Comparison between ultrafast fluorescence dynamics of FMN binding protein from Desulfovibrio vulgaris, strain miyazaki, in solution vs crystal phases
Comparison between ultrafast fluorescence dynamics of FMN binding protein from Desulfovibrio vulgaris, strain miyazaki, in solution vs crystal phases
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DOI：
10.1021/jp073702k
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发表时间：
2007-08-02
影响因子：
3.3
通讯作者：
Kitamura, Masaya
中科院分区：
文献类型：
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作者：
Chosrowjan, Haik;Taniguchi, Seiji;Kitamura, Masaya
比较了普通脱硫菌Miyaxaki F株FMN结合蛋白在溶液和晶体中的超快荧光动力学。溶液中的荧光寿命为167 fs（96%）和1.5 ps（4%）（tau（av）= 220 fs），晶体中的荧光寿命为730 fs（60%）和大于10 ps（40%）（tau（av）= 4.44 ps）。蛋白质中黄素的荧光猝灭被认为是由于光诱导电子转移（ET）从色氨酸或酪氨酸附近的激发异咯嗪（ISO）。晶体中的平均寿命是溶液中的20倍。Iso与附近的Trp-32、Tyr-35和Trp-106之间的平均距离在溶液中分别为8.42、7.36和8.15 A（通过NMR光谱获得），在晶体中分别为7.05、7.72和8.49 A（通过X射线晶体学获得）。晶体中寿命的延长不能用状态间距离的变化来解释。这可能是由于FBP周围没有水分子，运动自由度高，这可能是黄素蛋白中ET的驱动力。
Ultrafast fluorescence dynamics of FMN binding protein (FBP) from Desulfobivrio vulgaris, strain Miyaxaki F, were compared in solution and crystal phases. Fluorescence lifetimes of FBP were 167 fs (96%) and 1.5 ps (4%) in solution (tau(av) = 220 fs), and 730 fs (60%) and longer than 10 ps (40%) in crystals (tau(av) = 4.44 ps). The quenching of the fluorescence of flavin in the protein was considered to be due to photoinduced electron transfer (ET) from Trp or Tyr to the excited isoalloxazine (Iso) nearby. The average lifetime was 20 times longer in crystal vs in solution. Averaged distances between Iso and nearby Trp-32, Tyr-35, and Trp-106 were 8.42, 7.36, and 8.15 A in solution, respectively (obtained by NMR spectroscopy), and 7.05, 7.72, and 8.49 A in crystal, respectively (obtained by X-ray crystallography). The prolonged lifetime in crystal cannot be elucidated by the change in the distances between the states. It was suggested that the longer lifetime in crystal was ascribed to the absence of water molecules around FBP with rapid motional freedom, which may be the driving force for the ET in flavoproteins.