 2,4-dithiolumazine have been used to form Mo(IV)-product complexes with xanthine oxidase (XO) and xanthine dehydrogenase. These Mo(IV)-product complexes display an intense metal-to-ligand charge-transfer (MLCT) band in the near-infrared region of the spectrum. Optical pumping into this MLCT band yields resonance Raman spectra of the Mo site that are devoid of contributions from the highly absorbing FAD and 2Fe2S clusters in the protein. The resonance Raman spectra reveal in-plane bending modes of the bound product and low-frequency molybdenum dithiolene and pyranopterin dithiolene vibrational modes. This work provides keen insight into the role of the pyranopterin dithiolene in electron-transfer reactivity.
还原底物4-硫代鲁马嗪和2,4-二硫代鲁马嗪已被用于与黄嘌呤氧化酶（XO）和黄嘌呤脱氢酶形成钼（IV）-产物复合物。这些钼（IV）-产物复合物在光谱的近红外区域显示出强烈的金属-配体电荷转移（MLCT）带。光泵浦到这个MLCT带中会产生钼位点的共振拉曼光谱，该光谱没有蛋白质中高吸收性的黄素腺嘌呤二核苷酸（FAD）和2Fe2S簇的贡献。共振拉曼光谱揭示了结合产物的面内弯曲模式以及低频的钼二硫烯和吡喃蝶呤二硫烯振动模式。这项工作为吡喃蝶呤二硫烯在电子转移反应中的作用提供了深刻的见解。
