A Restriction Enzyme from Escherichia coli Purification and General Properties


An endonuclease restriction enzyme has been purified from E. coli about 40-fold withDNAse and RNAse recoveries of about 3%. The purification steps included precipitationof the enzyme with ammonium sulphate, and reclaimed it through Sephadex G-100 andDEAE-cellulose chromatography. The purified endonuclease was able to break lambdaDNA into three bands. The enzyme has 5% of carbohydrate moiety which means it is aglycoprotein. Lastly, the comparison with other commercial restriction endonucleasesproves that this enzyme is a restriction enzyme with enzymic activity dependent onMg2+