# IGEM:IMPERIAL/2006/project/Oscillator/project browser/Test Sensing Prey Construct/Modelling

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Jump to navigationJump to searchSuper Parts | Prey Construct | ||
---|---|---|---|

Actual Part | T9002: Test Sensing Prey Construct | ||

Sub Parts | F2620 | intermediate_part | intermediate_part |

## Model assumptions and relevance

- General assumptions on gene expression modelling:
- Quasi-steady state hypothesis on mRNA expression.
- Gene activation can be approximated by Hill equations.

- Assumptions linked to the quorum sensing:
- As a first approximation, we assume that luxR and AHL molecules form a heterodimer (even if it has been found that the complex formed is more complicated)
- The relationship between the heterodimer formed from LuxR and AHL in activating genes is linear
- LuxR is at steady state since it is under the control of the constitutive promoter tetR
- LuxR is in excess of AHL (ie not saturated by AHL)

## Model description

- Mathematical Description of GFP levels (prey sensitivity):

- [math] \frac{d[GFP]}{dt} = \frac{a \times [AHL]}{a_{0} + [AHL]} - d_{GFP} \times [GFP][/math]

- For a full derivation, see Modelling Prey Sensing Test Construct

## Model variables and parameters

Variables
| ||||

Name | Description | Initial Value | Confidence | Reference |
---|---|---|---|---|

AHL | Acyl Homoserince Lactone representing the prey molecule | Concentration Range varying between 0nM and 10uM | known | links |

GFP | Green Fluorescent Protein to act as PoPs | 0 | to be measured | links |

Parameters
| ||||

Name | Description | Value | Confidence | Reference |
---|---|---|---|---|

a | population-dependent | ? | to be extracted using experimental data | links |

a_{0} |
constant | ? | to be extracted using experimental data | links |

d_{GFP} |
degradation constant due to GFP degradation (Half-life 45min.) | ? | to be extracted using experimental data | links |

## Dynamical and sensitivity analysis

N/A

## Characterization

- Describe how you plan to use the modelling to characterize the part