title: [Purification and properties of human lysozyme in engineered bacterium E. coli].
abstract: To obtain the SDS-PAGE-pure human lysozyme, the crude enzyme of engineered bacterium E. coli was purified by chromatography on cation ion exchange of Express-Ion S. The optimum reaction temperature and pH of this lysozyme were 45 degrees C and 6.5, respectively. The isoelectric point is pH 8.91, and Km of the enzyme for Micrococcus lysodeikticus is 0.0311 mg/mL. The thermal stability of the engineered enzyme is more sensible than hen egg white lysozyme and human milk lysozyme. The sequence of 5 amino acids in N-end is same as designed, except an Met at the first. The affects of some metal ion on this enzyme were shown. Cu2+ of 0.01 mmol/L could completely inactivate the enzyme.
authors.affiliation: Institute of Microbiology, Chinese Academy of Sciences, Beijing 100080.
authors.forename: J
authors.initials: J
authors.lastname: Ye
authors.forename: S
authors.initials: S
authors.lastname: Qian
mesh_terms: D000595:Amino Acid Sequence; D004795:Enzyme Stability; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism*; D006801:Humans; D006863:Hydrogen-Ion Concentration; D009113:Muramidase / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D011994:Recombinant Proteins / Q000302:isolation & purification / Q000378:metabolism; D013696:Temperature
chemical_list: D011994:Recombinant Proteins; D009113:Muramidase