title: Effect of site-specific PEGylation on the fibrinolytic activity, immunogenicity, and pharmacokinetics of staphylokinase.
abstract: The bacterial plasminogen-activator staphylokinase (Sak) is a promising thrombolytic agent for treating acute myocardial infarction. To effectively reduce the immunogenicity of Sak while maintaining its fibrinolytic activity, site-specific PEGylation was performed in the present study. The chemoselective cysteine PEGylation site was selected within an immunodominant region (amino acid residues 71-87) using an in silico approach. The PEGylated Sak variants prepared in this study showed a purity of >97.0%. PEGylation at Position 80 resulted in a Sak variant Sak(E80C-PEG) which has similar fibrinolytic activity and thermostability compared with the native recombinant staphylokinase (r-Sak). The immunogenicity of Sak(E80C-PEG) in guinea pigs was greatly reduced compared with the native r-Sak. Furthermore, preliminary pharmacokinetic results suggested that the plasma clearance of Sak(E80C-PEG) from the blood stream of rabbit was significantly decreased compared with that of r-Sak, resulting in a 2.8-fold increase of initial half-life and a 3.8-fold increase of systemic availability. In summary, these results demonstrated that site-specific PEGylation yielded a novel Sak variant Sak(E80C-PEG) with remarkable advantages over the unmodified Sak.
authors.affiliation: College of Life Science, Hebei Normal University, Shijiazhuang 050024, China.
authors.forename: Jianwei
authors.initials: J
authors.lastname: Liu
authors.affiliation: College of Life Science, Hebei Normal University, Shijiazhuang 050024, China.
authors.forename: Zhu
authors.initials: Z
authors.lastname: Wang
authors.affiliation: College of Life Science, Hebei Normal University, Shijiazhuang 050024, China hejintian@yahoo.com zhaobaohua86178@sohu.com.
authors.forename: Jintian
authors.initials: J
authors.lastname: He
authors.affiliation: College of Environmental Science and Engineering, Hebei University of Science and Technology, Shijiazhuang 050018, China.
authors.forename: Gaizhen
authors.initials: G
authors.lastname: Wang
authors.affiliation: College of Life Science, Hebei Normal University, Shijiazhuang 050024, China.
authors.forename: Rongbo
authors.initials: R
authors.lastname: Zhang
authors.affiliation: College of Life Science, Hebei Normal University, Shijiazhuang 050024, China hejintian@yahoo.com zhaobaohua86178@sohu.com.
authors.forename: Baohua
authors.initials: B
authors.lastname: Zhao
mesh_terms: D000818:Animals; D001483:Base Sequence; D017931:DNA Primers; D004591:Electrophoresis, Polyacrylamide Gel; D004795:Enzyme Stability; D004797:Enzyme-Linked Immunosorbent Assay; D005342:Fibrinolysis; D007700:Kinetics; D008666:Metalloendopeptidases / Q000276:immunology / Q000378:metabolism / Q000493:pharmacokinetics*; D010958:Plasminogen / Q000378:metabolism; D011092:Polyethylene Glycols / Q000737:chemistry*; D011817:Rabbits
chemical_list: D017931:DNA Primers; D011092:Polyethylene Glycols; D010958:Plasminogen; D008666:Metalloendopeptidases; C022653:auR protein, Staphylococcus aureus
keywords: fibrinolytic activity; immunogenicity; pharmacokinetic; site-specific pEGylation; staphylokinase