Study On Immobilization Of Dehaloperoxidase By Metal Coordination

Dehaloperoxidase(DP)can oxidatively dehalogenate halogenated phenols in sewage into non-toxic corresponding benzoquinones,which is helpful for the environment.Because DP needs H2O2 as a co-substrate to catalyze and oxidize the substrate,when there is too much H2O2,it will cause the enzyme to denature and inactivate.Therefore,this topic uses the method of biomimetic mineralization to immobilize DP to improve its stability and catalytic activity.Since the active center of DP is heme,which mainly exists in the ferrous state,an appropriate amount of Fe2+ is introduced into the mineralization system to increase the enzyme activity.First,Zn,2-methylimidazole(HmIm),FeSO4 and DP are used to form DP@Zn&Fe&HmIm coordination polymer.It is found through experiments that when 0.03mM Fe2+ is added,the immobilized enzyme can catalyze 68.32%of the substrate 2,4,6-trichlorophenol(TCP)conversion,which is 1.52 times higher than the catalytic efficiency of free DP.Subsequently,an enzyme-inorganic hybrid nanoflower biomimetic mineralization method was used to immobilize DP.In this immobilization system,zinc and copper were used as inorganic metals,and an appropriate amount of Fe2+ was added to the immobilization system.The formed immobilized enzyme DP@Zn&Fe&PO4 can catalyze 80.04%of TCP oxidation,which is 1.78 times higher than the catalytic efficiency of free DP,and DP@Cu&Fe&PO4 can catalyze 86.84%of TCP oxidation,which is 1.93 times higher than the catalytic efficiency of free DP.The DP immobilized by the two methods has good temperature stability and pH stability.