Identification of the Specific Binding Proteins of Bioactive Small Compound Using Affinity Resins

For preparation of “chemical shotgun (CSG)” affinity resins, bioactive compounds are nonselectively immobilized via one of their functional groups by a simple protocol without the design and synthesis of specific derivatives. The CSG affinity resins have merit of capture of specific-binding proteins through multisurfaces of the compound, compared to the conventional affinity resins in which compound is immobilized only through a designated surface. We have shown that this nonselective immobilization is effective for both natural compounds bearing multifunctional groups such as FK506 and compounds bearing no inherent functional group such as Valdecoxib. We also show versatile and alternative method to widely-used competition method for identification of specific binding protein among binding proteins on affinity resins, because application of the traditional one is often restricted by poor solubility of compounds.