细菌传感的合作模型
Cooperative Model of Bacterial Sensing
摘要：
细菌的趋化性是由一组受体的信号传导控制的。提出了一个合作模型，其中相邻的受体二聚体之间的耦合增强了敏感性，刺激可以被检测到，而不会减少趋化性可以操作的化学效应浓度的范围。单个受体二聚体具有两种稳定的构象状态：一种是活性的，一种是非活性的。噪声引起这些状态之间的分布，受配体结合的概率，也由相邻受体二聚体的构象状态。基于与随机分布磁场中伊辛模型的等价性，求解了两态模型。该模型只有两个有效参数，并统一了一些实验结果。根据比较耦合和噪声的参数的值，信号可以对与配体结合的受体二聚体的分数的变化任意敏感。甲基化水平变化的抵消作用映射到伊辛模型中的诱导场。通过将活性返回到刺激前水平，这使受体簇适应化学效应物的新的环境浓度，并确保可以在宽范围的浓度下保持敏感的反应。
英文摘要：
Bacterial chemotaxis is controlled by the signalling of a cluster of receptors. A cooperative model is presented, in which coupling between neighbouring receptor dimers enhances the sensitivity with which stimuli can be detected, without diminishing the range of chemoeffector concentration over which chemotaxis can operate. Individual receptor dimers have two stable conformational states: one active, one inactive. Noise gives rise to a distribution between these states, with the probability influenced by ligand binding, and also by the conformational states of adjacent receptor dimers. The two-state model is solved, based on an equivalence with the Ising model in a randomly distributed magnetic field. The model has only two effective parameters, and unifies a number of experimental findings. According to the value of the parameter comparing coupling and noise, the signal can be arbitrarily sensitive to changes in the fraction of receptor dimers to which ligand is bound. The counteracting effect of a change of methylation level is mapped to an induced field in the Ising model. By returning the activity to the pre-stimulus level, this adapts the receptor cluster to a new ambient concentration of chemoeffector and ensures that a sensitive response can be maintained over a wide range of concentrations.
机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。
