Study On The Effects Of Low Energy N～+ Ions Implantation And Vacuum On The Enzyme Conformation And Its Activity

After several decades' development, ion beam radiation technique has beensuccessfully applied on several fields, such as plant improvement, cell etching andgene transfer. At present, the study on the mechanism of biological effect mostlyfocuses on cell. The research on damage to DNA strand breaks, nucleotide and basehas made great progress in the molecule level. But it has not been reported for theeffect of low energy N~+ ions implantation on molecular structure and the activity ofenzyme protein.This paper studies the effects of low energy N~+ ions implantation and vacuumtreatment on the secondary structure of HRP(Horseradish peroxidase) andSOD(Superoxide dismutase) by CD (Circular dichroism) technology, Meanwhile theeffects of different dose of low energy N~+ ions implantation and vacuum treatment onenzymatic activity are determined, and the relationship between the changes of thesecondary structure content and the enzyme activity is tentatively discussed.This research show that the HRP and SOD are treated with different dose low energy ions and vacuum, both the content of protein secondary structure and theactivity of HRP and SOD changed in various degrees. The changed patterns ofsecondary structure and activity of HRP and SOD are non-monotonic and also thetrend and the degree are different. The activity change of each enzyme is related tothe content of their secondary structure. The activity of HRP and SOD bombardedwith low energy ions and treated by vacuum is increased which is respectively relatedto the increased content ofβ-shee and of a-helix in their structure.It is supposed that the process of low energy ions implantation organism changesthe secondary structure of enzyme protein and the change of secondary structureleads to changed activity and produce different biological effects on microscopy. Thisresearch offers the experiment and theory basis for giving the exposition of therelationship between the structure and the function of enzyme protein and of themechanism of low energy ion implantation on biological material.