Müller Johannes, Kuttler Christina, Hense Burkhard A
Technical University Munich, Centre for Mathematical Sciences, Boltzmannstr. 3, D-85748 Garching, Munich,
Biosystems. 2008 Apr;92(1):76-81. doi: 10.1016/j.biosystems.2007.12.004. Epub 2007 Dec 25.
Autoinducer sensing, also known as quorum sensing, is the communication of bacteria by autoinducer (small signaling molecules). Cells respond on extremely low concentrations of autoinducer: only one or two molecules per cell are sufficient. At this signal level a high degree of noise is inherent. We ask for the mechanism that is able to overcome the stochasticity of the signal. By means of a model and parameter fitting we show that the sensing module acts as a low pass filter, representing the biochemical equivalent of a moving average. It is shown that the system works most sensitive in the range of 0-50 nM autoinducer. Moreover, the time scale of the reaction depends on the signal strength in a crucial manner. Nonlinear feedback is able to further enhance the sensitivity. The biological implications of the low pass filter property are discussed.
自诱导物感应，也称为群体感应，是细菌通过自诱导物（小信号分子）进行的通讯。细胞对极低浓度的自诱导物做出反应：每个细胞仅一两个分子就足够了。在这个信号水平上，高度的噪声是固有的。我们探究能够克服信号随机性的机制。通过模型和参数拟合，我们表明感应模块起到低通滤波器的作用，代表移动平均值的生化等效物。结果表明，该系统在0 - 50 nM自诱导物范围内工作最为敏感。此外，反应的时间尺度以关键方式取决于信号强度。非线性反馈能够进一步提高灵敏度。我们讨论了低通滤波器特性的生物学意义。
