4) *** You are studying the binding of a ligand (L) to two different proteins (PA and PB). You devise a method for measuring the concentration of the bound complexes ([PAL] and [PBL}) as a function of ligand concentration ([L]). Wanting to analyze the affinities and cooperativities of these interactions, you conduct measurements of [PAL] and [PBL] as a function of [L]. The data are shown in the tables below. Protein Pa Protein PB [L], UM [PAL]UM [L), UM [PL] UM 0 0.000 0 0.00 5 0.040 15 0.21 10 0.067 30 0.33 50 100 0.55 0.143 0.182 200 300 0.68 500 0.192 1000 0.74 2000 0.198 3000 0.76 4000 0.199 6000 0.77 a) After you have completed the experiments, you realize that you have not measured the free protein ([PA] and [PB]) or the total protein concentrations. You are really worried because you think you have no way of measuring O now. But your advisor tells you that actually you don't need this information in this case! Why? b) Determine the Kd values for each protein. Which one binds the ligand tighter? c) Is the binding for the two proteins cooperative or non-cooperative? Discuss your reasoning