Okamoto Kentaro, Hamada Norio, Okamura Taka-aki, Ueyama Norikazu, Yamamoto Hitoshi
Department of Macromolecular Science, Graduate School of Science, Osaka University, Machikaneyama-cho 1-1, Toyonaka, Osaka 560-0043, Japan.
Org Biomol Chem. 2009 Sep 21;7(18):3782-91. doi: 10.1039/b905835d. Epub 2009 Jul 15.
Model compounds of PYP chromophore were synthesized and characterized to investigate the role of the Cys69 residue in the active center, which has the intramolecular NHOC hydrogen bond to the conjugated carbonyl oxygen and thioester linkage of the chromophore. The results of UV-vis and (13)C NMR spectroscopy of the model compounds indicated that they delocalized the negative charge of the chromophore and increased the contribution of the quinoid-like resonance structure in the phenolate anion state. Thus, the Cys69 residue plays an important role in the regulation of the color and the stabilization of the chromophore anion in the active center.
合成并表征了PYP发色团的模型化合物，以研究活性中心中Cys69残基的作用，该残基与发色团的共轭羰基氧和硫酯键具有分子内NHOC氢键。模型化合物的紫外可见光谱和(13)C NMR光谱结果表明，它们使发色团的负电荷离域，并增加了酚盐阴离子状态下类醌共振结构的贡献。因此，Cys69残基在活性中心发色团阴离子的颜色调节和稳定性方面起着重要作用。
