The Chemical Master Equation Approach to Open Biochemical Systems:Nonlinear Stochastic Dynamics and Nonequilibrium Statistical Thermodynamics
报告人:
Hong Qian 钱竑
University of Washington 教授
报告时间:
2010-07-22 16:00
报告地点:
清华大学科学馆104报告厅
主办单位:
清华大学周培源应用数学研究中心
简介:
I present the stochastic, chemical master equation as a unifying Approach to the dynamics of biochemical reaction systems in a mesoscopic volume under a living environment. A living environment provides a continuous chemical energy input that sustains the reaction system in a nonequilibrium steady state with concentration fluctuations. We discuss nonlinear biochemical reaction systems such as phosphorylation-dephosphorylation cycle (PdPC) with bistability.Emphasis is paid to the comparison between the stochastic dynamics and the prediction based on the traditional approach based on the Law of Mass Action. We introduce the dirence between nonlinear bistability and stochastic bistability, the latter has no deterministic counterpart. For systems with nonlinear bistability, there are three dirent time scales: (a) individual biochemical reactions, (b) nonlinear network dynamics approaching to attractors, and (c) cellular evolution. For mesoscopic systems with size of a living cell, dynamics in (a) and (c) are stochastic while that with (b) is dominantly deterministic. Both (b) and (c) are emergent properties of a dynamic biochemical network; We suggest that the (c) is most relevant to major cellular biochemical processes such as epigenetic regulation, apoptosis, and cancer immunoediting. The cellular evolution proceeds with transitions among the attractors of (b) in a "punctuated equilibrium" manner.
