Conservation laws and unidentifiability of rate expressions in biochemical models

M. Anguelova, G. Cedersund, M. Johansson, C.J. Franzén, B. Wennberg. IET Systems Biology, July 2007, 1(4), 230-237.

Newexperimental techniques in bioscience provide us with high-quality data allowingquantitative mathematical modelling. Parameter estimation is often necessary and, inconnection with this, it is important to know whether allparameters can be uniquely estimated from available data, (i.e. whetherthe model is identifiable). Dealing essentially with models for metabolism,we show how the assumption of an algebraic relation betweenconcentrations may cause parameters to be unidentifiable. If a sufficientdata set is available, the problem with unidentifiability arises locallyin individual rate expressions. A general method for reparameterisation toidentifiable rate expressions is provided, together with a Mathematica codeto help with the calculations. The general results are exemplifiedby four well-cited models for glycolysis.

AUTHORS AND AFFILIATIONS

  • Milena Anguelova, Mathematical Sciences, Chalmers University of Technology
  • Gunnar Cedersund, Fraunhofer-Chalmers Centre
  • Mikael Johansson, Dept of Chemical and Biological Engineering, Chalmers University of Technology
  • Carl Johan Franzén, Dept of Chemical and Biological Engineering, Chalmers University of Technology
  • Bernt Wennberg, Mathematical Sciences, Chalmers University of Technology



Photo credits: Nic McPhee