Question

2. To study the binding of caffeine to bovine serum albumin by the equilibrium dialysis method, 2.8 x 10-4 M of albumin was allowed to equilibrate with 1 x 10-4 M of caffeine. After the equilibrium was established, 0.7 x 10-4M of caffeine was contained in the dialysis bag and 0.3 x 10-4 M of caffeine was found in the external solution. Calculate r, the ratio of bound to total protein, and B, the fraction of bound caffeine.

Answer 1

Ans: In this experiment Bovine serum albumin is a protein and caffeine is a ligand. Given that (Total) Initial used protein concentration=2.8x10 M (Total) Initial used ligand concentration: 1x104m Bound ligand concentration = 0.7x104m free ligand concentration = 0.3x104m Since bound of protein concentration is directly propotional to the bound ligand concentration so, it can be concluded that r=[bound protein ] [bound ligand ] 0.7x10 m [total protein ] [ total ligand txotm protein - 0.7 x 10 4M 2.8x104m Fraction of bound caffeine (B) = 1-7 where to free ligand concentration total ligand concentration - free ligand concentration = 0.3x104 0.3x104 (1x109 (0.37184) ot x164 i Thus B=1-f or 1 - 2 / 2 wit