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| Registros recuperados: 19 | |
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| Domingues,Sarah J.S.; Souza,Thiago F. de; Soares,Alexandra M.S.; Jacinto,Tânia; Machado,Olga L.T.. |
| In order to investigate the defense response in castor bean (Ricinus communis) against predators, we analyzed the effect of mechanical wounding upon the phospholipase A2 (PLA2) activity of leaf extracts. Time course experiments revealed that the highest levels of increased PLA2 activity (ca. two fold) occurred 15 min and 60 min after injury. The induced activities demonstrated high sensitivity towards aristolochic acid (10 mM), a PLA2 inhibitor. Based on SDS-PAGE analysis, the PLA2 activity induced 15 min after wounding migrated with a molecular mass of 40 kDa and was denoted RcPLA2 I. The protein activity induced 60 min after wounding, RcPLA2 II, migrated with a molecular weight of 14 kDa. Furthermore its N-terminal sequence shared homology with PLA2 from... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Cellular defense; Castor bean; Plant signaling; Phospholipase A2; Ricinus communis. |
| Ano: 2007 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202007000100004 |
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| Leandro,Luís F.; Mendes,Carlos A.; Casemiro,Luciana A.; Vinholis,Adriana H.C.; Cunha,Wilson R.; Almeida,Rosana de; Martins,Carlos H.G.. |
| In this work, we used the Minimum Inhibitory Concentration (MIC) technique to evaluate the antibacterial potential of the apitoxin produced by Apis mellifera bees against the causative agents of tooth decay. Apitoxin was assayed in naturaand in the commercially available form. The antibacterial actions of the main components of this apitoxin, phospholipase A2, and melittin were also assessed, alone and in combination. The following bacteria were tested: Streptococcus salivarius, S. sobrinus, S. mutans, S. mitis, S. sanguinis, Lactobacillus casei, and Enterococcus faecalis. The MIC results obtained for the commercially available apitoxin and for the apitoxin in natura were close and lay between 20 and 40µg / mL, which indicated good antibacterial activity.... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Antibacterial activity; Apitoxin; Melittin; Phospholipase A2; Tooth decay; Oral pathogens. |
| Ano: 2015 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0001-37652015000100147 |
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| Cedro,Rafhaella C. A.; Menaldo,Danilo L.; Costa,Tássia R.; Zoccal,Karina F.; Sartim,Marco A.; Santos-Filho,Norival A.; Faccioli,Lúcia H.; Sampaio,Suely V.. |
| Abstract Background: Snake venom phospholipases A2 (PLA2s) have been reported to induce myotoxic, neurotoxic, hemolytic, edematogenic, cytotoxic and proinflammatory effects. This work aimed at the isolation and functional characterization of a PLA2 isolated from Bothrops jararaca venom, named BJ-PLA2-I. Methods and Results: For its purification, three consecutive chromatographic steps were used (Sephacryl S-200, Source 15Q and Mono Q 5/50 GL). BJ-PLA2-I showed acidic characteristics, with pI~4.4 and molecular mass of 14. 2 kDa. Sequencing resulted in 60 amino acid residues that showed high similarity to other Bothrops PLA2s, including 100% identity with BJ-PLA2, an Asp49 PLA2 previously isolated from B. jararaca venom. Being an Asp49 PLA2, BJ-PLA2-I... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Snake venom; Bothrops jararaca; Phospholipase A2; Inflammation; Cytotoxicity. |
| Ano: 2018 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1678-91992018000100324 |
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| Benati,Rogério Bodini; Costa,Tássia Rafaela; Cacemiro,Maira da Costa; Sampaio,Suely Vilela; Castro,Fabíola Attié de; Burin,Sandra Mara. |
| Abstract Background: Chronic myeloid leukemia (CML) is a BCR-ABL1+ myeloproliferative neoplasm marked by increased myeloproliferation and presence of leukemic cells resistant to apoptosis. The current first-line therapy for CML is administration of the tyrosine kinase inhibitors imatinib mesylate, dasatinib or nilotinib. Although effective to treat CML, some patients have become resistant to this therapy, leading to disease progression and death. Thus, the discovery of new compounds to improve CML therapy is still challenging. Here we addressed whether MjTX-I, a phospholipase A2 isolated from Bothrops moojeni snake venom, affects the viability of imatinib mesylate-resistant Bcr-Abl+ cell lines. Methods: We examined the cytotoxic and pro-apoptotic effect... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Chronic myeloid leukemia; Bcr-Abl; Phospholipase A2; MjTX-I; Bothrops moojeni; Apoptosis; Cytotoxicity. |
| Ano: 2018 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1678-91992018000100330 |
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| Bordon,Maria L. A. C.; Laurenti,Márcia D.; Ribeiro,Susan Pereira; Toyama,Marcos H.; Toyama,Daniela de O.; Passero,Luiz Felipe D.. |
| Abstract Background: Lipid metabolites play an important role in parasite differentiation and virulence. Studies have revealed that Leishmania sp. uses prostaglandins to evade innate barriers, thus enabling the parasites to survive inside immune cells. Despite the role of the enzyme Phospholipase A2 (PLA2) in prostaglandins production, few studies have investigated the role of parasite PLA2 during the interaction between L. (L.) amazonensis and the host (in vitro and in vivo) immune cells. Methods: In the present work, the leishmanicidal effect of PLA2 inhibitors, methyl arachidonyl fluorophosphonate (MAFP), bromoenol lactone (BEL) and aristolochic acid (AA) were investigated in vitro (promastigote and intracellular amastigote forms of L. (L.)... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Leishmania (Leishmania) amazonensis; Macrophages; BALB/c mice; Phospholipase A2; Phospholipase A2inhibitors. |
| Ano: 2018 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1678-91992018000100312 |
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| Sia,FY; Vejayan,J; Jamuna,A; Ambu,S. |
| In the present study, the effectiveness of Mimosa pudica tannins (MPT) in neutralizing the lethality of Naja kaouthia venom was compared with commercially derived tannins. Preincubation of MPT with N. kaouthia venom maintained 100% survival of mice after 24 hours. The mouse group in which there was no preincubation, no protection against the effects of the venom was observed. M. pudica tannin was found to be more effective in neutralizing the lethality of N. kaouthia venom when compared to commercial tannic acid. Two protein spots were missing in the two-dimensional gel electrophoresis (2-DE) of the MPT treated mouse indicating the down-regulation of venom proteins. The results from this study indicated that tannins obtained from M. pudica are better than... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Plant extract; Snake venom; Therapy; Tannin; Phospholipase A2. |
| Ano: 2011 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1678-91992011000100006 |
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| Campos,Patrícia Cota; Melo,Lutiana Amaral de; Dias,Gabriel Latorre Fortes; Fortes-Dias,Consuelo Latorre. |
| Abstract The blood plasma of numerous snake species naturally comprises endogenous phospholipase A2 inhibitors, which primarily neutralize toxic phospholipases A2 that may eventually reach their circulation. This inhibitor type is generally known as snake blood phospholipase A2 inhibitors (sbPLIs). Most, if not all sbPLIs are oligomeric glycosylated proteins, although the carbohydrate moiety may not be essential for PLA2 inhibition in every case. The presently known sbPLIs belong to one of three structural classes – namely sbαPLI, sbβPLI or sbγPLI – depending on the presence of characteristic C-type lectin-like domains, leucine-rich repeats or three-finger motifs, respectively. Currently, the most numerous inhibitors described in the literature are sbαPLIs... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: PLA2 inhibitor; Phospholipase A2; Snake blood; Natural resistance; Snakes. |
| Ano: 2016 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1678-91992016000100204 |
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| Fortes-Dias,Consuelo L.; Macedo,Diego Henrique Fagundes; Barbosa,Rafaella Pereira; Souza-Silva,Gabriel; Ortolani,Paula Ladeira. |
| Abstract Background: Endogenous phospholipase A2 inhibitors from snake blood (sbPLIs) have been isolated from several species around the world, with the primary function of self-protection against the action of toxic phospholipases A2. In American snakes, sbPLIs were solely described in pit vipers, in which the natural protection role is justified. In this study, we described a sbPLI in Boa constrictor (popularly known as jiboia), a non-venomous snake species from America. Methods: PLA2 inhibitory activity was tested in the blood plasma of B. constrictor using C. d. terrificus venom as the enzyme source. Antibodies developed against CNF, a sbγPLI from Crotalus durissus terrificus, were used to investigate the presence of homologues in the blood plasma... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Phospholipase A2 inhibitor; Phospholipase A2; Boidae; Snakes; Rattlesnake venom. |
| Ano: 2020 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1678-91992020000100305 |
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| Menaldo,Danilo L.; Jacob-Ferreira,Anna L.; Bernardes,Carolina P.; Cintra,Adélia C. O.; Sampaio,Suely V.. |
| Background Snake venoms are complex mixtures of inorganic and organic components, mainly proteins and peptides. Standardization of methods for isolating bioactive molecules from snake venoms is extremely difficult due to the complex and highly variable composition of venoms, which can be influenced by factors such as age and geographic location of the specimen. Therefore, this study aimed to standardize a simple purification methodology for obtaining a P-I class metalloprotease (MP) and an acidic phospholipase A2 (PLA 2 ) from Bothrops atroxvenom, and biochemically characterize these molecules to enable future functional studies.Methods To obtain the toxins of interest, a method has been standardized using consecutive isolation steps. The purity level of... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Snake venoms; Bothrops atrox; Toxins; Metalloprotease; Phospholipase A2; Isolation; Characterization; Chromatography. |
| Ano: 2015 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1678-91992015000100337 |
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| We describe the isolation of crotoxin, a presynaptic B-neurotoxin, as well as its subunits B (crotactine) and A (crotapotin) from lyophilized Crotalus durissus terrificus venom by a single-step preparative isoelectric focusing procedure. From 98 mg of dried venom protein 20.1 mg of crotactine and 13.1 mg of crotapotin were recovered in the first step of focalization and 4.2 mg in a second run. These values correspond to 35.7% of the total venom protein applied. Crotactine separated in the 9.3-7.0 pH range (tubes 1-6) and crotapotin in the 1.8-2.8 pH range (tubes 15-19) and both were homogeneous by SDS-PAGE and N-terminal amino acid analysis. Crotactine, a 12-kDa protein, presented hemolytic and phospholipase A2 activity. Thus, using isoelectric focusing we... |
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Palavras-chave: Crotalus durissus terrificus; Crotactine; Crotapotin; Phospholipase A2; Isoelectrofocusing; Presynaptic B-neurotoxin. |
| Ano: 1997 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X1997000100004 |
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| Borja-Oliveira,C.R.; Durigon,A.M.; Vallin,A.C.C.; Toyama,M.H.; Souccar,C.; Marangoni,S.; Rodrigues-Simioni,L.. |
| The neuromuscular effects of Bothrops neuwiedii pauloensis (jararaca-pintada) venom were studied on isolated chick biventer cervicis nerve-muscle preparations. Venom concentrations of 5-50 µg/ml produced an initial inhibition and a secondary increase of indirectly evoked twitches followed by a progressive concentration-dependent and irreversible neuromuscular blockade. At venom concentrations of 1-20 µg/ml, the responses to 13.4 mM KCl were inhibited whereas those to 110 µM acetylcholine alone and cumulative concentrations of 1 µM to 10 mM were unaffected. At venom concentrations higher than 50 µg/ml, there was pronounced muscle contracture with inhibition of the responses to acetylcholine, KCl and direct stimulation. At 20-24ºC, the venom (50 µg/ml)... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Chick biventer cervicis; Myotoxicity; Neurotoxicity; Phospholipase A2; Presynaptic action. |
| Ano: 2003 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2003000500009 |
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| Sousa,Paulo César P; Brito,Teresinha S; Freire,Daniel S; Ximenes,Rafael M; Magalhães,Pedro Jorge C; Monteiro,Helena SA; Alves,Renata S; Martins,Alice Maria C; Toyama,Daniela O; Toyama,Marcos H. |
| Background : Apis mellifera stings are a problem for public health worldwide, particularly in Latin America due to the aggressiveness of its Africanized honeybees. Massive poisoning by A. mellifera venom (AmV) affects mainly the cardiovascular system, and several works have described its actions on heart muscle. Nevertheless, no work on the pharmacological action mechanisms of the AmV in isolated aorta has been reported. Thus, the present work aimed to investigate the actions of AmV and its main fractions, phospholipase A2 (PLA2) and melittin, on isolated aorta rings and a probable action mechanism. Results : AmV and the complex PLA2 + melittin (0.1-50 μg/mL) caused contraction in endothelium-containing aorta rings, but neither isolated PLA2 nor melittin... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Apis mellifera; Venom; Mellitin; Phospholipase A2; Aorta. |
| Ano: 2013 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1678-91992013000100314 |
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| Registros recuperados: 19 | |
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