title: Chemical modification of L-asparaginase from Escherichia coli with a modified polyethyleneglycol under substrate protection conditions.
abstract: L-Asparaginase was chemically modified with 2,4-bis(O-methoxypolyethyleneglycol)-6-chloro-S-triazine (mPEG2) in the presence of L-asparagine. Optimal modification was performed under the condition that the molar ratio of mPEG2/-NH2 is 10. The modified enzyme retained 33% of initial enzymatic activity with complete abolishment of immunogenicity. In vitro half-life increment from 4.6 h to 33 h has been obtained.
authors.affiliation: State Key Laboratory of Bioreactor Engineering, Research Institute of Biochemistry, East China University of Science and Technology, Shanghai 200237, PR China.
authors.forename: Jian-Feng
authors.initials: JF
authors.lastname: Zhang
authors.forename: Ling-Yang
authors.initials: LY
authors.lastname: Shi
authors.forename: Dong-Zhi
authors.initials: DZ
authors.lastname: Wei
mesh_terms: D001215:Asparaginase / Q000737:chemistry*; D001709:Biotechnology / Q000379:methods*; D002845:Chromatography; D002846:Chromatography, Affinity; D004305:Dose-Response Relationship, Drug; D004591:Electrophoresis, Polyacrylamide Gel; D004926:Escherichia coli / Q000201:enzymology*; D011092:Polyethylene Glycols / Q000737:chemistry*; D013997:Time Factors
chemical_list: D011092:Polyethylene Glycols; D001215:Asparaginase