Reactive cysteine is protonated in the triplet excited state of the LOV2 domain in Adiantum phytochrome3
Reactive cysteine is protonated in the triplet excited state of the LOV2 domain in Adiantum phytochrome3
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DOI：
10.1021/ja0436897
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发表时间：
2005-02-02
影响因子：
15
通讯作者：
Kandori, H
中科院分区：
文献类型：
--
作者：
Sato, Y;Iwata, T;Kandori, H
向光素是一种植物蓝光传感蛋白，在LOV结构域中具有黄素单核苷酸（FMN）作为发色团。它的光反应是FMN和附近的半胱氨酸在FMN的三重激发态下形成加合物。在本通讯中，我们揭示了活性半胱氨酸是质子化的三重激发态的LOV2域ofAdiantum光敏色素3通过低温FTIR光谱。它的氢键相互作用在三重激发态得到加强，推测与FMN发色团。这种强相互作用在微秒时间尺度上驱动加合物形成。
Phototropin is a plant blue-light sensor protein that possesses a flavin mononucleotide (FMN) as the chromophore in LOV domains. Its photoreaction is an adduct formation between FMN and a nearby cysteine that takes place in the triplet excited state of FMN. In this communication, we revealed that the reactive cysteine is protonated in the triplet excited state of the LOV2 domain ofAdiantumphytochrome3 by means of low-temperature FTIR spectroscopy. Its hydrogen-bonding interaction is strengthened in the triplet excited state, presumably with the FMN chromophore. Such strong interaction drives adduct formation on a microsecond time scale.