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1.
Curr Res Struct Biol ; 7: 100140, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38559841

RESUMO

The mechanisms behind Concanavalin A (ConA) circular permutation have been under investigation since 1985. Although a vast amount of information is available about this lectin and its applications, the exact purpose of its processing remains unclear. To shed light on this, this study employed computer simulations to compare the unprocessed ProConA with the mature ConA. This approach aimed to reveal the importance of the post-translational modifications, especially how they affect the lectin stability and carbohydrate-binding properties. To achieve these goals, we conducted 200 ns molecular dynamics simulations and trajectory analyses on the monomeric forms of ProConA and ConA (both unbound and in complex with D-mannose and the GlcNAc2Man9 N-glycan), as well as on their oligomeric forms. Our findings reveal significant stability differences between ProConA and ConA at both the monomeric and tetrameric levels, with ProConA exhibiting consistently lower stability parameters compared to ConA. In terms of carbohydrate binding properties, however, both lectins showed remarkable similarities in their interaction profiles, contact numbers, and binding free energies with D-mannose and the high-mannose N-glycan. Overall, our results suggest that the processing of ProConA significantly enhances the stability of the mature lectin, especially in maintaining the tetrameric oligomer, without substantially affecting its carbohydrate-binding properties.

2.
Int J Mol Sci ; 24(21)2023 Nov 04.
Artigo em Inglês | MEDLINE | ID: mdl-37958949

RESUMO

Cells use glycans to encode information that modulates processes ranging from cell-cell recognition to programmed cell death. This information is encoded within a glycocode, and its decoding is performed by carbohydrate-binding proteins. Among these, lectins stand out due to their specific and reversible interaction with carbohydrates. Changes in glycosylation patterns are observed in several pathologies, including cancer, where abnormal glycans are found on the surfaces of affected tissues. Given the importance of the bioprospection of promising biomolecules, the current work aimed to determine the structural properties and anticancer potential of the mannose-specific lectin from seeds of Canavalia villosa (Cvill). Experimental elucidation of the primary and 3D structures of the lectin, along with glycan array and molecular docking, facilitated the determination of its fine carbohydrate-binding specificity. These structural insights, coupled with the lectin's specificity, have been combined to explain the antiproliferative effect of Cvill against cancer cell lines. This effect is dependent on the carbohydrate-binding activity of Cvill and its uptake in the cells, with concomitant activation of autophagic and apoptotic pathways.


Assuntos
Canavalia , Lectinas , Lectinas/farmacologia , Lectinas/análise , Canavalia/metabolismo , Simulação de Acoplamento Molecular , Lectinas de Plantas/metabolismo , Sementes/metabolismo , Carboidratos/análise , Polissacarídeos/análise
3.
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
4.
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
5.
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
6.
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
7.
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
8.
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
9.
Int J Biol Macromol ; 199: 243-251, 2022 Feb 28.
Artigo em Inglês | MEDLINE | ID: mdl-35016969

RESUMO

The lack of specific pharmacological therapy for Autistic Spectrum Disorder (ASD) and its clinical heterogeneity demand efforts directed toward the identification of biomarkers to aid in diagnosis. Proteomics offers a new perspective for studying the altered proteins associated with autism spectrum disorders (ASD) and we have saliva as an easy-to-collect biological fluid with important biomolecules for investigating biomarkers in various diseases. In this sense, saliva could be used to identify potential biomarkers of ASD. In the current work, saliva samples were collected from children with different degrees of ASD and healthy children and proteomics approaches were applied to generate data on differentially expressed proteins between groups which will serve as a basis for future validation studies as protein markers. Data are available via ProteomeXchange with identifier PXD030065. As results, 132 proteins were present in 80% of the saliva pools of all analyzed groups. Twenty-five proteins were identified as overexpressed in the group of severe and mild/moderate ASD carriers, among which, eight were identified as potential biomarkers for ASD.


Assuntos
Transtorno do Espectro Autista , Proteômica , Transtorno do Espectro Autista/diagnóstico , Transtorno do Espectro Autista/metabolismo , Biomarcadores/metabolismo , Criança , Humanos , Saliva/metabolismo
10.
J Biomol Struct Dyn ; 40(15): 6817-6830, 2022 09.
Artigo em Inglês | MEDLINE | ID: mdl-33616012

RESUMO

Lectins are a class of proteins or glycoproteins capable of recognizing and interacting with carbohydrates in a specific and reversible manner. Owing to this property, these proteins can interact with glycoconjugates present on the cell surface, making it possible to decipher the glycocode, as well as elicit biological effects, such as inflammation and vasorelaxation. Here, we report a structural and biological study of the mannose/glucose-specific lectin from Dioclea lasiophylla seeds, DlyL. The study aimed to evaluate in detail the interaction of DlyL with Xman and high-mannose N-glycans (MAN3, MAN5 and MAN9) by molecular dynamics (MD) and the resultant in vitro effect on vasorelaxation using rat aortic rings. In silico analysis of molecular docking was performed to obtain the initial coordinates of the DlyL complexes with the carbohydrates to apply as inputs in MD simulations. The MD trajectories demonstrated the stability of DlyL over time as well as different profiles of interaction with Xman and N-glycans. Furthermore, aortic rings assays demonstrated that the lectin could relax pre-contracted aortic rings with the participation of the carbohydrate recognition domain (CRD) and nitric oxide (NO) when endothelial tissue is preserved. These results confirm the ability of DlyL to interact with high-mannose N-glycans with its expanded CRD, supporting the hypothesis that DlyL vasorelaxant activity occurs primarily through its interaction with cell surface glycosylated receptors.Communicated by Ramaswamy H. Sarma.


Assuntos
Dioclea , Animais , Carboidratos/química , Dioclea/química , Dioclea/metabolismo , Lectinas , Manose/química , Simulação de Acoplamento Molecular , Lectinas de Plantas/análise , Lectinas de Plantas/química , Lectinas de Plantas/farmacologia , Polissacarídeos/farmacologia , Ratos , Sementes/química , Sementes/metabolismo , Vasodilatadores/análise , Vasodilatadores/química , Vasodilatadores/farmacologia
11.
Int J Biol Macromol ; 193(Pt B): 1562-1571, 2021 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-34740693

RESUMO

Lectins from plants of the Diocleinae subtribe often exhibit specificity towards mannose/glucose and derived sugars, with some plants also displaying a second lectin specific to lactose/GalNAc. Here, we present a novel lectin from Collaea speciosa, named CsL, that displays specificity for GlcNAc/glucose. The lectin was extracted from Collaea speciosa seeds and purified by a single chromatographic step on a Sephadex G-50 matrix. In solution, the lectin appears as a dimeric protein composed of 25 kDa monomers. The protein is stable at pH 7-8 and dependent on divalent cations. CsL maintained its agglutination activity after heating to 90 °C for 1 h. Glycan array studies revealed that CsL binds to N-glycans with terminal GlcNAc residues, chitobiose and chitotriose moieties. The partial amino acid sequence of the lectin is similar to that of some lactose-specific lectins from the same subtribe. In contrast to other ConA-like lectins, CsL is not toxic to Artemia. Because of its remarkably different properties and specificity, this lectin could be the first member of a new group inside the Diocleinae lectins.


Assuntos
Fabaceae/química , Lectinas de Plantas/química , Polissacarídeos/química , Polissacarídeos/metabolismo , Sementes/química , Sequência de Aminoácidos , Animais , Artemia/metabolismo , Glucose/metabolismo , Hemaglutinação , Manose/metabolismo
12.
Int J Biol Macromol ; 190: 543-553, 2021 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-34508719

RESUMO

Environmental factors, as well as genetic factors, contribute to the increase in prostate cancer cases (PCa), the second leading cause of cancer death in men. This fact calls for the development of more reliable, quick and low-cost early detection tests to distinguish between malignant and benign cases. Abnormal cell glycosylation pattern is a promising PCa marker for this purpose. Proteins, such as lectins can decode the information contained in the glycosylation patterns. Several studies have reported on applications of plant lectins as diagnostic tools for PCa considering the ability to differentiate it from benign cases. In addition, they can be used to detect, separate and differentiate the glycosylation patterns of cells or proteins present in serum, urine and semen. Herein, we present an overview of these studies, showing the lectins that map glycans differentially expressed in PCa, as well as benign hyperplasia (BPH). We further review their applications in biosensors, histochemical tests, immunoassays, chromatography, arrays and, finally, their therapeutic potential. This is the first study to review vegetable lectins applied specifically to PCa.


Assuntos
Lectinas/uso terapêutico , Hiperplasia Prostática/diagnóstico , Hiperplasia Prostática/terapia , Neoplasias da Próstata/diagnóstico , Neoplasias da Próstata/terapia , Animais , Glicosilação , Humanos , Lectinas/química , Masculino , Modelos Biológicos , Polissacarídeos/metabolismo
13.
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
14.
Basic Clin Pharmacol Toxicol ; 129(2): 130-138, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-33993648

RESUMO

Lectins are proteins that recognize specific carbohydrates, and the vasorelaxant effect of legume lectins has been previously reported, for example the Dioclea rostrata lectin (DRL). This study evaluated major pathways of DRL-induced relaxation in different artery segments and the possible molecular interactions involved. Rat thoracic aorta, coronary and mesenteric resistance arteries were tested "in vitro" with concentration-response curves to DRL (0.01-100 µg/mL). L-NAME, indomethacin and high KCl were used to evaluate nitric oxide, cyclooxygenase and hyperpolarization-dependent effects. DRL promoted relaxation of all vessels throughout different mechanisms. L-NAME blunted DRL-induced effects only in the aorta and mesenteric resistance artery. By the use of depolarizing KCl solution, vasodilation was reduced in all arteries, while incubation with indomethacin indicated a role of cyclooxygenase-derived factors for DRL effects in mesenteric and coronary arteries, but not in the aorta. Molecular docking results suggested interactions between DRL and heparan sulphate, CD31 and other glycans present on the membrane surface. These data indicate that the mechanisms involved in DRL-mediated vasodilation vary between conductance and resistance arteries of different origins, and these effects may be related to the capacity of DRL to bind a diversity of glycans, especially heparan sulphate, a proposed mechanoreceptor for nitric oxide synthase and cyclooxygenase activation.


Assuntos
Artérias/efeitos dos fármacos , Dioclea , Lectinas/metabolismo , Lectinas/farmacologia , Vasodilatação/efeitos dos fármacos , Vasodilatadores/farmacologia , Animais , Aorta Torácica/efeitos dos fármacos , Aorta Torácica/fisiologia , Artérias/fisiologia , Vasos Coronários/efeitos dos fármacos , Vasos Coronários/fisiologia , Masculino , Artérias Mesentéricas/efeitos dos fármacos , Artérias Mesentéricas/fisiologia , Simulação de Acoplamento Molecular , NG-Nitroarginina Metil Éster/farmacologia , Óxido Nítrico/metabolismo , Prostaglandina-Endoperóxido Sintases/metabolismo , Ratos , Ratos Wistar
15.
Int J Biol Macromol ; 181: 1104-1123, 2021 Jun 30.
Artigo em Inglês | MEDLINE | ID: mdl-33895178

RESUMO

Vicieae tribe, Leguminosae family (Fabaceae), has been extensively studied. In particular, the study of lectins. The purification, physicochemical and structural characterizations of the various purified lectins and the analysis of their relevant biological activities are ongoing. In this review, several works already published about Vicieae lectins are addressed. Initially, we presented the purification protocols and the physicochemical aspects, such as specificity for carbohydrates, optimal activity in the face of variations in temperature and pH, as well metals-dependence. Following, structural characterization studies are highlighted and, finally, various biological activities already reported are summarized. Studies on lectins in almost all genera (Lathyrus, Lens, Pisum and Vicia) are considered, with the exception of Vavilovia which studies of lectins have not yet been reported. Like other leguminous lectins, Vicieae lectins present heterogeneous profiles of agglutination profiles for erythrocytes and other cells of the immune system, and glycoproteins. Most Vicieae lectins consist of two subunits, α and ß, products of a single precursor protein derived from a single gene. The differences between the isoforms result from varying degrees of proteolytic processing. Along with the identification of these molecules and their characteristics, biological activities become very relevant and robust for both basic and applied research.


Assuntos
Carboidratos/química , Lectinas/química , Lectinas/isolamento & purificação , Vicia/química , Sequência de Aminoácidos/genética , Carboidratos/genética , Lectinas/genética , Lectinas/ultraestrutura
16.
Biochimie ; 180: 186-204, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-33171216

RESUMO

Glioblastoma multiforme is the most aggressive type of glioma, with limited treatment and poor prognosis. Despite some advances over the last decade, validation of novel and selective antiglioma agents remains a challenge in clinical pharmacology. Prior studies have shown that leguminous lectins may exert various biological effects, including antitumor properties. Accordingly, this study aimed to evaluate the mechanisms underlying the antiglioma activity of ConBr, a lectin extracted from the Canavalia brasiliensis seeds. ConBr at lower concentrations inhibited C6 glioma cell migration while higher levels promoted cell death dependent upon carbohydrate recognition domain (CRD) structure. ConBr increased p38MAPK and JNK and decreased ERK1/2 and Akt phosphorylation. Moreover, ConBr inhibited mTORC1 phosphorylation associated with accumulation of autophagic markers, such as acidic vacuoles and LC3 cleavage. Inhibition of early steps of autophagy with 3-methyl-adenine (3-MA) partially protected whereas the later autophagy inhibitor Chloroquine (CQ) had no protective effect upon ConBr cytotoxicity. ConBr also augmented caspase-3 activation without affecting mitochondrial function. Noteworthy, the caspase-8 inhibitor IETF-fmk attenuated ConBr induced autophagy and C6 glioma cell death. Finally, ConBr did not show cytotoxicity against primary astrocytes, suggesting a selective antiglioma activity. In summary, our results indicate that ConBr requires functional CRD lectin domain to exert antiglioma activity, and its cytotoxicity is associated with MAPKs and Akt pathways modulation and autophagy- and caspase-8- dependent cell death.


Assuntos
Antineoplásicos/farmacologia , Caspase 8/metabolismo , Ativação Enzimática/efeitos dos fármacos , Glioma/tratamento farmacológico , Sistema de Sinalização das MAP Quinases/efeitos dos fármacos , Lectinas de Plantas/farmacologia , Animais , Apoptose/efeitos dos fármacos , Astrócitos/efeitos dos fármacos , Autofagia/efeitos dos fármacos , Caspase 3/metabolismo , Morte Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Movimento Celular/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Glioma/metabolismo , Glioma/patologia , Humanos , Camundongos , Mitocôndrias/efeitos dos fármacos , Proteínas Quinases Ativadas por Mitógeno/metabolismo , Simulação de Acoplamento Molecular , Polissacarídeos/metabolismo , Domínios Proteicos/fisiologia , Estrutura Quaternária de Proteína/fisiologia , Estrutura Terciária de Proteína/fisiologia , Proteínas Proto-Oncogênicas c-akt/metabolismo , Ratos
17.
J Mol Recognit ; 33(11): e2870, 2020 11.
Artigo em Inglês | MEDLINE | ID: mdl-32648306

RESUMO

Lectins are a group of proteins of non-immune origin recognized for their ability to bind reversibly to carbohydrates. Researchers have been intrigued by oligosaccharides and glycoconjugates for their involvement as mediators of complex cellular events and then many biotechnological applications of lectins are based on glycocode decoding and their activities. Here, we report a structural and biological study of a ConA-like mannose/glucose-specific lectin from Canavalia bonariensis seeds, CaBo. More specifically, we evaluate the binding of CaBo with α-methyl-D-mannoside (MMA) and mannose-1,3-α-D-mannose (M13) and the resultant in vivo effects on a rat model of acute inflammation. A virtual screening was also carried out to cover a larger number of possible bindings of CaBo. In silico analysis demonstrated the stability of CaBo interaction with mannose-type ligands, and the lectin was able to induce acute inflammation in rats with the participation of the carbohydrate recognition domain (CRD) and histamine release. These results confirm the ability of CaBo to interact with hybrid and high-mannose N-glycans, supporting the hypothesis that CaBo's biological activity occurs primarily through its interaction with cell surface glycosylated receptors.


Assuntos
Carboidratos/química , Inflamação/tratamento farmacológico , Lectinas de Ligação a Manose/farmacologia , Lectinas de Plantas/farmacocinética , Animais , Sítios de Ligação , Histamina/farmacologia , Humanos , Inflamação/induzido quimicamente , Inflamação/patologia , Manose/química , Lectinas de Ligação a Manose/química , Manosídeos/química , Lectinas de Plantas/química , Lectinas de Plantas/farmacologia , Polissacarídeos/química , Ratos
18.
Int J Biol Macromol ; 162: 333-348, 2020 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-32574746

RESUMO

Lectins are a class of proteins with specific and reversible carbohydrate binding properties. Plant lectins constitute the group of these proteins most studied, placing emphasis on the legume family. The Caesalpinioideae subfamily is part of Leguminosae and second only to Papilionoideae with more published works on lectins. Classically, Caesalpinioideae is formed by 171 genera and 2250 species. It presents 13 genera with reports of lectins, featuring the Bauhinia genus with the greatest number of species having purified and characterized lectins. Comparing genera, the lectins in this subfamily do not have similar physicochemical or structural properties. Collectively, however, antibacterial, antiviral, and anticancer activities have been reported, as well as applications as biosensors and biomarkers. This review aims to summarize the available data on purified lectins from species of the Caesalpinioideae subfamily, demonstrating the characteristics of these molecules and the potential for their application in future studies of new lectins, as well as of application in several areas.


Assuntos
Antibacterianos/farmacologia , Antifúngicos/farmacologia , Antineoplásicos/farmacologia , Antivirais/farmacologia , Bauhinia/química , Lectinas de Plantas/química , Lectinas de Plantas/farmacologia , Sequência de Aminoácidos , Anti-Inflamatórios/farmacologia , Fabaceae/química , Metais/química , Conformação Molecular , Filogenia , Lectinas de Plantas/isolamento & purificação , Lectinas de Plantas/metabolismo , Domínios Proteicos
19.
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
20.
Int J Biol Macromol ; 156: 1-9, 2020 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-32275993

RESUMO

Lectins from Diocleinae subtribe species (family Leguminosae) are of special interest since they present a wide spectrum of biological activities, despite their high structural similarity. During their synthesis in plant cells, these proteins undergo post-translational processing resulting in the formation of three chains (α, ß, γ), which constitute the lectins' subunits. Furthermore, such wild-type proteins are presented as isolectins or with different combinations of these chains, which undermine their biotechnological potential. Thus, the present study aimed to produce a recombinant form of the lectin from Dioclea sclerocarpa seeds (DSL), exclusively constituted by α-chain. The recombinant DSL (rDSL) was successfully expressed in E. coli BL21 (DE3) and purified by affinity chromatography (Sephadex G-50), showing a final yield of 74 mg of protein per liter of culture medium and specificity for D-mannose, α-methyl-mannoside and melibiose, unlike the wild-type protein. rDSL presented an effective vasorelaxant effect in rat aortas up to 100% and also interacted with glioma cells C6 and U87. Our results demonstrated an efficient recombinant production of rDSL in a bacterial system that retained some biochemical properties of the wild-type protein, showing wider versatility in sugar specificities and better efficacy in its activity in the biological models evaluated in this work.


Assuntos
Dioclea/química , Lectinas de Plantas/química , Animais , Aorta/efeitos dos fármacos , Linhagem Celular Tumoral , Cromatografia de Afinidade , Escherichia coli/genética , Escherichia coli/metabolismo , Glioma/metabolismo , Hemaglutinação , Manose/química , Lectinas de Plantas/metabolismo , Estrutura Secundária de Proteína , Ratos , Proteínas Recombinantes/análise , Proteínas Recombinantes/biossíntese , Proteínas Recombinantes/isolamento & purificação , Proteínas Recombinantes/farmacologia , Sementes/química , Vasodilatadores/química
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