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Lable at the end of the articlepharmacological activities characterized by myotoxic
Lable at the end of the articlepharmacological activities characterized by myotoxic, neurotoxic, anticoagulant, hypotensive, hemolytic, platelet aggregation inhibition, bactericidal, pro-inflammatory and nociceptive effects [2?]. A subfamily of class IIA PLA2s has been purified from the venoms of several viperid snakes, in which the Asp49 residue is replaced by Lys [5, 6]. These Ly49-PLA2s conserve the basic structural fold of this family of enzymes but lack catalytic activity. While the Lys49-PLA2s do not show catalytic activity, in vitro studies showed they are able to disrupt liposome?The Author(s). 2017 Open Access This article is distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated.Zambelli et al. Journal of Venomous Animals and Toxins including Tropical Diseases (2017) 23:Page 2 ofmembranes and release their contents by a Ca2+-independent mechanism that does not involve hydrolysis of membrane phospholipids [7]. Despite the lack of catalytic activity, the in vivo activities of the Lys49-PLA2s include myonecrosis, bactericidal activity, local inflammation and pain [6, 8?3]. Chacur et al. [11] have demonstrated that the C-terminal cationic/hydrophobic sequence corresponding to amino acids 115?29 of a Linaprazan supplier Lys49-PLA2 isolated from Bothrops asper is critical for the sensation of pain. This finding is supported by the demonstration that heparin partially neutralizes hyperalgesia induced by this toxin, and the direct induction of hyperalgesia by the peptide corresponding to amino acids 115?29, although having lower activity than the native toxin. Despite this evidence, the amino acids responsible for PubMed ID:https://www.ncbi.nlm.nih.gov/pubmed/26024392 this effect are PubMed ID:https://www.ncbi.nlm.nih.gov/pubmed/28945807 unknown. Scanning alanine mutagenesis is a useful strategy to study the structural determinants of the activities of Lys49-PLA2. In this regard, Chioato et al. [14] have demonstrated that amino acid residues in C-terminal region of a Lys49-PLA2 from the venom of Bothrops jararacussu (BthTx-I) determine its biological activity. It has been demonstrated that the Lys122Ala mutant does not display myotoxic activity while Arg115Ala and Arg116Ala mutants do not display membrane-damaging activities. Moreover, His48Gln substitution, which eliminates any possible catalytic activity, does not influence the biological or membrane damaging proprieties of BthTx-I. Using these well-characterized functional point mutants in the activesite and C-terminal regions of the BthTx-I, we aimed to characterize the structural determinants for the Lys49PLA2-induced nociception and inflammation, and more specifically, the edematogenic response.performed by PCR mutagenesis [19] to introduce single mutations: Lys115 Ala (K115A), Lys116 Ala (K116A), Arg118 Ala (R118A), Lys122 Ala (K122A) and His48 Gln (H48Q). The final PCR reactions were performed using oligonucleotides complementary to the vector sequences flanking the BthTx-I insert which contained restriction sites for XbaI (5-extremity) and BamHI (3-extremity). After digestion with these enzymes, the ampli.

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