Modeling magnetosensitive ion channels in the viscoelastic environment of living cells.
Modeling magnetosensitive ion channels in the viscoelastic environment of living cells.
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模拟活细胞粘弹性环境中的磁敏离子通道
DOI：
10.1103/physreve.92.042711
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发表时间：
2015
期刊：
影响因子：
--
通讯作者：
Goychuk
中科院分区：
文献类型：
--
作者：
Goychuk
我们提出并研究了一个假设的磁敏离子通道模型，该模型长期以来被认为是解释弱磁场对生物体的影响的可能候选者，从趋磁细菌到鱼类，鸟类，大鼠，蝙蝠和其他哺乳动物，包括人类。该模型的核心是由磁小体作为传感器的短链提供的，该磁小体通过弹性连接器耦合到离子通道的门控元件，从而在细胞膜中形成小簇。磁传感器的一端固定在附着于膜的细胞骨架元件上，并暴露于粘弹性胞质溶胶。它的自由端可以响应外磁场的变化而在粘弹性细胞质中随机和亚扩散地重新定向，并可以打开耦合离子通道的门。传感器的动态特性通常是不稳定的，这是由于门的双稳态，它可以处于两种状态，其概率取决于传感器的方向。对于现实的参数，它示出，该模型通道可以在地球的磁场中操作的一个小的数量（五至七）的单域磁小体构成的传感器棒，其中每个具有典型的大小中发现的趋磁细菌和其他生物体，甚至只是一个足够大的纳米粒子的特征尺寸也发现在自然界中。结果表明，由于介质的粘弹性，在其开放和关闭状态下的通道的停留时间的阻尼动力学一般表现出幂律和拉伸指数分布。这提供了一个通用的物理机制，用于解释这种异常动力学的起源，为其他离子通道的传感器移动在一个粘弹性的环境中提供的细胞质或生物膜，在一个相当普遍的情况下，超出了迷人的假设磁敏离子通道，我们探索。
We propose and study a model of hypothetical magnetosensitive ionic channels which are long thought to be a possible candidate to explain the influence of weak magnetic fields on living organisms ranging from magnetotactic bacteria to fishes, birds, rats, bats, and other mammals including humans. The core of the model is provided by a short chain of magnetosomes serving as a sensor, which is coupled by elastic linkers to the gating elements of ion channels forming a small cluster in the cell membrane. The magnetic sensor is fixed by one end on cytoskeleton elements attached to the membrane and is exposed to viscoelastic cytosol. Its free end can reorient stochastically and subdiffusively in viscoelastic cytosol responding to external magnetic field changes and can open the gates of coupled ion channels. The sensor dynamics is generally bistable due to bistability of the gates which can be in two states with probabilities which depend on the sensor orientation. For realistic parameters, it is shown that this model channel can operate in the magnetic field of Earth for a small number (five to seven) of single-domain magnetosomes constituting the sensor rod, each of which has a typical size found in magnetotactic bacteria and other organisms or even just one sufficiently large nanoparticle of a characteristic size also found in nature. It is shown that, due to the viscoelasticity of the medium, the bistable gating dynamics generally exhibits power law and stretched exponential distributions of the residence times of the channels in their open and closed states. This provides a generic physical mechanism for the explanation of the origin of such anomalous kinetics for other ionic channels whose sensors move in a viscoelastic environment provided by either cytosol or biological membrane, in a quite general context, beyond the fascinating hypothesis of magnetosensitive ionic channels we explore.
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影响因子：
3.3
作者：
Santamaria-Holek, I.;Rubi, J. M.;Gadomski, A.
通讯作者：
Gadomski, A.
关于非马尔可夫过程的时间演化的注解
影响因子：
1.6
作者：
P. Hänggi;H. Thomas;H. Grabert;P. Talkner
通讯作者：
P. Talkner
鸟类中可能存在磁传感器。
影响因子：
2
作者：
E. Yorke
通讯作者：
E. Yorke
影响因子：
2.4
作者：
Kharchenko, Vasyl O.;Goychuk, Igor
通讯作者：
Goychuk, Igor
DOI：
10.1209/epl/i2004-10525-6
发表时间：
2005-06-01
期刊：
EUROPHYSICS LETTERS
影响因子：
--
作者：
Binhi, VN;Chernavskii, DS
通讯作者：
Chernavskii, DS