(Solved): Problem 1 (15 points). Binding of low-affinity ligand (A) to cell-surface receptors can be determi ...

Problem 1 (15 points). Binding of low-affinity ligand (A) to cell-surface receptors can be determined in competition assay with a radioactively-labeled high-affinity ligand (B) bound to the receptors. The two ligands bindings can be described by \( A+R=A R \) and \( B+R=B R \), respectively. Based on our lecture in class, derive an equation to calculate the binding affinity \( \left(\mathrm{K}_{\mathrm{A}}\right) \) for ligand \( \mathrm{A} \) if the binding affinity \( \left(\mathrm{K}_{\mathrm{B}}\right) \) is known. Detailed derivation steps are required to get a full credit.