title: Sulfonation of papain-treated chitosan and its mechanism for anticoagulant activity.
abstract: The novel low-molecular-weight chitosan polysulfate (MW 5120-26,200 Da) was prepared using the depolymerization of chitosan with papain (EC. 3.4.22.2). The sulfonation of depolymerized products was performed using chlorosulfonic acid in N,N-dimethylformamide under semi-heterogeneous conditions. The structures of the products were characterized by FTIR, (13)C NMR, and (1)H NMR (1D, 2D NMR) spectroscopy. The present study sheds light on the mechanism of anticoagulant activity of chitosan polysulfate. Anticoagulant activity was investigated by an activated partial thromboplastin assay, a thrombin time assay, a prothrombin time assay, and thrombelastography. Surface plasmon resonance also provided valuable data for understanding the relationship between the molecular binding of sulfated chitosan to two important blood clotting regulators, antithrombin III and heparin cofactor II. These results show that the principal mechanism by which this chitosan polysulfate exhibits anticoagulant activity is mediated through heparin cofactor II and is dependent on polysaccharide molecular weight.
authors.affiliation: Thailand Excellence Center for Tissue Engineering, Department of Biochemistry, Faculty of Medicine, Chiang Mai University, Chiang Mai 50200, Thailand.
authors.forename: Jiraporn
authors.initials: J
authors.lastname: Suwan
authors.forename: Zhenqing
authors.initials: Z
authors.lastname: Zhang
authors.forename: Boyangzi
authors.initials: B
authors.lastname: Li
authors.forename: Preeyanat
authors.initials: P
authors.lastname: Vongchan
authors.forename: Puttinan
authors.initials: P
authors.lastname: Meepowpan
authors.forename: Fuming
authors.initials: F
authors.lastname: Zhang
authors.forename: Shaker A
authors.initials: SA
authors.lastname: Mousa
authors.forename: Shaymaa
authors.initials: S
authors.lastname: Mousa
authors.forename: Bhusana
authors.initials: B
authors.lastname: Premanode
authors.forename: Prachya
authors.initials: P
authors.lastname: Kongtawelert
authors.forename: Robert J
authors.initials: RJ
authors.lastname: Linhardt
mesh_terms: D000925:Anticoagulants / Q000737:chemistry* / Q000378:metabolism / Q000494:pharmacology*; D000990:Antithrombin III / Q000378:metabolism; D048271:Chitosan / Q000737:chemistry* / Q000378:metabolism / Q000494:pharmacology*; D015844:Heparin Cofactor II / Q000378:metabolism; D006801:Humans; D009682:Magnetic Resonance Spectroscopy; D008970:Molecular Weight; D010206:Papain / Q000378:metabolism*; D013451:Sulfonic Acids / Q000737:chemistry*
chemical_list: D000925:Anticoagulants; D013451:Sulfonic Acids; D015844:Heparin Cofactor II; D000990:Antithrombin III; D048271:Chitosan; D010206:Papain