Please use this identifier to cite or link to this item: http://repositorio.unicamp.br/jspui/handle/REPOSIP/200525
Type: Artigo de periódico
Title: Chemical Modifications Of Phtx-i Myotoxin From Porthidium Hyoprora Snake Venom: Effects On Structural, Enzymatic, And Pharmacological Properties.
Author: Huancahuire-Vega, Salomón
Corrêa, Daniel H A
Hollanda, Luciana M
Lancellotti, Marcelo
Ramos, Carlos H I
Ponce-Soto, Luis Alberto
Marangoni, Sergio
Abstract: We recently described the isolation of a basic PLA2 (PhTX-I) from Porthidium hyoprora snake venom. This toxin exhibits high catalytic activity, induces in vivo myotoxicity, moderates footpad edema, and causes in vitro neuromuscular blockade. Here, we describe the chemical modifications of specific amino acid residues (His, Tyr, Lys, and Trp), performed in PhTX-I, to study their effects on the structural, enzymatic, and pharmacological properties of this myotoxin. After chemical treatment, a single His, 4 Tyr, 7 Lys, and one Trp residues were modified. The secondary structure of the protein remained unchanged as measured by circular dichroism; however other results indicated the critical role played by Lys and Tyr residues in myotoxic, neurotoxic activities and mainly in the cytotoxicity displayed by PhTX-I. His residue and therefore catalytic activity of PhTX-I are relevant for edematogenic, neurotoxic, and myotoxic effects, but not for its cytotoxic activity. This dissociation observed between enzymatic activity and some pharmacological effects suggests that other molecular regions distinct from the catalytic site may also play a role in the toxic activities exerted by this myotoxin. Our observations supported the hypothesis that both the catalytic sites as the hypothetical pharmacological sites are relevant to the pharmacological profile of PhTX-I.
Subject: Amino Acids
Animals
Catalytic Domain
Cell Line
Group Ii Phospholipases A2
Mice
Neurotoxins
Protein Structure, Secondary
Reptilian Proteins
Snake Venoms
Rights: aberto
Identifier DOI: 10.1155/2013/103494
Address: http://www.ncbi.nlm.nih.gov/pubmed/23484072
Date Issue: 2013
Appears in Collections:Artigos e Materiais de Revistas Científicas - Unicamp

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