title: UFEIII, a fibrinolytic protease from the marine invertebrate, Urechis unicinctus.
abstract: A new serine protease with fibrinolytic activity from a marine invertebrate, Urechis unicinctus, was purified to electrophoretic homogeneity using column chromatography. SDS-PAGE of the purified enzyme showed a single polypeptide chain with MW ~20.8 kDa. Its N-terminal sequence was IIGGSQAAITSY. The purified enzyme, UFEIII, was stable at pH 6-10 below 60 °C with an optimum pH of 8.5 at approx. 55 °C. The enzyme activity was significantly inhibited by PMSF and SBTI suggesting that it was a serine protease. In fibrin plate assays, UFEIII was contained 1.46 × 10(3 )U (urokinase units) mg(-1) total fibrinolytic activity, which consisted of 692 U mg(-1) direct fibrinolytic activity and 769 U mg(-1) plasminogen-activator activity. Km and Vmax values for azocasein were 1 mg ml(-1) and 43 μg min(-1) ml(-1), respectively.
authors.affiliation: College of Marine Life Science, Ocean University of China, Qingdao, China. qingdaoqqb@gmail.com
authors.forename: Qingqing
authors.initials: Q
authors.lastname: Bi
authors.forename: Baoqin
authors.initials: B
authors.lastname: Han
authors.forename: Wanshun
authors.initials: W
authors.lastname: Liu
authors.forename: Yilin
authors.initials: Y
authors.lastname: Feng
authors.forename: Zhongqing
authors.initials: Z
authors.lastname: Jiang
mesh_terms: D000818:Animals; D002853:Chromatography, Liquid; D004591:Electrophoresis, Polyacrylamide Gel; D004795:Enzyme Stability; D005343:Fibrinolytic Agents / Q000737:chemistry / Q000302:isolation & purification*; D015801:Helminth Proteins / Q000737:chemistry / Q000302:isolation & purification*; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D008970:Molecular Weight; D011077:Polychaeta / Q000201:enzymology*; D057057:Serine Proteases / Q000737:chemistry / Q000302:isolation & purification*; D013696:Temperature
chemical_list: D005343:Fibrinolytic Agents; D015801:Helminth Proteins; D057057:Serine Proteases