Based on the dissociation constant Kd, the protein - ligand pair that has the strongest interaction is (A) insulin and insulin receptor (Kd = 1 × 10−10). (B) avidin and biotin (Kd... Based on the dissociation constant Kd, the protein - ligand pair that has the strongest interaction is (A) insulin and insulin receptor (Kd = 1 × 10−10). (B) avidin and biotin (Kd = 1 × 10−15). (C) HIV surface protein and anti-HIV IgG (Kd = 4 × 10−10). (D) calmodulin and calcium (Kd = 3 × 10−6).
Understand the Problem
The question is asking to identify which protein-ligand pair has the strongest interaction based on their dissociation constants (Kd). A lower Kd value indicates a stronger interaction, hence we need to compare the given Kd values of each pair.
Answer
Avidin and biotin (Kd = 1 × 10⁻¹⁵) have the strongest interaction.
The protein-ligand pair with the strongest interaction is avidin and biotin with a dissociation constant (Kd) of 1 × 10⁻¹⁵.
Answer for screen readers
The protein-ligand pair with the strongest interaction is avidin and biotin with a dissociation constant (Kd) of 1 × 10⁻¹⁵.
More Information
A lower dissociation constant (Kd) indicates a stronger binding affinity between a protein and a ligand. The avidin-biotin interaction is one of the strongest known non-covalent interactions in biological systems.
Tips
A common mistake is to assume that a higher Kd value indicates a stronger interaction. In fact, the opposite is true: a lower Kd signifies stronger binding affinity.
Sources
- Avidin-Biotin Interaction | Thermo Fisher Scientific - US - thermofisher.com
- The Principles and Applications of Avidin-Based Nanoparticles in ... - pmc.ncbi.nlm.nih.gov
