Team:RDFZ-China/Model
Modelling
Bound Fraction &Unbound Fraction
By defining a simple equation where P is the promoter region and X is the ligand that can bind with P, namely a repressor in this case:
Intuitively, the factional saturation of the promoter is denoted by Ps , which is the fraction of occupied binding sites:
At equilibrium of this reaction, the rate of forward reaction and that of backward reaction are the same:
Then we rearrange this equation and get:
Where kd is the dissociation constant of this binding event. Now we substitute equation 1.3 into equation 1.1 and hence obtain:
Assuming that the sum of the bound and the unbound equals one, the unbound fraction Pu is thus:
Bound fraction is considered for activation in gene regulation and unbound fraction for repressive regulation.
Modelling Equations
Methods
Results
Discussion
