Chemical amplification of magnetic field effects relevant to avian magnetoreception
Chemical amplification of magnetic field effects relevant to avian magnetoreception
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DOI：
10.1038/nchem.2447
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发表时间：
2016-04-01
期刊：
影响因子：
21.8
通讯作者：
Hore, P. J.
中科院分区：
文献类型：
--
作者：
Kattnig, Daniel R.;Evans, Emrys W.;Hore, P. J.
像地球一样弱的磁场可以改变自由基对反应的产率，即使所涉及的能量比室温下的热能k（B）T小几个数量级。自由基对机制被认为是候鸟依赖光的磁罗盘的来源，它在视网膜的隐花色素黄素蛋白中起作用。在这里，我们证明了初级磁场对黄素光反应的影响可以通过连续光激发条件下的缓慢自由基终止反应来化学放大。放大的性质和起源的研究揭示了分子间的黄素-色氨酸和黄素-抗坏血酸光循环和密切相关的分子内黄素-色氨酸自由基对隐花色素。放大因子高达5.6，观察到磁场弱于1 mT。大量的化学放大可能会对隐花色素基磁罗盘传感器的可行性产生重大影响。
Magnetic fields as weak as the Earth's can change the yields of radical pair reactions even though the energies involved are orders of magnitude smaller than the thermal energy, k(B)T, at room temperature. Proposed as the source of the light-dependent magnetic compass in migratory birds, the radical pair mechanism is thought to operate in cryptochrome flavoproteins in the retina. Here we demonstrate that the primary magnetic field effect on flavin photoreactions can be amplified chemically by slow radical termination reactions under conditions of continuous photoexcitation. The nature and origin of the amplification are revealed by studies of the intermolecular flavin-tryptophan and flavin-ascorbic acid photocycles and the closely related intramolecular flavin-tryptophan radical pair in cryptochrome. Amplification factors of up to 5.6 were observed for magnetic fields weaker than 1 mT. Substantial chemical amplification could have a significant impact on the viability of a cryptochrome-based magnetic compass sensor.