Isolation, Purification, Characterization And Modification Of Groups Of Lysozyme From Duck Egg White

Lysozyme (Lysozyme EC3.2.1.17) called Mucopetide,is a kind of Glycosidase enzymes. It can hydrolyze the glucoside bond β-1,4between N-acetylglucosamine the N-acetylmuramic acid,demage peptide chitsan stents, and crack cells under the action of internal osmatic pressure.Lysozyme is considered to be a self-defense s enzyme,which is widely existed in serum,mucus and many organs of vertebrates.Lysozyme have destroy the fuction of bacterial cell walls, which is widely used in Food,Medicine, Gene and Cell engineering.The main results were as follows:Lysozyme was from Duck Egg White by ammonium sulfate precipitation,CM-sepharose chromatography and gel filtration chromatography on Superdex-200. The specific activity was33687.26U/mg, The yield of lysozyme was27.80%,and the purification fold was109.44.The relative molecular weight of the lysozyme from Duck Egg White was about14.82kD, The optimal pH and temperature against Micrococcus lysodlekticus were pH7.0and50℃,respectively,and the enzyme was stable at temperature below50℃and pH5.0-9.0. The apparent Km values was0.0864mg/mL. Zn2+, Cu2+,Co2+can activate the enzyme activity, ascorbic acid,KSCN, Mg2+, Mh2+inhibited the activity, SDS, Fe2+inhibitd the enzyme activity strongly, methano1ethanol and isopropanol inhibited the activity, methanol had slightly effect on the enzyme activity, ethanol was nest, isopropanol was strongest inhibitors. The chemical modification of the functional groups of the enzyme using different reagents, the results show that Chloramine-T and BrAc PCMB have a strong inhibitory effect to the lysozyme from Duck Egg White,PMSF can activate the activaty, While PCMB, Maleic anhydride,DTT,BD have little effect on activity of the enzyme.