Myotoxic phospholipases A2 in Bothrops snake venoms: Effect of chemical modifications on the enzymatic and pharmacological properties of bothropstoxins from Bothrops jararacussu

 

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Autores: Andrião Escarso, Silvia H., Soares, Andreimar Martins, Rodrigues, Veridiana M., Angulo Ugalde, Yamileth, Díaz Oreiro, Cecilia, Lomonte, Bruno, Gutiérrez, José María, Giglio, José Roberto
Formato: artículo original
Fecha de Publicación:2000
Descripción:Venoms from eight Bothrops spp. were fractionated by ion-exchange chromatography on CM-Sepharose at pH 8.0 for the purification of myotoxins. Chromatographic profiles showed differences regarding myotoxic components among these venoms. B. alternatus, B. atrox and B. jararaca venoms did not show the major basic myotoxic fractions identified in the other venoms. Polyacrylamide gel electrophoresis for basic proteins also showed distinct patterns for these toxins. In vivo, all the isolated myotoxins induced release of creatine kinase due to necrosis of muscle fibers, accompanied by polymorphonuclear cell infiltration, and edema in the mouse paw. In addition, the toxins showed cytotoxic and liposome-disrupting activities in vitro. B. jararacussu bothropstoxins-I (BthTX-I) and II (BthTX-II) were submitted to chemical modifications of: His, by 4-bromophenacyl bromide (BPB) or photooxidation by Rose Bengal (RB); Tyr, by 2-nitrobenzenesulphonyl fluoride (NBSF); and Trp, by o-nitrophenylsulphenyl chloride (NPSC). The myotoxic and cytotoxic activities of BthTX-I, a Lys49 PLA2 homologue, after modification by BPB, RB, NBSF and NPSC, were reduced to 50%, 20%, 75%, 65% and 13%, 0.5%, 76%, 58%, respectively. However, the edema-inducing and liposome-disrupting activities were not significantly reduced by the above modifications. BPB-treated BthTX-II, an Asp49 PLA2 homologue, lost most of its catalytic, indirect hemolytic, anticoagulant, myotoxic and cytotoxic activities. The edema-inducing and liposome-disrupting activities were reduced to 50% and 80%, respectively. Lethality caused by BthTX-I and -II was strongly reduced after treatment with BPB or RB, but only partially with NBSF or NPSC. BthTX-I and -II, both native or modified, migrated similarly in a charge-shift electrophoresis. Antibodies raised against BthTX-I or -II, B. asper Basp-II and the C-terminal 115-129 peptide from Basp-II did not show significant differences in their cross-reactivity with the modified toxins, except with RB photooxidized toxins.
País:Kérwá
Institución:Universidad de Costa Rica
Repositorio:Kérwá
OAI Identifier:oai:kerwa.ucr.ac.cr:10669/29470
Acceso en línea:http://www.sciencedirect.com/science/article/pii/S0300908400011500
https://hdl.handle.net/10669/29470
Palabra clave:Bothrops venoms
Myotoxins
Phospholipases A2
Pharmacological Activity
Chemical Modifications