The Phot LOV2 domain and its interaction with LOV1
The Phot LOV2 domain and its interaction with LOV1
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DOI：
10.1529/biophysj.104.058230
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发表时间：
2005-07-01
影响因子：
3.4
通讯作者：
Dick, B
中科院分区：
文献类型：
--
作者：
Guo, HM;Kottke, T;Dick, B
Phot蛋白是蓝光受体趋光蛋白的同系物。我们报告了一个比较研究的光周期的分离，光敏结构域LOV 1和LOV 2从莱茵衣藻phot蛋白，以及构建LOV 1/2包含这两个域。瞬态吸收测量揭示了短寿命的LOV 2-wt三重态（500 ns），但在突变体LOV 2-C250 S，其中反应性半胱氨酸被丝氨酸取代的三重态的长寿命（287 μ s）。相比之下，对于LOV 1，已经报道了LOV 1-wt中两种构象异构体的800 ns和4 ms的相应数值，以及LOV 1-C57 S的27 ms。混合畴LOV 1/2- wt、LOV 1/2-C57 S和LOV 1/2-C250 S中的三重态衰减动力学可以作为相应单畴行为的叠加来分析。对于光加合物回到深色形式的缓慢热反应，情况不同。虽然单个结构域LOV 1和LOV 2显示两个衰变分量，但双结构域LOV 1/2-C57 S和LOV 1/2-C250 S都仅显示单个分量。因此，这两个域的相互作用在三重态的寿命期间不会表现出来，但会改变加合态的衰变行为。
Phot proteins are homologs of the blue-light receptor phototropin. We report a comparative study of the photocycles of the isolated, light-sensitive domains LOV1 and LOV2 from Chlamydomonas reinhardtii phot protein, as well as the construct LOV1/2 containing both domains. Transient absorption measurements revealed a short lifetime of the LOV2-wt triplet state (500 ns), but a long lifetime (287 mu s) of the triplet in the mutant LOV2-C250S, in which the reactive cysteine is replaced by serine. For LOV1, in comparison, corresponding numbers of 800 ns and 4 ms for the two conformers in LOV1-wt, and 27 ms for LOV1-C57S have been reported. The triplet decay kinetics in the mixed domains LOV1/2- wt, LOV1/2-C57S, and LOV1/2-C250S can be analyzed as the superposition of the behavior of the corresponding single domains. The situation is different for the slow, thermal reaction of the photoadduct back to the dark form. Whereas the individual domains LOV1 and LOV2 show two decay components, the double domains LOV1/2-C57S and LOV1/2-C250S both show only a single component. The interaction of the two domains does therefore not manifest itself during the lifetime of the triplet states, but changes the decay behavior of the adduct states.