Figure 5.
Tuning biosensor response through optimisation of intracellular receptor densities: a) By altering the intracellular concentration of the ligand‐responsive allosteric transcription factor (TF) the output from the response promoter (PR) can be altered. i) For activators, increasing the concentration of transcription factor can increase output from the response promoter making it more sensitive to the target molecule. ii) For repressors reducing the intracellular concentration of the transcription factor can increase the output from the response promoter making it more sensitive to the target molecule.56, 57 b) Altering the intracellular concentration of the target molecule can also be used to alter the response of the biosensor. The intracellular concentration can be increased by engineering import machinery to increase transport into the cell to increase the response.26