Question4

=Text of the Question:= toc Strickland et al. (2008) have engineered a photoswitchable trpytophan repressor protein. Draw the free energy diagram for binding of the protein in the dark, following by illumination. What is the change in the free energy of binding upon illumination?


 * Potential Clue:** Figure 1A of the referenced paper shows a mini-energy diagram which I think is showing the different energy states of a given conformation, with the right conformation being more energetically favorable. When the protein is illuminated, the energy curve in Figure 1A shifts to raise the Gibbs Free Energy of the right conformation and now making the left conformation more energetically favorable.

=Free Energy Diagrams:=

=Change in the Free Energy of binding upon Illumination:=

=Relevant Literature:=

4.1. Strickland, D., K. Moffat, et al. (2008). "Light-activated DNA binding in a designed allosteric protein." Proceedings of the National Academy of Sciences 105(31): 10709-10714. DOI:10.1073/pnas.0709610105