Copy of The effect of different ligands on the change in conformational entropy in BCA

Changes of protein conformational entropy ΔS_conf and hydration layers are relevant for ligand-binding. The protein-ligand binding is governed by equilibrium thermodynamics ΔG=ΔH-TΔS, it occurs if ΔG is minimised. Previous work showed entropy-entropy compensation occurs between the protein streptavidin and its hydration layer. Another interesting system is bovine carbonic anhydrase II (BCAII). This protein has many compatible ligands. Two of these are 4-fluorobenzenesulfonamide (4-FBS) and pentafluorobenzenesulfonamide (PFBS). Analysing BCAII with 4-FBS and PFBS creates the opportunity to analyse different ligand binding affinities and their ΔS_conf. For this we aim to perform quasielastic neutron scattering experiments on BCAII in the ligand free and bound state for each ligand at different temperatures. We expect to see a negative ΔS_conf, as the ligand reduces the proteins flexibility