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Robust adaptation and homeostasis by autocatalysis.
T Drengstig1, X Y Ni, K Thorsen
1Department of Electrical Engineering and Computer Science, University of Stavanger, N-4036 Stavanger, Norway.
The Journal of Physical Chemistry. B
|April 18, 2012
Summary
Autocatalysis, a chemical reaction where a product speeds up its own formation, can achieve robust homeostasis. This study demonstrates autocatalysis as an alternative mechanism for integral control, ensuring stable system regulation.
Area of Science:
- Systems Biology
- Biochemical Regulation
- Control Theory
Background:
- Homeostasis is crucial for organism survival and adaptation in dynamic environments.
- Integral feedback is a control engineering principle enabling robust, perturbation-independent adaptation.
- Previous work linked integral control to zero-order fluxes in negative feedback loops involving a controlled variable (A) and controller molecule (E).
Purpose of the Study:
- To investigate autocatalysis as an alternative mechanism for achieving integral control.
- To explore the regulatory roles of autocatalysis in biological systems.
- To analyze the homeostatic properties of systems exhibiting autocatalysis.
Main Methods:
- Modeling of two-component negative feedback loops.
- Analysis of the Lotka-Volterra oscillator (LVO) with autocatalysis in both variable A and controller E.
- Mathematical analysis of system stability and average concentrations.
Main Results:
- Autocatalysis was shown to be an alternative mechanism for achieving integral control.
- Despite concerns about stability in Lotka-Volterra oscillators with autocatalysis, homeostasis in average concentrations ( and
) was observed. - Autocatalysis demonstrated regulatory roles beyond simply driving reactions.
Conclusions:
- Autocatalysis can serve as a regulatory mechanism to achieve robust homeostasis.
- The presence of autocatalysis in biological systems can lead to stable average concentrations of key molecules.
- Autocatalysis offers a novel perspective on achieving integral control in biological feedback systems.
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