title: Purification and characterization of a new serine protease with fibrinolytic activity from the marine invertebrate, Urechis unicinctus.
abstract: A non-hemorrhagic, chymotrypsin-like serine protease, UFEII, was purified from the marine echiuroid worm, Urechis unicinctus, after a combination of chromatography steps. UFEII was monomeric, with an apparent molecular weight of 26.7 kDa via SDS-PAGE. The isoelectric point of UFEII was 4.03, and the maximum activity of the enzyme was observed at 50 °C and pH8.0. According to fibrin plate assays, UFEII could not only directly degrade fibrin and fibrinogen but also activate plasminogen. Further, UFEII preferentially hydrolyzed the fibrinogen γ-chain, followed by the Bβ-chains and Aα-chains. Moreover, ufeII, full length of the gene encoding UFEII, was obtained by RT-PCR, degenerated PCR, and nested PCR. The ufeII was determined to be a 906-bp cDNA containing an open reading frame of 795 bp encoding a putative protein of 264 amino acids with a predicted molecular weight of 27.03 kDa. Besides, UFEII exhibited no hemorrhagic effect. Overall, U. unicinctus may represent a potential source of new therapeutic agents in thrombolytic therapy.
authors.affiliation: College of Marine Life Science, Ocean University of China, Yushan Road #5, Qingdao 266003, China.
authors.forename: Qingqing
authors.initials: Q
authors.lastname: Bi
authors.forename: Jinxin
authors.initials: J
authors.lastname: Chu
authors.forename: Yilin
authors.initials: Y
authors.lastname: Feng
authors.forename: Zhongqing
authors.initials: Z
authors.lastname: Jiang
authors.forename: Baoqin
authors.initials: B
authors.lastname: Han
authors.forename: Wanshun
authors.initials: W
authors.lastname: Liu
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D005343:Fibrinolytic Agents / Q000302:isolation & purification* / Q000494:pharmacology; D015801:Helminth Proteins / Q000302:isolation & purification* / Q000494:pharmacology; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D008670:Metals / Q000494:pharmacology; D051379:Mice; D008969:Molecular Sequence Data; D011077:Polychaeta / Q000201:enzymology; D017386:Sequence Homology, Amino Acid; D057057:Serine Proteases / Q000302:isolation & purification* / Q000494:pharmacology; D013696:Temperature
chemical_list: D005343:Fibrinolytic Agents; D015801:Helminth Proteins; D008670:Metals; D057057:Serine Proteases; C583944:UFEII protein, Urechis unicinctus