Question

A $25,000$ Da protein contains a single binding site for a molecule(ligand), whose molecular weight is $2,500$Da. Assuming high affinity and physiologically irreversible binding, the amount of the liquid required to occupy all the binding sites in $10$mg protein will be

• A. $0.1$mg
• B. $1$mg
• C. $10$mg
• D. $100$mg

Answer 1

Answer: (B)

$1$mg

It is given that 25,000 Da protein contains single binding site for ligand with molecular weight 2,500 Da.

Hence, 10 mg of protein will require approximately 10 x 2,500 / 25, 000 = 1 mg of ligand to occupy all the binding sites in protein.

Thus, the correct answer is option B.