Frankfurt Institute for Advanced Studies, Goethe University, Frankfurt am Main, Germany.
Biophys J. 2010 Jul 7;99(1):40-9. doi: 10.1016/j.bpj.2010.03.053.
The magnetic compass of birds is embedded in the visual system and it has been hypothesized that the primary sensory mechanism is based on a radical pair reaction. Previous models of magnetoreception have assumed that the radical pair-forming molecules are rigidly fixed in space, and this assumption has been a major objection to the suggested hypothesis. In this article, we investigate theoretically how much disorder is permitted for the radical pair-forming, protein-based magnetic compass in the eye to remain functional. Our study shows that only one rotational degree of freedom of the radical pair-forming protein needs to be partially constrained, while the other two rotational degrees of freedom do not impact the magnetoreceptive properties of the protein. The result implies that any membrane-associated protein is sufficiently restricted in its motion to function as a radical pair-based magnetoreceptor. We relate our theoretical findings to the cryptochromes, currently considered the likeliest candidate to furnish radical pair-based magnetoreception.
鸟类的磁罗盘嵌入在视觉系统中，有人假设主要的感觉机制基于自由基对反应。以前的磁受体模型假设形成自由基对的分子在空间中是刚性固定的，这一假设一直是对所提出的假设的主要反对意见。在本文中，我们从理论上研究了在眼睛中形成自由基对的蛋白质的磁罗盘允许有多少无序仍能保持其功能。我们的研究表明，形成自由基对的蛋白质只需要部分约束一个旋转自由度，而另外两个旋转自由度不会影响蛋白质的磁感受特性。这一结果意味着任何与膜相关的蛋白质在其运动中都受到足够的限制，足以作为基于自由基对的磁受体发挥作用。我们将我们的理论发现与隐花色素联系起来，隐花色素目前被认为是提供基于自由基对的磁受体的最有可能的候选者。
