Elucidation of direct competition and allosteric modulation of small-molecular-weight protein ligands using surface plasmon resonance methods.

摘要: The present work introduces a surface plasmon resonance-based method for the discrimination of direct competition and allosteric effects that occur in ternary systems comprising receptor protein two small-molecular-weight ligands bind to it. Fatty acid binding 4, fructose-1,6-bisphosphatase human serum albumin were used as model molecules demonstrate performance method. For each molecules, pairs ligand selected which either or an effect had already been determined by other methods. introduced here is based on resonance responses observed at equilibrium when immobilized brought into contact with binary mixtures interacting ligands. These experimentally are compared calculated using theoretical considers both interaction modes. This study demonstrates complex model, enables calculation fractional occupancy such systems, well suited these types responses. all considered this work, experimental chosen concentration ratio range identical within five-σ confidence interval calculations correct mode (direct different regulation), case modulation, also strength effect. model-based predict ideal even single ratios can serve hot spots discrimination, drastically reduce numbers measurements needed between distinct modulation modes (neutral, positive negative allostery).