title: Purification and characterization of a novel fibrinolytic enzyme from the polychaete, Neanthes japonica (Iznka).
abstract: A novel fibrinolytic enzyme from Neanthes japonica (Iznka), named NJF, was purified to electrophoretic homogeneity using ammonium sulfate precipitation, hydrophobic interaction, ion exchange and gel-filtration chromatography. NJF consisted of a single polypeptide chain with a molecular weight of 28-32 kDa, which was determined by MALDI-TOF mass spectrum and SDS-PAGE. The isoelectric point of NJF determined by isoelectric focusing electrophoresis (IEF) was 4.4, and the maximum activity of the enzyme was observed at 60 degrees C and pH 9.0. The cleavage speed of fibrinogen by NJF affected the Aalpha-chain first, followed by the Bbeta-chain and finally the gamma-chain. NJF activity was strongly inhibited by PMSF, indicating that it is a serine protease. Partial amino-acid sequences of its fragments were different from those of other known fibrinolytic enzymes. N. japonica may thus represent a potential source of new therapeutic agents to treat thrombosis.
authors.affiliation: Department of Biochemistry and Molecular Biology, Norman Bethune College of Medicine, Jilin University, Changchun, Jilin 130021, China.
authors.forename: Zhihui
authors.initials: Z
authors.lastname: Deng
authors.forename: Shaohua
authors.initials: S
authors.lastname: Wang
authors.forename: Qi
authors.initials: Q
authors.lastname: Li
authors.forename: Xue
authors.initials: X
authors.lastname: Ji
authors.forename: Lianzhi
authors.initials: L
authors.lastname: Zhang
authors.forename: Min
authors.initials: M
authors.lastname: Hong
mesh_terms: D000645:Ammonium Sulfate / Q000737:chemistry; D000818:Animals; D000845:Annelida / Q000378:metabolism*; D001709:Biotechnology / Q000379:methods; D002850:Chromatography, Gel; D002852:Chromatography, Ion Exchange / Q000379:methods; D004591:Electrophoresis, Polyacrylamide Gel; D005340:Fibrinogen / Q000737:chemistry; D006863:Hydrogen-Ion Concentration; D007526:Isoelectric Point; D010447:Peptide Hydrolases / Q000737:chemistry; D011077:Polychaeta / Q000378:metabolism*; D057057:Serine Proteases / Q000737:chemistry; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D013696:Temperature; D013927:Thrombosis / Q000628:therapy
chemical_list: D005340:Fibrinogen; D010447:Peptide Hydrolases; D057057:Serine Proteases; D000645:Ammonium Sulfate