ETH Zurich, Zurich, Switzerland.
Biophys J. 2010 Nov 17;99(10):3139-44. doi: 10.1016/j.bpj.2010.09.043.
Thermodynamic analysis of metabolic networks has recently generated increasing interest for its ability to add constraints on metabolic network operation, and to combine metabolic fluxes and metabolite measurements in a mechanistic manner. Concepts for the calculation of the change in Gibbs energy of biochemical reactions have long been established. However, a concept for incorporation of cross-membrane transport in these calculations is still missing, although the theory for calculating thermodynamic properties of transport processes is long known. Here, we have developed two equivalent equations to calculate the change in Gibbs energy of combined transport and reaction processes based on two different ways of treating biochemical thermodynamics. We illustrate the need for these equations by showing that in some cases there is a significant difference between the proposed correct calculation and using an approximative method. With the developed equations, thermodynamic analysis of metabolic networks spanning over multiple physical compartments can now be correctly described.
代谢网络的热力学分析最近引起了越来越多的关注，因为它能够对代谢网络的运作施加约束，并以一种机械的方式将代谢通量和代谢物测量值结合起来。计算生化反应吉布斯自由能变化的概念早已确立。然而，在这些计算中纳入跨膜运输的概念仍然缺失，尽管运输过程热力学性质的计算理论早已为人所知。在这里，我们基于两种不同的处理生化热力学的方法，开发了两个等效的方程来计算组合运输和反应过程的吉布斯自由能变化。我们通过表明在某些情况下，拟议的正确计算和使用近似方法之间存在显著差异，说明了这些方程的必要性。通过开发的方程，现在可以正确描述跨越多个物理隔室的代谢网络的热力学分析。
