Department of Applied Mathematics, University of Washington, Seattle, Washington, USA.
Biophys J. 2010 Jan 6;98(1):1-11. doi: 10.1016/j.bpj.2009.09.055.
Bistability is a nonlinear phenomenon widely observed in nature including in biochemical reaction networks. Deterministic chemical kinetics studied in the past has shown that bistability occurs in systems with strong (cubic) nonlinearity. For certain mesoscopic, weakly nonlinear (quadratic) biochemical reaction systems in a small volume, however, stochasticity can induce bistability and bifurcation that have no macroscopic counterpart. We report the simplest yet known reactions involving driven phosphorylation-dephosphorylation cycle kinetics with autocatalytic kinase. We show that the noise-induced phenomenon is correlated with free energy dissipation and thus conforms with the open-chemical system theory. A previous reported noise-induced bistability in futile cycles is found to have originated from the kinase synchronization in a bistable system with slow transitions, as reported here.
双稳性是一种在自然界中广泛观察到的非线性现象，包括在生化反应网络中。过去研究的确定性化学动力学表明，双稳性发生在具有强（立方）非线性的系统中。然而，对于在小体积中某些介观的、弱非线性（二次）生化反应系统，随机因素可以诱导没有宏观对应物的双稳性和分岔。我们报告了最简单但已知的涉及驱动磷酸化-去磷酸化循环动力学的反应，其中包含自催化激酶。我们表明，噪声诱导的现象与自由能耗散有关，因此符合开放化学系统理论。以前报道的无效循环中噪声诱导的双稳性被发现源自于双稳系统中激酶的同步化，该双稳系统具有缓慢的转变，如本文所报道的。
