title: 5'-Nucleotidase from Vipera lebetina venom.
abstract: 5'-Nucleotidase (5'-NT) is widely represented in animal tissues (CD73) as well as in almost all snake venoms. In the present study, a 5'-NT isoform has been isolated from Vipera lebetina venom. The homodimeric isoform consists of monomers with molecular masses of 60 kDa. The enzyme is thermolabile and has pH optimum at 7.5. The 5'-NT activity is inhibited by metal ions Fe(3+), Cu(2+) and Zn(2+), enhanced by Mn(2+) while Mg(2+) and Ca(2+) have no remarkable effect. In addition to 120-kDa protein there are higher molecular forms of 5'-NT present in the V. lebetina venom. The cloning and sequencing of the 5'-NT coding cDNA resulted in 5'-truncated construct. MALDI-TOF and Orbitrap mass-spectrometry of the tryptic peptides confirmed the translated N-terminally truncated protein sequence concordance to the 5'-NT isolated from the venom. The isolated protein strongly inhibited ADP- or collagen-induced platelet aggregation.
authors.affiliation: National Institute of Chemical Physics and Biophysics, Tallinn, Estonia.
authors.forename: Katrin
authors.initials: K
authors.lastname: Trummal
authors.affiliation: National Institute of Chemical Physics and Biophysics, Tallinn, Estonia.
authors.forename: Mari
authors.initials: M
authors.lastname: Samel
authors.affiliation: National Institute of Chemical Physics and Biophysics, Tallinn, Estonia.
authors.forename: Anu
authors.initials: A
authors.lastname: Aaspõllu
authors.affiliation: National Institute of Chemical Physics and Biophysics, Tallinn, Estonia.
authors.forename: Külli
authors.initials: K
authors.lastname: Tõnismägi
authors.affiliation: National Institute of Chemical Physics and Biophysics, Tallinn, Estonia; Tallinn University, Tallinn, Estonia.
authors.forename: Tiina
authors.initials: T
authors.lastname: Titma
authors.affiliation: National Institute of Chemical Physics and Biophysics, Tallinn, Estonia.
authors.forename: Juhan
authors.initials: J
authors.lastname: Subbi
authors.affiliation: National Institute of Chemical Physics and Biophysics, Tallinn, Estonia.
authors.forename: Jüri
authors.initials: J
authors.lastname: Siigur
authors.affiliation: National Institute of Chemical Physics and Biophysics, Tallinn, Estonia. Electronic address: ene.siigur@kbfi.ee.
authors.forename: Ene
authors.initials: E
authors.lastname: Siigur
mesh_terms: D015720:5'-Nucleotidase / Q000235:genetics* / Q000302:isolation & purification; D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D002850:Chromatography, Gel; D002852:Chromatography, Ion Exchange; D017931:DNA Primers / Q000235:genetics; D004591:Electrophoresis, Polyacrylamide Gel; D008958:Models, Molecular; D008969:Molecular Sequence Data; D010974:Platelet Aggregation / Q000187:drug effects; D011487:Protein Conformation; D017422:Sequence Analysis, DNA; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D014757:Viper Venoms / Q000201:enzymology* / Q000633:toxicity; D017819:Viperidae / Q000235:genetics* / Q000378:metabolism
chemical_list: D017931:DNA Primers; D014757:Viper Venoms; D015720:5'-Nucleotidase
keywords: 5′-nucleotidase; MALDI-TOF MS; Platelet aggregation; Snake venom; Vipera lebetina; cDNA cloning