Open‐Tubular Affinity Capillary Electrochromatography Based on Immobilized Receptor by Pore Entrapment With Metal–Organic Frameworks

This paper introduces a novel preparation of open-tubular affinity capillary electrochromatography (OT-ACEC) columns through immobilizing proteins by pore entrapment with metal-organic frameworks (MOFs) to rapidly investigate drug-protein interactions. The MOFs material PCN-333(Al) was used to immobilize the model receptor bovine hemoglobin (BHb) for preparing BHb@MOFs, and the affinity chromatography BHb@MOFs/PDA@capillary was created through the immobilization of BHb@MOFs facilitated by polydopamine (PDA). The disappearance of the mesoporous pore of PCN-333 (Al) proved the encapsulation of BHb within the pore of PCN-333(Al). The BHb@MOFs/PDA@capillary column exhibited a good affinity screening and separation ability to distinguish flavonoids and sulfonamides. Besides, the normalized capacity factor (K_IRCE) was used to evaluate drug-protein interactions and related to apparent migration times and the amount of immobilized protein. The binding constant (K_a) values was derived from fluorescence quenching analysis, and a robust positive correlation was observed between K_IRCE and lg K_a (R = 0.94783, p < 0.00001). These results indicate that K_IRCE can be used as an effective index to evaluate the affinity between protein molecules and drug molecules and the OT-ACEC has the potential to predict drug activity.