Study Of The Electric Field On Catalase Conformation And Its Activity

This paper studied the effects of electric field on the secondary structure of CAT(catalase) by circular dichroism technology,Meanwhile the effects of different electric field strength and different treatment time were determined.The relationship between the changes of the secondary structure content and the enzyme activity was tentatively discussed.The research offered the experiment basis of the function and mechanism of electric filed on enzyme protein.Catalse was treated with 50HZ sine-wave electric field,The results showed that:1,after 5 minutes,β-sheet had significantly increased at4.0kv/cm,β-turn had significantly decreased at 2.0kv/cm,random coil had significantly increased at 2.0kv/cm.After 10 minutes,α-helix had significantly increased at 2.0kv/cm.β-sheet had significantly increased at 2.0kv/cm,3.0kv/cm,4.0kv/cm.β-turn had significantly decreased at 2.0kv/cm,3.0kv/cm,4.0kv/cm,random coil had no significantly changes.After 15 minutes,α-helix had significantly decreased at 3.0kv/cm and had significantly increased at 1.0kv/cm,2.0kv/cm,4.0kv/cm,5.0kv/cm.β-sheet had significantly increased at 2.0kv/cm,3.0kv/cm,4.0kv/cm,5.0kv/cm.β-turn had significantly decreased at 2.0kv/cm,4.0kv/cm,5.0kv/cm.radom coil had significantly decreased at 1.0kv/cm,5.kv/cm.The results showed:with the treatment time increased,longer time electric field treatment have more significantly inpact on catalse secondary structure than shorter time treatment.β-sheet andβ-turn tend to transform intoα-helix andβ-sheet, the whole secondary structure of catalase tend to ordering,and with the treatment time increased this tendency became more obvious.2,After 15minutes,activity of catalase had significantly increased at 1.0kv/cm,2.0kv/cm,4.0kv/cm,5.0kv/cm.But activity of catalase had no significantly changes after 5minutes and 10 minutes treatment.3,α-helix andβ-sheet had significantly increased at 1.0kv/cm,2.0kv/cm, 4.0kv/cm,5.0kv/cm after 15 minutes treatment,and the activity had significantly increased at above Processing conditions.α-helix had significantly decreased at 3.0kv/cm after 15minutes,butβ-sheet had significantly increased at same processing condition.The overall content ofα-helix andβ-sheet had increased but had no significantly changes,activity of catalase also had increased but had no significantly.This showed that the activity had the relationship with the overall content ofα-helix andβ-sheet.4,The electric field had no effect on third structure of catalase,but secondary structure and activity had changes.This is because electric field may not affect space conformation(third structure) of the active center,but may affect Partial conformation(secondary structure),then leaded to the changes of activity.