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Team:Imperial College London/Drylab/Protein Production
From 2009.igem.org
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===Conclusion=== | ===Conclusion=== | ||
*The greater the strength of the Lac promoter, the greater the repressive action of LacI prior IPTG induction. | *The greater the strength of the Lac promoter, the greater the repressive action of LacI prior IPTG induction. | ||
| - | *The greater the Lac promoter leakiness (k<sub>leak<sub>) the greater the basal amount of expression of protein of interest, prior IPTG induction. | + | *The greater the Lac promoter leakiness (k<sub>leak</sub>) the greater the basal amount of expression of protein of interest, prior IPTG induction. |
*The greater the amount of IPTG introduced, the greater the size of the bump in production of protein of interest. | *The greater the amount of IPTG introduced, the greater the size of the bump in production of protein of interest. | ||
*Here we assumed that the range of IPTG we have introduced is non-toxic for our cells. Growth curves will tell us whether IPTG does limit cell growth at the ranges we are interested in. | *Here we assumed that the range of IPTG we have introduced is non-toxic for our cells. Growth curves will tell us whether IPTG does limit cell growth at the ranges we are interested in. | ||
Revision as of 18:31, 6 October 2009
- Overview
- The model
- Simulations
Protein Production
Based on the Genetic circuit, a LacI-IPTG inducible promoter is responsible for kickstarting the production of the drug.
- In the absence of IPTG, LacI represses the production of the drug (Cellulase or PAH)
- When IPTG is introduced, the LacI repressing pathway is “de-repressed”, and some output protein is produced.
Contents |
Our goals
The modelling aims to provide an overview and better understanding of the M1 system’s function by:
- Characterizing the system.
- Modeling to account for several factors that may reduce/hinder the production of the protein drug such as:
- Lac promoter leakiness
- IPTG toxicity
- Stability of output protein
This module is an integral part of the design, as large-scale commercialization of the drug of interest depends on finding the optimal conditions for protein production.
about the model assumptions and predictions!
The System
There are 6 differential equations that describe the behaviour of this system.
about the equations and what they mean!
Summary of simulation results
- When we introduce IPTG into the system, it temporarily removes LacI from the system. Hence, during this period of time, we produce the drug of interest.
- When the effects of IPTG wear off, the system returns to equilibrium.
- The more IPTG we add in, the higher the amount of output protein.
about the simulations!
- The effects of IPTG toxicity were investigated and we found that for these concentration ranges, IPTG is not toxic to cells. See the pdf of results for further details:Media:II09_IPTG_growth.ogg
- The constants in this model are arbitrary. We justify our usage of these values with a more detailed dynamical analysis of the system, which shows that it can only have fixed points[ref Strogatz]. Media:II09_Prot_stability analysis.ogg
Conclusion
- The greater the strength of the Lac promoter, the greater the repressive action of LacI prior IPTG induction.
- The greater the Lac promoter leakiness (kleak) the greater the basal amount of expression of protein of interest, prior IPTG induction.
- The greater the amount of IPTG introduced, the greater the size of the bump in production of protein of interest.
- Here we assumed that the range of IPTG we have introduced is non-toxic for our cells. Growth curves will tell us whether IPTG does limit cell growth at the ranges we are interested in.
