The Application Of BLI Technology In Disease Diagnosis And Antibody Purification

Bio-Layer Interferometry (BLI) is a label-free technology for measuring biomolecular interactions. It is an optical analytical technique that analyzes the interference pattern of white light reflected from two surfaces:a layer of immobilized protein on the biosensor tip, and an internal reference layer. Change in the number of molecules bound to the biosensor tip causes a shift in the interference pattern that can be measured in real-time. Due to its high sensitivity, low sample costs and rapid quantitative features, the BLI technology has gained more attention in the applications of biomolecules interactions.This paper included the following projects on disease diagnosis and antibody purification process using BLI technology.(1) With divinyl sulfone (DVS) as a coupling agent, we developed a new antifouling coating for biosensors by tethering natural amino acids on the surface of the sensor. Several amino acids were examined and lysine-coated surface was most effective in reducing nonspecific protein adsorption. Through contact angle and protein adsorption measurements, the optimal conditions for lysine coating was conducted with 50 mM lysine at pH 9.5. Finally, the lysine coating was applied the detection of Tick Borne Encephalitis using BLI sensor. The results were comparable to those obtained from enzyme-linked immunosorbent assay (ELISA). The results indicate the potentical application of the antifouling coating prepared with lysine on the rapid quantitation of serum samples.(2) With DVS as the coupling agent, hydrophobic charge-induction chromatography (HCIC) ligands were covalently immobilized on the BLI sensor surface. Using 4-pyridoethanethiol (MEP) as an example, BLI sensor was employed to monitor the adsorption/dissolciation behaviors of several proteins, e.g.,lgG and serum albumin. The results showed that BLI sensor is feasible to monitor the adsorption/dissociation process of protein on the ligands1 surface. BLI technology provides a conveinet means to evaluate the ligands' performance and optimize the conditions of purification process, showing great potential on antibody purification.In addition, the paper also included some preliminary data of asymmetric transfer hydrogenation with artificial metalloenzyme. We designed and prepared an artificial metalloenzyme based on streptavidin-biotin system. The biotinylated complex was synthesized and the reaction conditions were optimized.1-phenylethanone was used to evaluate the catlalyst and the results showed that the constructed artificial metalloenzyme has good chiral selectivity (ee 42.5%), which means our artificial metalloenzyme is effective in some degree.