Which mаcrоmоlecules cаn be brоken down into intermediаte products that enter cellular respiration?
RPE65 is а mаjоr prоtein оf unknown function found аssociated with the human eye that is associated with a number of different eye diseases. One hypothesis is that RPE65 is an enzyme involved in the chemical synthesis of the pigment that makes the human eye light sensitive. In a search as to which pathway intermediate RPE65 acts on, the following dissociation constants were measured (Table 1). They were compared to BSA, which stands for bovine serum albumin and is found in large concentrations in cow milk. Table 1: Binding Constants of Various Retinoids with RPE65 and BSA in pM (10^-12 M). The numbers in brackets ( ) indicate the errors of the binding constant determination. Ligands RPE65 (pM) BSA (pM) A: all-trans-retinyl palmitate 20 (6) 2143 (790) B: 11-cis-retinyl palmitate 14224 (3006) 2310 (611) C: all-trans-retinol 1078 (144) 2316 (1216) D: 11-cis-retinol 3811 (100) 2143 (800) Part A. 4 points What is the purpose of comparing the dissociation constants of 4 different ligands with two different proteins, RPE65 and BSA? Part B. 5 points What is the association constant for 11-cis-retinol binding to RPE65? Part C. 5 points What is the difference in standard binding free energy between ligand A binding to RPE65 as compared to BSA. Part D. 4 points Which is the best (highest affinity) ligand for RPE65? Justify your choice. Part E. 4 points Would you say that RPE65 binding to any of the ligands is specific? Justify your answer. Part F. 10 points If you add a 10 nanomolar concentration of ligand A to a solution containing RPE65, what percent of ligand A is bound to RPE65? Part G. 10 points If you repeat the same experiment as in part F with BSA, i.e. if you add a 10 nanomolar concentration of ligand A to a solution containing BSA, what percent of ligand A is bound to BSA? Solve this problem on paper, document your approach and provide intermediate results. Report the final answers with 3 significant figures. Scan the pages(s) and upload them for grading. Answer all parts A to G.