Color regulation and stabilization of chromophore by Cys69 in photoactive yellow protein active center
作者:Kentaro Okamoto、Norio Hamada、Taka-aki Okamura、Norikazu Ueyama、Hitoshi Yamamoto
DOI:10.1039/b905835d
日期:——
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 NH⋯OC hydrogen bond to the conjugated carbonyl oxygen and thioester linkage of the chromophore. The results of UV-vis and 13C 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色素的模型化合物,以研究Cys69残基在活性中心中的作用,该残基与共轭羰基氧和色素硫酯键形成分子内NH⋯OC氢键。模型化合物的UV-vis和13C NMR光谱结果表明,它们使色素的负电荷发生离域,并增强了酚酸阴离子状态中类醌共振结构的贡献。因此,Cys69残基在活性中心中对色彩的调节和色素阴离子的稳定性起着重要作用。