| Registro completo |
| Provedor de dados: |
J. Venom. Anim. Toxins incl. Trop. Dis.
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| País: |
Brazil
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| Título: |
Structural determinants of the hyperalgesic activity of myotoxic Lys49-phospholipase A2
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| Autores: |
Zambelli,Vanessa Olzon
Chioato,Lucimara
Gutierrez,Vanessa Pacciari
Ward,Richard John
Cury,Yara
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| Data: |
2017-01-01
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| Ano: |
2017
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| Palavras-chave: |
Lys49-Phospholipase A2
Hyperalgesia
Site-directed mutagenesis
Myotoxic effect
Edema
Membrane damage
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| Resumo: |
Abstract Background Bothropstoxin-I (BthTx-I) is a Lys49-phospholipase A2 (Lys49-PLA2) from the venom of Bothrops jararacussu, which despite of the lack of catalytic activity induces myotoxicity, inflammation and pain. The C-terminal region of the Lys49-PLA2s is important for these effects; however, the amino acid residues that determine hyperalgesia and edema are unknown. The aim of this study was to characterize the structural determinants for the Lys49-PLA2-induced nociception and inflammation. Methods Scanning alanine mutagenesis in the active-site and C-terminal regions of BthTx-I has been used to study the structural determinants of toxin activities. The R118A mutant was employed as this substitution decreases PLA2 myotoxicity. In addition, K115A and K116A mutants – which contribute to decrease cytotoxicity – and the K122A mutant – which decreases both myotoxicity and cytotoxicity – were also used. The H48Q mutant – which does not interfere with membrane damage or myotoxic activity – was used to evaluate if the PLA2 catalytic site is relevant for the non-catalytic PLA2-induced pain and inflammation. Wistar male rats received intraplantar injections with mutant PLA2. Subsequently, hyperalgesia and edema were evaluated by the paw pressure test and by a plethysmometer. Native and recombinant BthTx-I were used as controls. Results Native and recombinant BthTx-I induced hyperalgesia and edema, which peaked at 2 h. The R118A mutant did not induce nociception or edema. The mutations K115A and K116A abolished hyperalgesia without interfering with edema. Finally, the K122A mutant did not induce hyperalgesia and presented a decreased inflammatory response. Conclusions The results obtained with the BthTx-I mutants suggest, for the first time, that there are distinct residues responsible for the hyperalgesia and edema induced by BthTx-I. In addition, we also showed that cytolytic activity is essential for the hyperalgesic effect but not for edematogenic activity, corroborating previous data showing that edema and hyperalgesia can occur in a non-dependent manner. Understanding the structure-activity relationship in BthTx-I has opened new possibilities to discover the target for PLA2-induced pain.
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| Tipo: |
Info:eu-repo/semantics/article
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| Idioma: |
Inglês
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| Identificador: |
http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1678-91992017000100304
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| Editor: |
Centro de Estudos de Venenos e Animais Peçonhentos
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| Relação: |
10.1186/s40409-017-0099-6
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| Formato: |
text/html
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| Fonte: |
Journal of Venomous Animals and Toxins including Tropical Diseases v.23 2017
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| Direitos: |
info:eu-repo/semantics/openAccess
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