title: Low molecular weight factor X activator from Cerastes vipera (Sahara sand viper) venom.
abstract: Fraction G from Cerastes vipera venom previously purified on Sephadex G100 was refractionated on DEAE-Sephadex A50 column. A factor X activator was obtained. It had a mol. wt of 12,500 and an isoelectric point of 4.4. It shortened the plasma recalcification time of normal plasma, and plasmas deficient in factors V, VII, VIII, IX, XI and XIII, while it had no effect on plasma deficient in factor X or factor II. It had a serine protease activity and a minimal plasmin activity. PMSF, leupeptin and iodoacetamide exerted a pronounced inhibitory effect on its serine protease activity. Polyantivenin could neutralize the coagulant activity of the activator.
authors.affiliation: Department of Biochemistry, Faculty of Medicine, Ain Shams University, Cairo, Egypt.
authors.forename: T
authors.initials: T
authors.lastname: Farid
authors.forename: H
authors.initials: H
authors.lastname: Nasser
authors.forename: K
authors.initials: K
authors.lastname: Zaki
authors.forename: M F
authors.initials: MF
authors.lastname: el-Asmar
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001777:Blood Coagulation / Q000187:drug effects*; D003546:Cysteine Endopeptidases / Q000737:chemistry / Q000235:genetics / Q000302:isolation & purification / Q000494:pharmacology*; D004789:Enzyme Activation; D005170:Factor X / Q000187:drug effects / Q000378:metabolism*; D008969:Molecular Sequence Data; D008970:Molecular Weight; D009363:Neoplasm Proteins; D012697:Serine Endopeptidases / Q000378:metabolism*; D014757:Viper Venoms / Q000737:chemistry*; D017819:Viperidae
chemical_list: D009363:Neoplasm Proteins; D014757:Viper Venoms; D005170:Factor X; D012697:Serine Endopeptidases; D003546:Cysteine Endopeptidases; C030910:cancer procoagulant