| Texto completo | |
| Autor(es): |
Vanessa Olzon Zambelli
[1]
;
Lucimara Chioato
[2]
;
Vanessa Pacciari Gutierrez
[3]
;
Richard John Ward
[4]
;
Yara Cury
[5]
Número total de Autores: 5
|
| Afiliação do(s) autor(es): | [1] Butantan Institute. Special Laboratory for Pain and Signaling - Brasil
[2] University of São Paulo. School of Philosophy, Sciences and Letters of Ribeirão Preto. Department of Chemistry - Brasil
[3] Butantan Institute. Special Laboratory for Pain and Signaling - Brasil
[4] University of São Paulo. School of Philosophy, Sciences and Letters of Ribeirão Preto. Department of Chemistry - Brasil
[5] Butantan Institute. Special Laboratory for Pain and Signaling - Brasil
Número total de Afiliações: 5
|
| Tipo de documento: | Artigo Científico |
| Fonte: | Journal of Venomous Animals and Toxins including Tropical Diseases; v. 23, 2017-03-16. |
| 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. (AU) | |
| Processo FAPESP: | 02/12906-0 - Efeito nociceptivo por fosfolipase a2 variante lys49: avaliacao do mecanismo de acao atraves do uso de mutacoes pontuais de bothropstoxina-i. |
| Beneficiário: | Vanessa Olzon Zambelli |
| Modalidade de apoio: | Bolsas no Brasil - Iniciação Científica |