Hi everyone,
Does exist any threshold for binding affinity value between macromolecules?
E.g. Any value lower than -5.0 Kcal/Mol.....
How to determine that the binding affinity among different molecules are significantly different?
E.g. molecule A - ligand 1 = -4.7 Kcal/Mol molecule A - ligand 2 = -5.0 kcal/mol
How to determine to which ligand (1 or 2) my molecule A have significantly more affinity?
Thank you
If you have the binding energies for protein-ligand complexes, you can determine their binding affinities by:
ΔG°= -RTlnKd
Lesser the binding energy (the more negative of the free binding energy results in the formation of stronger complexes) better is the binding of the ligand and protein.
you may get ki according to Arrhenius equation of (Tushar answer) be in nanomolar
There is no fixed threshold - Whether you get significant binding depends on the concentration of the binding partners: Kd=[L]*[R]/[LR]. For proteins that are present at high concentration, a relatively high Kd (low affinity) may be sufficient to get significant binding (micromolar or worse). However , if the concentrations of the proteins are low, higher affinity is required. For antibody-antigen interactions or Cell surface Receptor - Hormone interactions, Kd s in the low nanomolar or sub-nanomolar range are considered high affinity interactions.
- Badges
- Science topic
- Similar topics
- Computer Science and Engineering
- Bioinformatics