Data/hora: 03/06/2024 18:40:06

Provedor de dados: 	80	
País: 	Brazil	
Título: 	Structural determinants of the hyperalgesic activity of myotoxic Lys49-phospholipase A2	
Autores: 	Zambelli,Vanessa Olzon; Chioato,Lucimara; Gutierrez,Vanessa Pacciari; Ward,Richard John; Cury,Yara.	
Data: 	2017-01-01	
Ano: 	2017	
Palavras-chave: 	Lys49-Phospholipase A2; Hyperalgesia; Site-directed mutagenesis; Myotoxic effect; Edema; Membrane damage.	
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.	
Tipo: 	Info:eu-repo/semantics/article	
Idioma: 	Inglês	
Identificador: 	http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1678-91992017000100304	
Editor: 	Centro de Estudos de Venenos e Animais Peçonhentos	
Relação: 	10.1186/s40409-017-0099-6	
Formato: 	text/html	
Fonte: 	Journal of Venomous Animals and Toxins including Tropical Diseases  v.23 2017	
Fonte: 	info:eu-repo/semantics/openAccess