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1.
Glycoconj J ; 40(1): 85-95, 2023 02.
Artigo em Inglês | MEDLINE | ID: mdl-36287345

RESUMO

The Dalbergieae lectin group encompasses several lectins with significant differences in their carbohydrate specificities and biological properties. The current work reports on the purification and characterization of a GalNAc/Gal-specific lectin from Vataireopsis araroba (Aguiar) Ducke, designated as VaL. The lectin was purified from the seeds in a single step using guar gum affinity chromatography. The lectin migrated as a single band of about 35 kDa on SDS-PAGE and, in native conditions, occurs as a homodimer. The purified lectin is stable at temperatures up to 60 °C and in a pH range from 7 to 8 and requires divalent cations for its activity. Sugar-inhibition assays demonstrate the lectin specificity towards N-acetyl-D-galactosamine, D-galactose and related sugars. Furthermore, glycan array analyses show that VaL interacts preferentially with glycans containing terminal GalNAc/Galß1-4GlcNAc. Biological activity assays were performed using three insect cell lines: CF1 midgut cells from the spruce budworm Choristoneura fumiferana, S2 embryo cells from the fruit fly Drosophila melanogaster, and GutAW midgut cells from the corn earworm Helicoverpa zea. In vitro assays indicated a biostatic effect for VaL on CF1 cells, but not on S2 and GutAW cells. The lectin presented a biostatic effect by reducing the cell growth and inducing cell agglutination, suggesting an interaction with glycans on the cell surface. VaL has been characterized as a galactoside-specific lectin of the Dalbergieae tribe, with sequence similarity to lectins from Vatairea and Arachis.


Assuntos
Fabaceae , Lectinas , Animais , Lectinas/metabolismo , Fabaceae/química , Fabaceae/metabolismo , Drosophila melanogaster , Carboidratos/análise , Sementes/química , Polissacarídeos/metabolismo , Galactosídeos/análise , Galactosídeos/metabolismo , Lectinas de Plantas/química
2.
Glycoconj J ; 40(1): 47-67, 2023 02.
Artigo em Inglês | MEDLINE | ID: mdl-36522582

RESUMO

Glioblastoma multiforme (GBM) is the most aggressive type of glioma, displaying atypical glycosylation pattern that may modulate signaling pathways involved in tumorigenesis. Lectins are glycan binding proteins with antitumor properties. The present study was designed to evaluate the antitumor capacity of the Dioclea reflexa lectin (DrfL) on glioma cell cultures. Our results demonstrated that DrfL induced morphological changes and cytotoxic effects in glioma cell cultures of C6, U-87MG and GBM1 cell lines. The action of DrfL was dependent upon interaction with glycans, and required a carbohydrate recognition domain (CRD), and the cytotoxic effect was apparently selective for tumor cells, not altering viability and morphology of primary astrocytes. DrfL inhibited tumor cell migration, adhesion, proliferation and survival, and these effects were accompanied by activation of p38MAPK and JNK (p46/54), along with inhibition of Akt and ERK1/2. DrfL also upregulated pro-apoptotic (BNIP3 and PUMA) and autophagic proteins (Atg5 and LC3 cleavage) in GBM cells. Noteworthy, inhibition of autophagy and caspase-8 were both able to attenuate cell death in GBM cells treated with DrfL. Our results indicate that DrfL cytotoxicity against GBM involves modulation of cell pathways, including MAPKs and Akt, which are associated with autophagy and caspase-8 dependent cell death.


Assuntos
Antineoplásicos , Morte Celular Autofágica , Dioclea , Glioma , Humanos , Dioclea/química , Caspase 8/metabolismo , Caspase 8/farmacologia , Caspase 8/uso terapêutico , Lectinas/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Proteínas Proto-Oncogênicas c-akt/farmacologia , Proteínas Proto-Oncogênicas c-akt/uso terapêutico , Linhagem Celular Tumoral , Glioma/tratamento farmacológico , Glioma/metabolismo , Glioma/patologia , Movimento Celular , Autofagia , Antineoplásicos/farmacologia , Proliferação de Células , Apoptose
3.
Glycoconj J ; 39(5): 599-608, 2022 10.
Artigo em Inglês | MEDLINE | ID: mdl-35239112

RESUMO

Lectins isolated from Canavalia ensiformis (ConA) and Canavalia brasiliensis (ConBr) are promising molecules to prevent cell death. Acute pancreatitis, characterized by acinar cell necrosis and inflammation, presents significant morbidity and mortality. This study has investigated the effects of ConA and ConBr in experimental acute pancreatitis and pancreatic acinar cell death induced by bile acid. Pancreatitis was induced by retrograde pancreatic ductal injection of 3% sodium taurocholate (Na-TC) in male Swiss mice. ConA or ConBr (0.1, 1 or 10 mg/kg) were intravenously applied to mice 1 h and 12 h after induction. After 24 h, the severity of pancreatitis was evaluated by serum amylase and lipase, histopathological changes and myeloperoxidase assay. Pancreatic acinar cells were incubated with ConA (200 µg/ml) or ConBr (200 µg/ml) and taurolithocholic acid 3-sulfate (TLCS; 500 µM). Necrosis and changes in mitochondrial membrane potential (ΔÑ°m) were detected by fluorescence confocal microscopy. Treatment (post-insult) with ConA and ConBr decreased pancreatic damage caused by retrograde injection of Na-TC in mice, reducing pancreatic neutrophil infiltration, edema and necrosis. In addition, ConA and ConBr decreased pancreatic acinar cell necrosis and depolarization of ΔÑ°m caused by TLCS. The inhibition of necrosis was prevented by the lectin domain blockade. In conclusion, ConA and ConBr markedly inhibited in vitro and in vivo damage, effects partly dependent on the interaction with mannose residues on acinar cells. These data support the potential application of these proteins for treatment of acute pancreatitis.


Assuntos
Canavalia , Pancreatite , Doença Aguda , Animais , Anti-Inflamatórios , Canavalia/química , Lectinas/farmacologia , Masculino , Camundongos , Necrose/tratamento farmacológico , Pancreatite/induzido quimicamente , Pancreatite/tratamento farmacológico , Lectinas de Plantas/química , Sementes/química
4.
Mol Biol Rep ; 49(9): 8847-8857, 2022 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-35882745

RESUMO

OBJECTIVE: To investigate the effect and mechanisms of Andira anthelmia lectin in rat models of acute inflammation. MATERIAL: AAL anti-inflammatory activity was evaluated in Wistar rat models of paw edema and peritonitis. METHODS: AAL (0.01-1 mg/kg i.v.) was injected 30 min before stimulation with carrageenan and with initial and late phase inflammatory mediators into the animals paw or peritoneum for evaluation of cell migration (optical and intravital microscopy), paw edema (plethysmometry and histopathology); hyperalgesia (analgesimetry). RESULTS: AAL inhibited leukocyte migration induced by carrageenan, mainly neutrophils to the peritoneal fluid, decreasing leukocyte adhesion. In the peritoneal fluid, AAL reduced the gene expression of TNF-α and cyclooxygenase, as well the levels of PGE2. AAL inhibited the paw edema induced by carrageenan, serotonin, histamine, TNF-α, PLA2 and PGE2, but not by L-arginine. In this model, AAL also inhibited mechanical hypernociception induced by TNF-α, PGE2, db-cAMP and capsaicin, and the activity of myeloperoxidase in the paw tissues. CONCLUSION: AAL presents anti-inflammatory effect in acute models of rat inflammation involving the participation of prostaglandins, TNF-α and lectin domain.


Assuntos
Fabaceae , Fator de Necrose Tumoral alfa , Animais , Anti-Inflamatórios/farmacologia , Anti-Inflamatórios/uso terapêutico , Carragenina , Dinoprostona/metabolismo , Edema/induzido quimicamente , Edema/tratamento farmacológico , Edema/patologia , Fabaceae/metabolismo , Inflamação/patologia , Lectinas , Prostaglandinas , Ratos , Ratos Wistar
5.
Molecules ; 27(20)2022 Oct 20.
Artigo em Inglês | MEDLINE | ID: mdl-36296679

RESUMO

A glioblastoma (GBM) is a highly malignant primary brain tumor with a poor prognosis because of its invasiveness and high resistance to current therapies. In GBMs, abnormal glycosylation patterns are associated with malignancy, which allows for the use of lectins as tools for recognition and therapy. More specifically, lectins can interact with glycan structures found on the malignant cell surface. In this context, the present work aimed to investigate the antiglioma potential of ConGF, a lectin purified from Canavalia grandiflora seeds, against C6 cells. The treatment of C6 cells with ConGF impaired the mitochondrial transmembrane potential, reduced cell viability, and induced morphological changes. ConGF also induced massive autophagy, as evaluated by acridine orange (AO) staining and LC3AB-II expression, but without prominent propidium iodide (PI) labeling. The mechanism of action appears to involve the carbohydrate-binding capacity of ConGF, and in silico studies suggested that the lectin can interact with the glycan structures of matrix metalloproteinase 1 (MMP1), a prominent protein found in malignant cells, likely explaining the observed effects.


Assuntos
Canavalia , Fabaceae , Canavalia/química , Fabaceae/química , Lectinas/química , Metaloproteinase 1 da Matriz , Propídio , Laranja de Acridina , Lectinas de Plantas/química , Sementes/química , Carboidratos/análise
6.
J Mol Recognit ; 34(10): e2922, 2021 10.
Artigo em Inglês | MEDLINE | ID: mdl-34132435

RESUMO

Using a rat model of peritonitis, we herein report the inflammatory effect induced by the lectin isolated from Vatairea guianensis (VGL) seeds in the context of interactions between VGL and both toll-like receptor 4 (TLR4) and tumor necrosis factor receptor 1 (TNFR1). Peritoneal macrophages were stimulated with VGL for dose-dependent gene expression and release of TNF-α. In vivo results showed that VGL (1 mg/kg; intraperitoneal) induced peritonitis in female Wistar rats. Leukocyte migration, macrophage activation, and protein leakage were measured 3 and 6 hours after induction. In vitro, peritoneal macrophages were stimulated with VGL for gene expression and TNF-α dosage (mean ± SEM (n = 6), analysis of variance, and Bonferroni's test (P < .05)). In silico, VGL structure was applied in molecular docking with representative glycans. It was found that (a) VGL increases vascular permeability and stimulates leukocyte migration, both rolling and adhesion; (b) lectin-induced neutrophil migration occurs via macrophage stimulation, both in vitro and in vivo; (c) lectin interacts with TLR4 and TNFR1; and (d) stimulates TNF-α gene expression (RT-PCR) and release from peritoneal macrophages. Thus, upon lectin-glycan binding on the cell surface, our results suggest that VGL induces an acute inflammatory response, in turn activating the release of peritoneal macrophages via TNF-α and TLR and/or TNFR receptor pathways.


Assuntos
Fabaceae/química , Glicoconjugados/metabolismo , Macrófagos Peritoneais/efeitos dos fármacos , Lectinas de Plantas/farmacologia , Animais , Movimento Celular/efeitos dos fármacos , Células Cultivadas , Modelos Animais de Doenças , Feminino , Regulação da Expressão Gênica/efeitos dos fármacos , Glicoconjugados/química , Leucócitos/efeitos dos fármacos , Macrófagos Peritoneais/metabolismo , Peritonite/induzido quimicamente , Peritonite/metabolismo , Peritonite/patologia , Lectinas de Plantas/química , Lectinas de Plantas/metabolismo , Ratos Wistar , Receptores Tipo I de Fatores de Necrose Tumoral/química , Receptores Tipo I de Fatores de Necrose Tumoral/metabolismo , Receptor 4 Toll-Like/metabolismo , Fator de Necrose Tumoral alfa/genética , Fator de Necrose Tumoral alfa/metabolismo
7.
Inflammopharmacology ; 28(6): 1623-1631, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-32572724

RESUMO

OBJECTIVE AND DESIGN: The involvement of nitric oxide pathway in the antinociceptive activity of Lonchocarpus araripensis lectin (LAL) was investigated in the model of carragenan-induced hypernociception. METHODS: Swiss mice received LAL (0.01-10 mg/kg; i.v.) 30 min before s.c. injection of carragenan in the paws. For the involvement of nociceptive pathways, animals were previously treated with the blockers: NOS (L-NAME, aminoguanidine, 7-nitroindazole); soluble guanylyl cyclase (ODQ); channels of ATP-dependent K+ (glibenclamide); L-type Ca2+ (nifedipine), or Ca2+-dependent Cl- (niflumic acid). Participation of lectin domain was evaluated by injection of LAL associated with N-acetyl-glucosamine (GlcNAc). nNOS gene relative expression was evaluated in the paw tissues and nNOS immunostaining in dorsal root ganglia. RESULTS: LAL at all doses inhibited carrageenan-induced hypernociception (4.12 ± 0.58 g), being maximal at 10 mg/kg (3 h: 59%), and reversed by GlcNAc. At this time, LAL effect was reversed by nifedipine (39%), niflumic acid (59%), L-NAME (59%), 7-nitroindazole (44%), ODQ (45%), and glibenclamide (34%), but was unaltered by aminoguanidine. LAL increased (95%) nNOS gene expression in mice paw tissues, but not its immunoexpression in the dorsal root ganglia. CONCLUSION: The antinociceptive effect of Lonchocarpus araripensis lectin involves activation of the L-arginine/NO/GMPc/K+ATP pathway.


Assuntos
Analgésicos/farmacologia , Arginina/metabolismo , GMP Cíclico/metabolismo , Fabaceae/química , Canais KATP/metabolismo , Lectinas/farmacologia , Óxido Nítrico/metabolismo , Transdução de Sinais/efeitos dos fármacos , Trifosfato de Adenosina/metabolismo , Animais , Carragenina/farmacologia , Gânglios Espinais/efeitos dos fármacos , Gânglios Espinais/metabolismo , Expressão Gênica/efeitos dos fármacos , Masculino , Camundongos , Óxido Nítrico Sintase Tipo I/metabolismo
9.
Arch Biochem Biophys ; 630: 27-37, 2017 09 15.
Artigo em Inglês | MEDLINE | ID: mdl-28754321

RESUMO

The Pisum arvense lectin (PAL), a legume protein belonging to the Vicieae tribe, is capable of specific recognition of mannose, glucose and its derivatives without altering its structure. In this work, the three-dimensional structure of PAL was determined by X-ray crystallography and studied in detail by a combination of molecular docking and molecular dynamics (MD). Crystals belonging to monoclinic space group P21 were grown by the vapor diffusion method at 293 K. The structure was solved at 2.16 Å and was similar to that of other Vicieae lectins. The structure presented Rfactor and Rfree of 17.04% and 22.08%, respectively, with all acceptable geometric parameters. Molecular docking was performed to analyze interactions of the lectin with monosaccharides, disaccharides and high-mannose N-glycans. PAL demonstrated different affinities on carbohydrates, depending on bond orientation and glycosidic linkage present in ligands. Furthermore, the lectin interacted with representative N-glycans in a manner consistent with the biological effects described for Vicieae lectins. Carbohydrate-recognition domain (CRD) in-depth analysis was performed by MD, describing the behavior of CRD residues in complex with ligand, stability, flexibility of the protein over time, CRD volume and topology. This is a first report of its kind for a lectin of the Vicieae tribe.


Assuntos
Fabaceae/química , Simulação de Acoplamento Molecular , Simulação de Dinâmica Molecular , Lectinas de Plantas/química , Polissacarídeos/química , Cristalografia por Raios X
10.
J Mol Recognit ; 29(6): 248-52, 2016 06.
Artigo em Inglês | MEDLINE | ID: mdl-26638121

RESUMO

Andira anthelmia (tribe Dalbergieae), a plant from Brazilian Amazon, possesses a seed lectin that was purified by affinity chromatography in sepharose-mannose. This novel Dalbergieae lectin, named AAL, agglutinated rabbit erythrocytes treated with trypsin. The hemagglutinating activity of AAL was maintained after incubation at a wide range of temperature (40 to 70 °C) and pH, was shown to be dependent on divalent cations, and was inhibited by d-mannose and d-sucrose. AAL showed an electrophoretic profile in sodium dodecyl sulfate-polyacrylamide gel electrophoresis similar to other lectins of the tribe Dalbergieae, presenting a double band of molecular weight with approximately 20 kDa and other minor bands of 17, 15, and 13 kDa, being the smaller fragment glycosylated. AAL injected by intravenous route in mice showed antinociceptive activity in two behavioral tests (writhing and formalin). In the writhing test induced by acetic acid, AAL showed inhibitory effect at 0.01 mg/kg (68%), 0.1 mg/kg (46%) and 1 mg/kg (74%). In the formalin test, AAL (0.1 mg/kg) inhibited by 48% the licking time in the inflammatory phase, an effect that was recovered by the lectin association with mannose. In conclusion, AAL presents analgesic effect involving the lectin domain via peripheral mechanisms of inflammatory nociception. This activity highlights the importance of lectins as tools to be used for understanding the interaction of protein-carbohydrate in processes associated to inflammatory pain. Copyright © 2015 John Wiley & Sons, Ltd.


Assuntos
Analgésicos/administração & dosagem , Analgésicos/isolamento & purificação , Fabaceae/química , Dor/tratamento farmacológico , Lectinas de Plantas/administração & dosagem , Lectinas de Plantas/isolamento & purificação , Analgésicos/química , Analgésicos/farmacologia , Animais , Cromatografia de Afinidade , Modelos Animais de Doenças , Relação Dose-Resposta a Droga , Eritrócitos/efeitos dos fármacos , Testes de Hemaglutinação , Concentração de Íons de Hidrogênio , Manose/farmacologia , Camundongos , Peso Molecular , Dor/etiologia , Lectinas de Plantas/química , Lectinas de Plantas/farmacologia , Estabilidade Proteica , Coelhos , Sacarose/farmacologia , Temperatura
11.
Arch Biochem Biophys ; 596: 73-83, 2016 04 15.
Artigo em Inglês | MEDLINE | ID: mdl-26946944

RESUMO

A glycosylated lectin (CTL) with specificity for mannose and glucose has been detected and purified from seeds of Centrolobium tomentosum, a legume plant from Dalbergieae tribe. It was isolated by mannose-sepharose affinity chromatography. The primary structure was determined by tandem mass spectrometry and consists of 245 amino acids, similar to other Dalbergieae lectins. CTL structures were solved from two crystal forms, a monoclinic and a tetragonal, diffracted at 2.25 and 1.9 Å, respectively. The carbohydrate recognition domain (CRD), metal-binding site and glycosylation site were characterized, and the structural basis for mannose/glucose-binding was elucidated. The lectin adopts the canonical dimeric organization of legume lectins. CTL showed acute inflammatory effect in paw edema model. The protein was subjected to ligand screening (dimannosides and trimannoside) by molecular docking, and interactions were compared with similar lectins possessing the same ligand specificity. This is the first crystal structure of mannose/glucose native seed lectin with proinflammatory activity isolated from the Centrolobium genus.


Assuntos
Edema/induzido quimicamente , Fabaceae/química , Lectina de Ligação a Manose , Simulação de Acoplamento Molecular , Lectinas de Plantas , Sementes/química , Sequência de Aminoácidos , Animais , Modelos Animais de Doenças , Edema/patologia , Feminino , Glicosilação , Inflamação/induzido quimicamente , Inflamação/patologia , Lectina de Ligação a Manose/química , Lectina de Ligação a Manose/toxicidade , Espectrometria de Massas , Lectinas de Plantas/química , Lectinas de Plantas/toxicidade , Pegadas de Proteínas , Ratos , Ratos Wistar , Relação Estrutura-Atividade
12.
Inflamm Res ; 65(9): 701-8, 2016 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-27193121

RESUMO

OBJECTIVE AND DESIGN: Sodium channels are highly expressed in nociceptive sensory neurons during hypernociceptive conditions. Based on the presence of a glycosidic portion in the sodium channel ß subunit associated to the antinociceptive effect of leguminous lectins via lectin domain, this study investigated the antinociceptive activity of the lectin isolated from Lonchocarpus araripensis seeds (LAL) in mice behavioral models and in NaV current in the nociceptor of rat dorsal root ganglion (DRG). MATERIAL/METHODS: LAL antinociceptive activity and the participation of opioid system, lectin domain and sodium channels were evaluated in Swiss mice models of nociception (formalin, capsaicin, hot plate, tail flick, von Frey) and in primary cultures of Wistar rats neurons of DRG (patch clamp). RESULTS: LAL presented inhibitory effects in the nociception induced by chemical and mechanical, but not by thermal stimuli and reduced total Na(+) current. LAL activity was inhibited by the lectin association with its binding sugar N-acethyl-glucosamine. CONCLUSION: LAL inhibits peripheral hypernociception by mechanisms that involve the lectin domain, inflammatory mediators and Na(+) channels. The innovative inhibitory action of leguminous lectins on NaV current brings new insights for the investigation of sodium channels role in nociception.


Assuntos
Analgésicos , Fabaceae , Lectinas , Dor/tratamento farmacológico , Canais de Sódio/fisiologia , Analgésicos/farmacologia , Analgésicos/uso terapêutico , Animais , Capsaicina , Formaldeído , Gânglios Espinais/efeitos dos fármacos , Gânglios Espinais/fisiologia , Temperatura Alta , Lectinas/farmacologia , Lectinas/uso terapêutico , Masculino , Camundongos , Neurônios/efeitos dos fármacos , Neurônios/fisiologia , Nociceptividade/efeitos dos fármacos , Estimulação Física , Ratos Wistar , Sementes
13.
Arch Biochem Biophys ; 588: 33-40, 2015 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-26545483

RESUMO

A novel lectin from seeds of Clathrotropis nitida (CNA) was purified and characterized. CNA is a glycoprotein containing approximately 3.3% carbohydrates in its structure. CNA promoted intense agglutination of rabbit erythrocytes, which was inhibited by galactosides and porcine stomach mucin (PSM). The lectin maintained its hemagglutinating activity after incubation in a wide range of temperatures (30-60 °C) and pH (6.0-7.0), and its binding activity was dependent on divalent cations (Ca(+2) and Mg(+2)). SDS-PAGE showed an electrophoretic profile consisting of a single band of 28 kDa, as confirmed by electrospray ionization mass spectrometry, which indicated an average molecular mass of 27,406 ± 2 Da and the possible presence of isoforms and glycoforms. In addition, CNA exhibited no toxicity to Artemia sp. nauplii and elicited reversible and dose-dependent vasorelaxation in precontracted aortic rings. CNA was successfully immobilized on chitosan beads and was able to capture PSM in solution. This study demonstrated that CNA is a lectin that has potential as a biotechnological tool in glycomics and glycoproteomics applications.


Assuntos
Fabaceae/química , Lectinas de Plantas/isolamento & purificação , Lectinas de Plantas/farmacologia , Vasodilatadores/isolamento & purificação , Vasodilatadores/farmacologia , Sequência de Aminoácidos , Animais , Aorta Torácica/efeitos dos fármacos , Aorta Torácica/fisiologia , Artemia/efeitos dos fármacos , Quitosana , Fabaceae/genética , Hemaglutinação/efeitos dos fármacos , Humanos , Proteínas Imobilizadas/química , Técnicas In Vitro , Masculino , Dados de Sequência Molecular , Peso Molecular , Lectinas de Plantas/genética , Plantas Medicinais/química , Plantas Medicinais/genética , Coelhos , Ratos , Ratos Wistar , Sementes/química , Homologia de Sequência de Aminoácidos , Vasodilatadores/química
14.
Arch Biochem Biophys ; 543: 31-9, 2014 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-24361256

RESUMO

Lectins are comprised of a large family of proteins capable of the specific and reversible recognition of carbohydrates. Legume lectins, the most studied plant lectins, show high structural similarity, but with modifications that imply a variation in the intensity of some biological activities. In this work, the primary and tertiary structures of Canavalia grandiflora (ConGF) were determined. ConGF, a lectin isolated from C. grandiflora seeds, is able to induce relaxant activity in rat aortic rings. The complete sequence of ConGF comprises 237 amino acids. This particular protein has primary sequence variations commonly found in lectins from Dioclea and Canavalia genera. The protein structure was solved at 2.3 Å resolution by X-ray crystallography. An X-Man molecule was modeled into the carbohydrate recognition domain. Still, ConGF (30 and 100 µg mL(-1)) elicited 25% of vasorelaxation (IC50=34.48 ± 5.07 µg mL(-1)) in endothelialized aortic rings. A nonselective inhibitor of nitric oxide blocked ConGF relaxant effect, showing mediation by nitric oxide. Key distances between ConGF carbohydrate recognition domain residues were determined in order to explain this effect, in turn revealing some structural aspects that could differentiate lectins from the Canavalia genera with respect to different efficacy in vasorelaxant effect.


Assuntos
Lectinas de Plantas/química , Lectinas de Plantas/farmacologia , Vasodilatadores/química , Vasodilatadores/farmacologia , Sequência de Aminoácidos , Animais , Sítios de Ligação , Técnicas In Vitro , Masculino , Manose/química , Manose/metabolismo , Espectrometria de Massas , Modelos Moleculares , Dados de Sequência Molecular , Lectinas de Plantas/metabolismo , Estabilidade Proteica , Estrutura Terciária de Proteína , Ratos , Ratos Wistar , Análise de Sequência , Relação Estrutura-Atividade , Vasodilatadores/metabolismo
15.
ScientificWorldJournal ; 2014: 239208, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-25431778

RESUMO

Leishmaniasis is a vector-borne disease transmitted by phlebotomine sand fly. Susceptibility and refractoriness to Leishmania depend on the outcome of multiple interactions that take place within the sand fly gut. Promastigote attachment to sand fly midgut epithelium is essential to avoid being excreted together with the digested blood meal. Promastigote and gut sand fly surface glycans are important ligands in this attachment. The purpose of the present study was to evaluate the interaction of three lectins isolated from leguminous seeds (Diocleinae subtribe), D-glucose and D-mannose-binding, with glycans on Lutzomyia migonei midgut. To study this interaction the lectins were labeled with FITC and a fluorescence assay was performed. The results showed that only Dioclea violacea lectin (DVL) was able to interact with midgut glycans, unlike Cratylia floribunda lectin (CFL) and Canavalia gladiata lectin (CGL). Furthermore, when DVL was blocked with D-mannose the interaction was inhibited. Differences of spatial arrangement of residues and volume of carbohydrate recognition domain (CRD) may be the cause of the fine specificity of DVL for glycans in the surface on Lu. migonei midgut. The findings in this study showed the presence of glycans in the midgut with glucose/mannose residues in its composition and these residues may be important in interaction between Lu. migonei midgut and Leishmania.


Assuntos
Canavalia , Dioclea , Absorção Gastrointestinal/fisiologia , Lectinas de Plantas/metabolismo , Psychodidae , Animais , Lectinas/isolamento & purificação , Lectinas/metabolismo , Lectinas de Plantas/isolamento & purificação , Sementes
16.
J Mol Recognit ; 26(1): 51-8, 2013 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-23280618

RESUMO

Two new lectins named Halilectin 1 (H-1) and Halilectin 2 (H-2) were isolated from the marine sponge Haliclona caerulea using a combination of affinity chromatography on stroma fixed onto Sephadex G-25 and cation and anion exchange chromatography. H-1 is a monomeric protein with a molecular mass of 40 kDa estimated using sodium dodecyl sulfate polyacrylamide gel electrophoresis and 15 kDa estimated using a TSK gel. Conversely, H-2 is a homodimeric protein with 15 kDa monomers linked via weak interactions. H-1 more effectively agglutinates trypsinized rabbit erythrocytes, whereas H-2 more effectively agglutinates native rabbit erythrocytes. The hemagglutinating activity of H-1 could be not inhibited by any tested sugars, but H-2 was inhibited by orosomucoid and porcine stomach mucin. Neither lectin was dependent on divalent ions. H-1 was stable at basic pH range and temperatures up to 50 °C, whereas H-2 was stable at acid pH range and temperatures up to 80 °C. The H. caerulea lectins exhibited dose-dependent toxicity against Artemia nauplii. Additionally, 76% of the primary structure of H-2 was determined using tandem mass spectrometry to contain a unique amino acid sequence with no similarity to any members of the animal lectin family.


Assuntos
Haliclona/química , Lectinas/química , Lectinas/farmacologia , Poríferos/química , Sequência de Aminoácidos , Animais , Artemia/efeitos dos fármacos , Sequência de Bases , Cromatografia/métodos , Eritrócitos/efeitos dos fármacos , Hemaglutinação/efeitos dos fármacos , Testes de Hemaglutinação/métodos , Concentração de Íons de Hidrogênio , Dados de Sequência Molecular , Peso Molecular , Coelhos , Espectrometria de Massas em Tandem/métodos , Temperatura
17.
J Nanosci Nanotechnol ; 13(8): 5276-82, 2013 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-23882754

RESUMO

We evaluated local inflammatory activity of oxidized multiwalled carbon nanotubes in rat experimental models of acute inflammation (paw edema and hyperalgesia) by analyzing their toxicity in non-mesoendothelial tissues. Subcutaneous injection of the nanotubes induced paw edema, that was maximal in the first 2 h after administration at 0.1 mg/kg (43.25 +/- 3.8 AUC) and 1 mg/kg (30.1 +/- 1.8 AUC) compared to saline (18.32 +/- 02.05 AUC). The histopathological analysis showed acute inflammation characterized by vasodilatation, edema formation, neutrophil infiltrate and tissue damage. The nanotubes also elicited hyperalgesic response, seen by the increase of animal paw withdrawal that was maximal in the first 3 hours. The data obtained at the 3rd h was: 75 +/- 9.3% (0.01 mg/kg), 58 +/- 8.3% (0.1 mg/kg) and 53 +/- 6.69% (1 mg/kg) in relation with saline (28 +/- 3.5%). In conclusion, the oxidized multiwalled carbon nanotubes elicit inflammatory and hyperalgesic effects associated to severe tissue damage in rats.


Assuntos
Hiperalgesia/metabolismo , Inflamação/tratamento farmacológico , Nanotecnologia/métodos , Nanotubos de Carbono/química , Oxigênio/química , Animais , Área Sob a Curva , Edema/patologia , Hiperalgesia/tratamento farmacológico , Masculino , Neutrófilos/metabolismo , Ratos , Ratos Wistar , Fatores de Tempo
18.
Molecules ; 18(5): 5792-803, 2013 May 17.
Artigo em Inglês | MEDLINE | ID: mdl-23685936

RESUMO

Rhizobium tropici is a Gram-negative bacterium that induces nodules and fixed atmospheric nitrogen in symbiotic association with Phaseolus vulgaris (common bean) and some other leguminous species. Lectins are proteins that specifically bind to carbohydrates and, consequently, modulate different biological functions. In this study, the d-glucose/ d-mannose-binding lectins (from seeds of Dioclea megacarpa, D. rostrata and D. violacea) and D-galactose-binding lectins (from seeds of Bauhinia variegata, Erythina velutina and Vatairea macrocarpa) were purified using chromatographic techniques and evaluated for their effect on the growth of R. tropici CIAT899. All lectins were assayed with a satisfactory degree of purity according to SDS-PAGE analysis, and stimulated bacterial growth; in particular, the Dioclea rostrata lectin was the most active among all tested proteins. As confirmed in the present study, both d-galactose- and d-glucose/d-mannose-binding lectins purified from the seeds of leguminous plants may be powerful biotechnological tools to stimulate the growth of R. tropici CIAT99, thus improving symbiotic interaction between rhizobia and common bean and, hence, the production of this field crop.


Assuntos
Fabaceae/química , Lectinas de Plantas , Rhizobium tropici/crescimento & desenvolvimento , Sementes/química , Lectinas de Plantas/química , Lectinas de Plantas/isolamento & purificação , Lectinas de Plantas/farmacologia
19.
Molecules ; 18(9): 10857-69, 2013 Sep 04.
Artigo em Inglês | MEDLINE | ID: mdl-24008245

RESUMO

Lectin from the seeds of Dioclea lasiophylla (DlyL) was purified in a single step by affinity chromatography on a Sephadex® G-50 column. DlyL strongly agglutinated rabbit erythrocytes and was inhibited by monosaccharides (D-mannose and α-methyl-D-mannoside) and glycoproteins (ovalbumin and fetuin). Similar to other Diocleinae lectins, DlyL has three chains, α, ß and γ, with mass of 25,569 ± 2, 12,998 ± 1 and 12,588 ± 1 Da, respectively, and has no disulfide bonds. The hemagglutinating activity of DlyL was optimal in pH 8.0, stable at a temperature of 70 °C and decreased in EDTA solution, indicating that lectin activity is dependent on divalent metals. DlyL exhibited low toxicity on Artemia sp. nauplii, but this effect was dependent on the concentration of lectin in solution. DlyL immobilized on cyanogen bromide-activated Sepharose® 4B bound 0.917 mg of ovalbumin per cycle, showing the ability to become a tool for glycoproteomics studies.


Assuntos
Dioclea/química , Hemaglutininas/farmacologia , Lectinas de Ligação a Manose/farmacologia , Extratos Vegetais/farmacologia , Sementes/química , Animais , Artemia , Quelantes/química , Cromatografia de Afinidade , Ácido Edético/química , Eritrócitos/efeitos dos fármacos , Hemaglutinação , Hemaglutininas/química , Hemaglutininas/isolamento & purificação , Concentração de Íons de Hidrogênio , Dose Letal Mediana , Lectinas de Ligação a Manose/química , Lectinas de Ligação a Manose/isolamento & purificação , Ovalbumina/química , Extratos Vegetais/química , Extratos Vegetais/isolamento & purificação , Ligação Proteica , Coelhos , Sefarose/química
20.
Biochimie ; 208: 100-116, 2023 May.
Artigo em Inglês | MEDLINE | ID: mdl-36586566

RESUMO

Poor lifestyle choices and genetic predisposition are factors that increase the number of cancer cases, one example being breast cancer, the third most diagnosed type of malignancy. Currently, there is a demand for the development of new strategies to ensure early detection and treatment options that could contribute to the complete remission of breast tumors, which could lead to increased overall survival rates. In this context, the glycans observed at the surface of cancer cells are presented as efficient tumor cell markers. These carbohydrate structures can be recognized by lectins which can act as decoders of the glycocode. The application of plant lectins as tools for diagnosis/treatment of breast cancer encompasses the detection and sorting of glycans found in healthy and malignant cells. Here, we present an overview of the most recent studies in this field, demonstrating the potential of lectins as: mapping agents to detect differentially expressed glycans in breast cancer, as histochemistry/cytochemistry analysis agents, in lectin arrays, immobilized in chromatographic matrices, in drug delivery, and as biosensing agents. In addition, we describe lectins that present antiproliferative effects by themselves and/or in conjunction with other drugs in a synergistic effect.


Assuntos
Neoplasias da Mama , Fabaceae , Humanos , Feminino , Lectinas/química , Neoplasias da Mama/diagnóstico , Neoplasias da Mama/tratamento farmacológico , Polissacarídeos/química , Lectinas de Plantas , Verduras , Biomarcadores Tumorais
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