5′-Nucleotidase from Vipera lebetina venom. (January 2015)

• Record Type: Journal Article
• Authors: Trummal, Katrin; Samel, Mari; Aaspõllu, Anu; Tõnismägi, Külli; Titma, Tiina; Subbi, Juhan; Siigur, Jüri; Siigur, Ene
• Is Part Of: Toxicon. Volume 93(2015)
• Page Start: 155
• Page End: 163
• Publication Date: 2015-01
• Subjects: Vipera lebetina -- Snake venom -- 5′-nucleotidase -- cDNA cloning -- MALDI-TOF MS -- Platelet aggregation; Toxins -- Periodicals; Venom -- Periodicals; 615.9
• DOI: 10.1016/j.toxicon.2014.11.234
• Languages: English
• ISSNs: 0041-0101

Abstract

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. Highlights: Vipera lebetina venom comprises 5′-NTs having different molecular forms and isoforms. One isoform of 120 kDa homodimeric 5′-NT (VL5′NT) has been purified to homogeneity. The VL5′NT inhibits ADP- or collagen-induced platelet aggregation. The translated sequence confirms the belonging of VL5′NT into ecto-5′-nucleotidases.