Department of Chemical Engineering and Applied Chemistry, 200 College Street, University of Toronto, Toronto, ON, M5S3E5, Canada.
Institute of Biomaterials and Biomedical Engineering, 164 College Street, University of Toronto, Toronto, ON, M5S 3G9, Canada.
Bioinformatics. 2019 Dec 15;35(24):5216-5225. doi: 10.1093/bioinformatics/btz445.
In kinetic models of metabolism, the parameter values determine the dynamic behaviour predicted by these models. Estimating parameters from in vivo experimental data require the parameters to be structurally identifiable, and the data to be informative enough to estimate these parameters. Existing methods to determine the structural identifiability of parameters in kinetic models of metabolism can only be applied to models of small metabolic networks due to their computational complexity. Additionally, a priori experimental design, a necessity to obtain informative data for parameter estimation, also does not account for using steady-state data to estimate parameters in kinetic models.
Here, we present a scalable methodology to structurally identify parameters for each flux in a kinetic model of metabolism based on the availability of steady-state data. In doing so, we also address the issue of determining the number and nature of experiments for generating steady-state data to estimate these parameters. By using a small metabolic network as an example, we show that most parameters in fluxes expressed by mechanistic enzyme kinetic rate laws can be identified using steady-state data, and the steady-state data required for their estimation can be obtained from selective experiments involving both substrate and enzyme level perturbations. The methodology can be used in combination with other identifiability and experimental design algorithms that use dynamic data to determine the most informative experiments requiring the least resources to perform.
https://github.com/LMSE/ident.
Supplementary data are available at Bioinformatics online.
在代谢的动力学模型中,参数值决定了这些模型预测的动态行为。从体内实验数据估计参数需要参数具有结构可识别性,并且数据具有足够的信息量来估计这些参数。现有的确定代谢动力学模型中参数结构可识别性的方法由于其计算复杂性,只能应用于小代谢网络的模型。此外,先验实验设计是获得用于参数估计的信息性数据的必要条件,但它也没有考虑到使用稳态数据来估计动力学模型中的参数。
在这里,我们提出了一种基于稳态数据可用性的可扩展方法,用于对代谢动力学模型中的每个通量进行参数结构识别。在这样做的过程中,我们还解决了确定生成稳态数据以估计这些参数的实验数量和性质的问题。通过使用一个小的代谢网络作为示例,我们表明,使用稳态数据可以识别大多数由机械酶动力学速率定律表示的通量中的参数,并且可以从涉及基质和酶水平扰动的选择性实验中获得用于估计它们的稳态数据。该方法可以与其他使用动态数据确定最具信息量的实验的可识别性和实验设计算法结合使用,这些实验需要最少的资源来执行。
https://github.com/LMSE/ident。
补充数据可在 Bioinformatics 在线获得。