title: CoaTx-II, a new dimeric Lys49 phospholipase A2 from Crotalus oreganus abyssus snake venom with bactericidal potential: Insights into its structure and biological roles.
abstract: Snake venoms are rich and intriguing sources of biologically-active molecules that act on target cells, modulating a diversity of physiological functions and presenting promising pharmacological applications. Lys49 phospholipase A2 is one of the multifunctional proteins present in these complex secretions and, although catalytically inactive, has a variety of biological activities, including cytotoxic, antibacterial, inflammatory, antifungal activities. Herein, a Lys49 phospholipase A2, denominated CoaTx-II from Crotalus oreganus abyssus, was purified and structurally and pharmacologically characterized. CoaTx-II was isolated with a high degree of purity by a combination of two chromatographic steps; molecular exclusion and reversed-phase high performance liquid chromatography. This toxin is dimeric with a mass of 13868.2 Da (monomeric form), as determined by mass spectrometry. CoaTx-II is rich in Arg and Lys residues and displays high identity with other Lys49 PLA2 homologues, which have high isoelectric points. The structural model of dimeric CoaTx-II shows that the toxin is non-covalently stabilized. Despite its enzymatic inactivity, in vivo CoaTx-II caused local muscular damage, characterized by increased plasma creatine kinase and confirmed by histological alterations, in addition to an inflammatory activity, as demonstrated by mice paw edema induction and pro-inflammatory cytokine IL-6 elevation. CoaTx-II also presents antibacterial activity against gram negative (Pseudomonas aeruginosa 31NM, Escherichia coli ATCC 25922) and positive (Staphyloccocus aureus BEC9393 and Rib1) bacteria. Therefore, data show that this newly purified toxin plays a central role in mediating the degenerative events associated with envenomation, in addition to demonstrating antibacterial properties, with potential for use in the development of strategies for antivenom therapy and combating antibiotic-resistant bacteria.
authors.affiliation: IKIAM - Universidad Regional Amazónica, Km 7 Via Muyuna, Tena, Napo, Ecuador; Department of Biochemistry and Tissue Biology, Institute of Biology, Campinas State University (UNICAMP), Campinas, SP, Brazil; International Network of Ecuadorian Snakes Venoms Studies (RIEVSE), Ecuador. Electronic address: rafaeldealmeida@ikiam.edu.ec.
authors.forename: J R
authors.initials: JR
authors.lastname: Almeida
authors.affiliation: Department of Biochemistry and Tissue Biology, Institute of Biology, Campinas State University (UNICAMP), Campinas, SP, Brazil.
authors.forename: M
authors.initials: M
authors.lastname: Lancellotti
authors.affiliation: Oswaldo Cruz Fundation (FIOCRUZ), CEBio, Fiocruz Rondônia and Federal University of Rondônia, Porto Velho, RO, Brazil; International Network of Ecuadorian Snakes Venoms Studies (RIEVSE), Ecuador.
authors.forename: A M
authors.initials: AM
authors.lastname: Soares
authors.affiliation: Oswaldo Cruz Fundation (FIOCRUZ), CEBio, Fiocruz Rondônia and Federal University of Rondônia, Porto Velho, RO, Brazil; International Network of Ecuadorian Snakes Venoms Studies (RIEVSE), Ecuador.
authors.forename: L A
authors.initials: LA
authors.lastname: Calderon
authors.affiliation: Centro de Bioinformàtica y Simulación Molecular (CBSM), Universidad de Talca, 2 Norte 685, Casilla 721, Talca, Chile.
authors.forename: D
authors.initials: D
authors.lastname: Ramírez
authors.affiliation: Centro de Bioinformàtica y Simulación Molecular (CBSM), Universidad de Talca, 2 Norte 685, Casilla 721, Talca, Chile; International Network of Ecuadorian Snakes Venoms Studies (RIEVSE), Ecuador.
authors.forename: W
authors.initials: W
authors.lastname: González
authors.affiliation: Department of Biochemistry and Tissue Biology, Institute of Biology, Campinas State University (UNICAMP), Campinas, SP, Brazil.
authors.forename: S
authors.initials: S
authors.lastname: Marangoni
authors.affiliation: IKIAM - Universidad Regional Amazónica, Km 7 Via Muyuna, Tena, Napo, Ecuador; International Network of Ecuadorian Snakes Venoms Studies (RIEVSE), Ecuador.
authors.forename: S L
authors.initials: SL
authors.lastname: Da Silva
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D000890:Anti-Infective Agents / Q000494:pharmacology*; D002850:Chromatography, Gel; D056148:Chromatography, Reverse-Phase; D003435:Crotalid Venoms / Q000737:chemistry* / Q000201:enzymology; D019281:Dimerization; D008239:Lysine / Q000737:chemistry*; D008297:Male; D008826:Microbial Sensitivity Tests; D054467:Phospholipases A2 / Q000737:chemistry / Q000494:pharmacology*; D011487:Protein Conformation; D017386:Sequence Homology, Amino Acid; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization
chemical_list: D000890:Anti-Infective Agents; C000618999:CoaTx-II, Crotalus oreganus abyssus; D003435:Crotalid Venoms; D054467:Phospholipases A2; D008239:Lysine
keywords: Antibacterial effect; Crotalus oreganus abyssus; Lys49 phospholipase A(2); Myotoxicity; Snake venom