title: Re-evaluation of M-LAO, L-amino acid oxidase, from the venom of Gloydius blomhoffi as an anticoagulant protein.
abstract: Many anticoagulant proteins have been found from snake venoms. Recently, (L)-amino acid oxidase (LAO) from the venom of Gloydius blomhoffi, M-LAO, was reported to inhibit coagulation factor IX; however, the mechanism of its anticoagulant activity is still unclear. Here, we re-evaluated the anticoagulant activity of M-LAO. We first purified M-LAO from the venom of G. blomhoffi, and examined the effect of LAO inhibitors and the hydrogen peroxide scavenger, catalase, on the anticoagulant activity of M-LAO. We found that the isolated M-LAO fraction prolongs the APTT, PT and fibrinogen clotting time and cleaves the Aalpha-chain of fibrinogen. LAO inhibitors or catalase did not inhibit these effects. Detailed analysis revealed that the M-LAO fraction contained a small amount of 39-kDa metalloproteinase. The prolongation of clotting time and degradation of fibrinogen were inhibited by a metalloproteinase inhibitor. Therefore, we concluded that the anticoagulant activity of the M-LAO fraction was caused by the 39-kDa metalloproteinase.
authors.affiliation: Department of Biochemistry, Meiji Pharmaceutical University, Kiyose, Tokyo, Japan.
authors.forename: Daisuke
authors.initials: D
authors.lastname: Fujisawa
authors.forename: Yasuo
authors.initials: Y
authors.lastname: Yamazaki
authors.forename: Takashi
authors.initials: T
authors.lastname: Morita
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D000925:Anticoagulants / Q000737:chemistry / Q000378:metabolism*; D001777:Blood Coagulation / Q000502:physiology*; D002374:Catalase / Q000378:metabolism; D003435:Crotalid Venoms / Q000201:enzymology*; D005164:Factor IX / Q000378:metabolism; D005340:Fibrinogen / Q000378:metabolism; D016166:Free Radical Scavengers; D006801:Humans; D050830:L-Amino Acid Oxidase / Q000037:antagonists & inhibitors / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism*; D045726:Metalloproteases / Q000037:antagonists & inhibitors; D008969:Molecular Sequence Data; D010314:Partial Thromboplastin Time; D011517:Prothrombin Time; D016415:Sequence Alignment; D017819:Viperidae
chemical_list: D000925:Anticoagulants; D003435:Crotalid Venoms; D016166:Free Radical Scavengers; D005164:Factor IX; D005340:Fibrinogen; D002374:Catalase; D050830:L-Amino Acid Oxidase; D045726:Metalloproteases