Shown below is a binding curve for a drug binding to a single binding site on a target protein.

From this curve estimate the fraction of protein molecules that will be bound to the drug when the concentration of the drug added to the solution is 20 nM.

Your answer should be given as a number, e.g., 0.5, not 50% (do not type any additional characters)

A heterodimeric protein is composed of two subunits that have similar structures. Each subunit is able to bind to the same ligand molecule. Binding of the ligand to one subunit induces a conformational change in the protein such that the affinity of the ligand for the second subunit increases.

Which of the following binding curves is/are likely to represent this type of protein-ligand interaction?

A protein binds to a small molecule ligand with an equilibrium dissociation constant (K_d) of 20 nM.

In a sample containing the protein (10 pM) and the small molecule ligand (2 μM), what proportion of the protein molecules will be bound to the small molecule ligand at equilibrium?

In the course of their investigations into cancer cell growth, a team of pharmaceutical researchers has discovered a critical oncoprotein (a protein that promotes cancer cell growth).

Now they have developed a new drug that binds to a single site on the oncoprotein with an equilibrium dissociation constant (K_d) of 200 pM.

What concentration of the drug would they need to mix with the oncoprotein so that 90% of the oncoprotein molecules will be bound to the drug?

Shown below is a binding curve for a ligand binding to a single binding site on a protein.

From this curve estimate the equilibrium dissociation constant (K_d) for this protein-ligand interaction.

Three different mutant forms of myoglobin bind to oxygen with different affinities.

Their rank order of oxygen affinity is (from strongest to weakest):

Mutant Z > Mutant X > Mutant Y

The oxygen binding curves for these mutants are shown below.

Which curve corresponds to which mutant?

In the course of their investigations into cancer cell growth, a team of pharmaceutical researchers has discovered a critical oncoprotein (a protein that promotes cancer cell growth).

Now they have developed a new drug that binds to a single site on the oncoprotein with an equilibrium dissociation constant (K_d) of 200 pM.

What concentration of the drug would they need to mix with the oncoprotein so that 99% of the oncoprotein molecules will be bound to the drug?

A single polypeptide chain folds to form a two-domain protein. The two domains have similar primary and tertiary structures enabling them to bind to the same ligand molecule. Binding of the ligand to one domain has no influence on the affinity of the ligand for the other domain.

Which of the following binding curves is/are likely to represent this type of protein-ligand interaction?

A protein binds to a small molecule ligand with an equilibrium dissociation constant (K_d) of 300 nM.

In a sample containing the protein (10 pM) and the small molecule ligand (3 nM), what proportion of the protein molecules will be bound to the small molecule ligand at equilibrium?

Three different mutant forms of myoglobin bind to oxygen with different affinities.

Their rank order of oxygen affinity is (from strongest to weakest):

Mutant Z > Mutant X > Mutant Y

The oxygen binding curves for these mutants are shown below.

Which curve corresponds to which mutant?