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Binding Affinity

Searches for protein-ligand complexes in the PDB with associated binding affinity from BindingDB ( and BindingMOAD ( The minimum or maximum value for the binding affinity range may be left unspecified in which case only the provided end of the range is used. The binding affinity type can be specified from the drop down list, and the default type is "Ki". Binding constants IC50, EC50, Ki, and Kd are in nM, thermodynamic data ΔG, ΔH, -TΔS in kJ/mol, and Ka in M-1.


Enter "Between 1 and 5" and select "Affinity Type EC50". The search results will be PDB entries of protein-ligand complexes with an EC50 in the 1 - 5 nm (inclusive) range. For example the Thyroid Hormone Receptor has an EC50 of 2 nM for 3,5,3'TRIIODOTHYRONINE (T3), PDB ID 3GWS.

Leave lower bound and upper bound unspecified, and the results will be all PDB entries that have binding data for the selected binding affinity type.