Study On Immobilization Of Superoxide Dismutase And Catalase By Polyaspartic Acid Grafted With Cetyl Chain

Superoxide dismutase(SOD)can alternately catalyze the superoxide free radical(02)which causes the disproportionation reaction to become common molecular oxygen(O2)and hydrogen peroxide(H2O2).Superoxide dismutase has a key antioxidant effect in human production and life.Catalase(CAT)catalyzes the conversion of hydrogen peroxide(H2O2)to water(H2O)and oxygen(O2).So that the superoxide dismutase catalyzed by the reaction of hydrogen peroxide into a completely harmless substances,and can promote the superoxide dismutase catalytic reaction.Immobilized enzyme to improve the stability of the enzyme,and easy to recycling,re-use,for the environment also has a protective effect,has a strong practical significance,so immobilized enzyme has a strong practical significance.In this paper,SOD-ELP and CAT-ELP were purified and purified under the appropriate conditions.Then,the soluble polymer carrier grafted cetyl group was prepared by hydrolysis of acid catalyzed thermal polycondensation,water bath and alkaline condition.Chain of polyaspartic acid(PASP-C16).The SOD-ELP and CAT-ELP were then immobilized onto PASP-C16 using NHS-EDC chemical cross-linking.It was concluded that the cross-linked single enzyme and the cross-linked double enzyme were active and the activity loss was not significant compared with the free enzyme.In addition,by comparing the activity of the cross-linked single enzyme and the cross-linked double enzyme,it was concluded that CAT could promote SOD catalytic reaction,the two enzymes have synergistic effect.It is proved that the cross-linked double enzyme can more effectively improve the reaction rate and have a broader market prospect.In addition,the carrier,free enzyme and immobilized enzyme were characterized by scanning electron microscopy,infrared spectroscopy,fluorescence spectroscopy,laser scanning confocal microscopy and circular dichroism spectroscopy.Scanning electron microscopy,infrared spectroscopy and laser scanning confocal microscopy showed that the single enzyme SOD and the double enzyme SOD-CAT were immobilized on the vector PASP-C16 by cross-linking.Fluorescence Spectra The quenching reaction of the enzyme before and after immobilization using the fluorescence quencher acrylamide resulted in an increase in the stability of the enzyme,which prevented the enzyme from changing the structure of the protein due to environmental changes.The circular dichroism spectrum(CD)analyzes the secondary structure of the enzyme before and after immobilization.The conclusion is that immobilization does not cause the secondary structure of the enzyme to change too much,and the content of a-helix is slightly Some decline,irregular curl more,can be initially to ensure that the enzyme activity is not lost.