Conformational entropy and internal dynamics upon protein ligand binding.

Conformational changes and protein dynamics are closely linked to protein ligand interactions. Both the conformational entropy and internal dynamics can change upon ligand binding. The proposed system of biotin and streptavidin has a stoichiometry of 4 biotin per streptavidin. Previous experiments have shown that while the internal dynamics differ for different timescales the change in conformational entropy is the same. The thermal stability of streptavidin has been shown to be affected by the ratio of biotin to streptavidin.[1] This suggests that even below saturation level a change in the whole protein is initialised, indicating a cooperative binding process. A Fourier transformation of the data allows for the extension of the dynamic range and thus overlaps with the timescale analysed in the also proposed OSIRIS experiment.1. M.Gonzales et al. 1999, Biomolecular Engineering, 16 67-72