Determination of protein-ligand binding affinity by NMR: observations from serum albumin model systems.
The usefulness of bovine serum albumin (BSA) as a model protein for testing NMR methods for the study of protein-ligand interactions is discussed. Isothermal titration calorimetry established the binding affinity and stoichiometry of the specific binding site for L-tryptophan, D-tryptophan, naproxen, ibuprofen, salicylic acid and warfarin. The binding affinities of the same ligands determined by NMR methods are universally weaker (larger KD). This is because the NMR methods are susceptible to interference from additional non-specific binding. The L-tryptophan-BSA and naproxen-BSA systems were the best behaved model systems.
Fielding
Lee
L
AKZO-Nobel Pharma Division, Organon Laboratories Ltd, Newhouse, Lanarkshire ML1 5SH, UK. l.fielding@organon.co.uk
Rutherford
Samantha
S
Fletcher
Dan
D
D000818:Animals; D002151:Calorimetry; D002417:Cattle; D007052:Ibuprofen / Q000737:chemistry; D008024:Ligands; D009682:Magnetic Resonance Spectroscopy / Q000379:methods*; D008956:Models, Chemical; D015394:Molecular Structure; D009288:Naproxen / Q000737:chemistry; D011485:Protein Binding; D011506:Proteins / Q000737:chemistry*; D012459:Salicylates / Q000737:chemistry; D012709:Serum Albumin / Q000737:chemistry*; D014364:Tryptophan / Q000737:chemistry; D014859:Warfarin / Q000737:chemistry
D008024:Ligands; D011506:Proteins; D012459:Salicylates; D012709:Serum Albumin; D009288:Naproxen; D014859:Warfarin; D014364:Tryptophan; D007052:Ibuprofen