title: Sequence determination and anticoagulant and antithrombotic activities of a novel sulfated fucan isolated from the sea cucumber Isostichopus badionotus.
abstract: BACKGROUND
  The aim is to analyze the structure, anticoagulant and antithrombotic activities of a sulfated fucan isolated from sea cucumber Isostichopus badionotus (fucan-Ib).
  
  
  METHODS
  Fucan-Ib was hydrolyzed under mild acid conditions. The oligosaccharide fragments were fractionated by gel-filtration chromatography and the structures were determined by negative-ion electrospray tandem mass spectrometry with collision-induced dissociation and two-dimensional NMR. Anticoagulant activities were measured by activated partial thromboplastin, thrombin and prothrombin times, and by in vitro inhibition experiments with factors IIa and Xa. Antithrombotic activities were determined in vitro by measuring the length and weight of the thrombus generated.
  
  
  RESULTS
  The linear polysaccharide sequence of fucan-Ib was deduced from the structures of its oligosaccharide fragments produced by acid hydrolysis. Under mild conditions, the glycosidic bonds between the non-sulfated and 2,4-O-disulfated fucose residues were selectively cleaved and highly ordered oligosaccharide fragments with a tetrasaccharide repeating unit [→3Fuc(2S,4S)α1→3Fuc(2S)α1→3Fuc(2S)α1→3Fucα1→]n were obtained. In in vitro assays fucan-Ib showed good anticoagulant and antithrombotic activities compared with heparin and the fucosylated chondroitin sulfate isolated from the same source (fCS-Ib). The two polysaccharides, fucan-Ib and fCS-Ib, differ in the mechanism of action; the former exhibited activity mainly by potentiation of antithrombin acted on thrombin and factor Xa whereas the latter mainly through heparin cofactor II.
  
  
  CONCLUSIONS
  Fucan-Ib has a well defined structure with tetrasaccharide tandem repeats and good anticoagulant and antithrombotic activities. GENERAL IMPORTANCE: Fucan-Ib has a well defined structure and can be readily quality-controlled, and therefore has potential therapeutic value as an affective antithrombotic drug with low risk of bleeding.
authors.affiliation: College of Biosystem Engineering and Food Science, Zhejiang University, Hangzhou 310029, China.
authors.forename: Shiguo
authors.initials: S
authors.lastname: Chen
authors.forename: Yaqin
authors.initials: Y
authors.lastname: Hu
authors.forename: Xinqian
authors.initials: X
authors.lastname: Ye
authors.forename: Guoyun
authors.initials: G
authors.lastname: Li
authors.forename: Guangli
authors.initials: G
authors.lastname: Yu
authors.forename: Changhu
authors.initials: C
authors.lastname: Xue
authors.forename: Wengang
authors.initials: W
authors.lastname: Chai
mesh_terms: D000818:Animals; D000925:Anticoagulants / Q000302:isolation & purification / Q000494:pharmacology*; D001777:Blood Coagulation / Q000187:drug effects*; D001780:Blood Coagulation Tests; D002240:Carbohydrate Sequence; D015951:Factor Xa / Q000378:metabolism; D065427:Factor Xa Inhibitors; D009682:Magnetic Resonance Spectroscopy; D008297:Male; D008969:Molecular Sequence Data; D011134:Polysaccharides / Q000737:chemistry* / Q000302:isolation & purification / Q000494:pharmacology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D012616:Sea Cucumbers / Q000737:chemistry*; D017421:Sequence Analysis; D021241:Spectrometry, Mass, Electrospray Ionization; D053719:Tandem Mass Spectrometry; D013917:Thrombin / Q000378:metabolism; D013927:Thrombosis / Q000188:drug therapy*
chemical_list: D000925:Anticoagulants; D065427:Factor Xa Inhibitors; D011134:Polysaccharides; C007789:fucoidan; D013917:Thrombin; D015951:Factor Xa