Application Of Concanavalin A For Prepare Biocatalyst

Biocatalysis has excellent stereoselectivity and high catalytic efficiency,which is of great significance to the production of chiral compounds.Therefore,the development of new and efficient biocatalysts has attracted the attention of researchers.Enzyme immobilization can effectively improve the operational stabilities of biological enzyme which is an important biocatalyst,so that it can resist or not be affected by the extreme environment in practical production applications and exert better catalytic efficiency.With the efforts of many researchers,the techniques and materials used in enzyme immobilization research have been continuously developing and innovating.In recent years,biological macromolecules with specific recognition effects have been applied to the study of immobilization,and by conjunction with appropriate carrier materials,the directional immobilization of biological enzymes can be achieved.Therefore,this article studies and explores several methods for preparing biocatalysts using ConA as a functional component.The main research contents and conclusions are as follows:(A)A magnetically immobilization carrier capable of orientationally immobilizing glycosyl-modified enzymes was prepared by combining ConA with magnetic nanoparticles.The carrier adsorbed and immobilized chloroperoxidase,glucose oxidase and laccase in aqueous solution,and reached immobilization yield of higher than 90%and activity recovery of more than 80%,indicating that the ConA functionalized carrier can be extended to a variety of glycosyl-modified enzymes.(B)Using the prepared functionalized carrier,the immobilized CPO and the co-immobilized of CPO and GOx were prepared.The immobilized CPO retains similar activity and stability to that of free enzyme,can repeatedly catalyze the asymmetric synthesis of modafinil with 70%e.e..The co-immobilized GOx-CPO has higher catalytic efficiency than the free enzyme,and its reusability has been improved more than two times after cross-linking,and it also can effectively catalyze the synthesis of modafinil at pH6.(C)Study the preparation of active ConA-Vanadium(IV)complexes and explore the relevant coordination mechanisms.The activity of complexes is mainly affected by concentration of metal ion,pH conditions of coordination and catalysis.Carrying out the coordination in pH 9 conditions and catalysis in pH2 conditions,the highest catalytic rate would been achieved and the binding effect is strong enough to resist the destruction of centrifugation.The E.coli cell which expressing recombinant ConA can indeed promote the catalysis of synthesis of modafinil by VO2+ and reaching a substrate conversion rate of approximately 100%after reaction for 16h.