This section details all the computational implementations of the "Characterization Approach". We show our method and explain the algorithm allowing, once we have our experimental data, to estimate our parameters. At the end, the final program (coded in Matlab) aiming at a "virtual predictive lab", is described.


Parameters Finder Programs

The data

The experimental data consist typically of two tables, X_data (various concentrations of the transcription factor) and Y_data (corresponding output values).

  • controlling X_data : thanks to the prior characterization of the inductible promoters that control the transcription factor concentrations, we can deduce from the Inv_f1.m and Inv_f2.m functions the necessary concentrations of aTc and arabinose to introduce in the medium to achieve the targeted concentrations of the given transcription factor.
  • Extracting Y_data : the linear conversion between the fluorescence of GFP at maturation and its concentration gives us directly the expected data.

Parameters Finder for our Example

We show hereby the annotated program find_FP.m that is used to estimate, for instance, the parameters in :

  • ƒ5( [FlhDC], 0 ) = β24 * ƒhill( [FlhDC], K2, n2 ) and
  • ƒ5( 0, [FliA] ) = β25 * ƒhill( [FliA], K8, n8 )

All Algorithms

We present here all the algorithms used in our "Characterization Approach".

First, the "prior characterization", e.g. the inducible promoters controlling the master regulators (FlhDC, FliA...) :

Next, the algorithms representing the complete Characterizations, e.g. coupling the above to the downstream promoters activities :

Finally, all the others auxiliary algorithms,as well as the final program code used for our simulations :