Ultrafast Dynamics of Fatty Acid Photodecarboxylase in Anionic Semiquinone State.
Ultrafast Dynamics of Fatty Acid Photodecarboxylase in Anionic Semiquinone State.
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DOI：
10.1021/acs.jpclett.2c02183
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发表时间：
2022-11
期刊：
影响因子：
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通讯作者：
Ruiqin Wu;Chao Yang;Lijuan Wang;D. Zhong
中科院分区：
文献类型：
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作者：
Ruiqin Wu;Chao Yang;Lijuan Wang;D. Zhong
脂肪酸光脱羧酶是一种新发现的蓝光驱动的催化脂肪酸脱羧的光酶。该催化反应涉及一个瞬时的阴离子半醌黄素辅因子（FAD·-）作为中间体，但这种阴离子自由基的光化学性质在很大程度上是未知的。在这里，我们在厌氧条件下产生了FAD·-状态的野生型FAP，并进行了飞秒分辨荧光和吸收测量。我们已经观察到的多相失活动力学的激发态在多个时间尺度上从几皮秒，甚至几纳秒，通过各种电子状态之间的锥形交叉点。有趣的是，纳秒分量只能从更高的电子激发态观察到。我们的结果显示了各种激发态的能量景观的复杂性，并排除了电子或质子转移与附近的残基（S）在活性中心的发生。
Fatty acid photodecarboxylase is a newly identified blue-light driven photoenzyme that catalyzes decarboxylation of fatty acids. The catalytic reaction involves a transient anionic semiquinone of flavin cofactor (FAD•-) as an intermediate, but photochemical properties of this anionic radical are largely unknown. Here, we have anaerobically produced the wild-type FAP in the FAD•- state and conducted femtosecond-resolved fluorescence and absorption measurements. We have observed the multiphasic deactivation dynamics of excited states on multiple time scales from a few picoseconds even to a few nanoseconds through conical intersections between various electronic states. Interestingly, the nanosecond components can only be observed from higher electronic excited states. Our results show the complexity of the energy landscapes of various excited states and rule out the occurrence of electron or proton transfer with nearby residue(s) in the active site.