Qian Hong, Reluga Timothy C
Department of Applied Mathematics, University of Washington, Seattle, Washington 98195, USA.
Phys Rev Lett. 2005 Jan 21;94(2):028101. doi: 10.1103/PhysRevLett.94.028101. Epub 2005 Jan 18.
We develop a rigorous nonequilibrium thermodynamics for an open system of nonlinear biochemical reactions responsible for cell signal processing. We show that the quality of the biological switch consisting of a phosphorylation-dephosphorylation cycle, such as those in protein kinase cascade, is controlled by the available intracellular free energy from the adenosine triphosphate (ATP) hydrolysis in vivo: DeltaG=k(B)Tln(([ATP]/K(eq)[ADP]), where K(eq) is the equilibrium constant. The model reveals the correlation between the performance of the switch and the level of DeltaG. The result demonstrates the importance of nonequilibrium thermodynamics in analyzing biological information processing, provides its energetic cost, establishes an interplay between signal transduction and energy metabolism in cells, and suggests a biological function for phosphoenergetics in the ubiquitous phosphorylation signaling.
我们为负责细胞信号处理的非线性生化反应开放系统开发了一种严格的非平衡热力学。我们表明，由磷酸化-去磷酸化循环组成的生物开关的质量，例如蛋白激酶级联反应中的那些，在体内由三磷酸腺苷（ATP）水解产生的可用细胞内自由能控制：ΔG = k(B)Tln(([ATP]/K(eq)[ADP])，其中K(eq)是平衡常数。该模型揭示了开关性能与ΔG水平之间的相关性。结果证明了非平衡热力学在分析生物信息处理中的重要性，提供了其能量成本，建立了细胞中信号转导与能量代谢之间的相互作用，并暗示了磷酸能量学在普遍存在的磷酸化信号传导中的生物学功能。
