Study On Surface Modification And Performance Of Glucose Oxidase By RAFT Polymerization

Protein-polymer conjugates can exhibit higher biological activities compared to unmodified proteins. As a result, synthesis and characterization of these materials is of interest to researchers in the fields of medicine, biotechnology, nanotechnology, mechanical engineering, polymer chemistry, and bioengineering. However, the decrease activity of protein-polymer conjugates is a problem. In this paper, we report two methods to solve the problems.First, we synthesized the raft agent with a disulfide bond and 2-mercaptothiazoline ester functional end group, followed by using the raft agent to synthesize biocompatible polymer and thermosensitive copolymer. Then, we covalently linked the two kinds of polymer to glucose oxidase surface through amidation reaction in mild reaction conditions respectively, producing two glucose oxidase-polymer conjugates. The results show that when using the reducing agent disulfide threitol(DTT) to break off the polymer chains from the surface of glucose oxidase, we found that the enzymatic activity was partly restored. The glucose oxidase modified with thermosensitive copolymer exhibited different performance. when the system temperature below the lowest critical solution temperature(LCST) of the copolymers, the enzymatic activity was lower than it of the system temperature above the LCST. In addition, the conjugates enzymatic activity was almost no loss with temperature cycling.In this study, we used 1H NMR spectra, ultraviolet spectrophometer, polyacrylamide gel electrophoresis to characterized and analyzed the two kinds of glucose oxidasepolymer conjugates. The results show that the two methods proposed in this paper can solve the problem, which the enzymatic activity decrease caused by the polymer. In addition, these smart enzyme-polymer conjugates are expected to have great potential in the fields of biotechnology and biomedicine.