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 , ApoptoseRESUMO
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/análiseRESUMO
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/metabolismoRESUMO
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 XRESUMO
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-AtividadeRESUMO
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/químicaRESUMO
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/químicaRESUMO
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 TumoraisRESUMO
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/farmacologiaRESUMO
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/ultraestruturaRESUMO
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/metabolismoRESUMO
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 , RatosRESUMO
Lectins are proteins capable of specific and reversible binding to mono- and/or oligosaccharides, and within this group, Legume lectins are the most studied. However, most of these studies focus on the Papilionoideae subfamily, with Caesalpinioideae and Mimosoideae lectins being significantly less explored in the literature. The Mimosoideae subfamily consists of at least 79 genera and 3275 species, but, to date, only about 14 lectins have been purified, a fact which shows the lack of studies for this group. Based on their purification protocols, as well as physicochemical and structural properties, Mimosoideae lectins are very heterogeneous. Despite the few studies, a wide variety of biological activities have been tested, including, for example, inflammatory, anticancer, antibacterial, and antifungal. In this context, the present review aims to summarize the available data regarding the purification, physicochemical and structural properties, as well as biological activities, of lectins extracted from plants of the Mimosoideae subfamily in order to bring more insight to researchers interested in further exploring the potential of these molecules.
Assuntos
Fabaceae/química , Lectinas de Plantas/química , Lectinas de Plantas/farmacologia , Fenômenos QuímicosRESUMO
Lectins are (glyco)proteins capable of reversibly binding to specific carbohydrates, thus having various functions and applications. Plant lectins are the best studied, and the Leguminoseae family is highlighted in a number of published works, especially species of the Papilionoideae subfamily. Dalbergieae is one of the tribes in this subfamily comprising 49 genera and over 1300 species. From this tribe, about 26 lectins were studied, among which we can highlight the Arachis hypogaea lectin, widely used in cancer studies. Dalbergieae lectins demonstrate various carbohydrate specificities and biological activities including anti-inflammatory, vasorelaxant, nociceptive, antibacterial, antiviral among others. Structurally, these lectins are quite similar in their three-dimensional folding but present significant differences in oligomerization patterns and in the conservation of carbohydrate-recognition domain. Despite the existence of structural data from some lectins, only sparse literature has reported on this tribe's diversity, not to mention the range of biological effects, determined through specific assays. Therefore, this work will review the most important studies on Dalbergieae lectins and their potential biomedical applications.
Assuntos
Fabaceae/química , Lectinas de Plantas/química , Lectinas de Plantas/uso terapêutico , Sítios de Ligação , Carboidratos/química , Dobramento de Proteína , Homologia Estrutural de ProteínaRESUMO
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 ProteicosRESUMO
The Tn antigen is an epitope containing N-acetyl-D-galactosamine present in the extracellular matrix of some carcinoma cells in humans, and it is often used as a biomarker. Lectins are proteins capable of binding to carbohydrates and can be used as a molecular tool to recognize antigens and to differentiate cancer cells from normal cells. In this context, the present work aimed to characterize the interaction of Vatairea guianensis seed lectin with N-acetyl-D-galactosamine and the Tn antigen by molecular dynamics and molecular mechanics/Poisson-Boltzmann solvent-accessible surface area analysis. This study revealed new interacting residues not previously identified in static analysis of the three-dimensional structures of Vatairea lectins, as well as the configuration taken by the carbohydrate recognition domain, as it interacts with each ligand. During the molecular dynamics simulations, Vatairea guianensis lectin was able to bind stably to Tn antigen, which, as seen previously for other lectins, enables its use in cancer research, diagnosis, and therapy. This work further demonstrates the efficiency of bioinformatics in lectinology.
Assuntos
Fabaceae/química , Simulação de Dinâmica Molecular , Lectinas de Plantas/química , Humanos , Neoplasias , Domínios ProteicosRESUMO
Lectins are proteins that have as one of their main characteristics recognizing and reversibly binding to carbohydrates. In this work, it was possible to purify and characterize a lectin from Parkia panurensis (Leguminosae family; Mimosoideae subfamily) seeds by a combination of the techniques: protein precipitation, along with affinity and then ion exchange chromatography using the Sepharose-mannose and diethylaminoethyl matrices, respectively. The pure lectin, called PpaL, has affinity by D-mannose, D-glucose and derivatives. PpaL was stable over a wide range of temperature and pH, and it showed an SDS-PAGE profile of only one protein band with apparent mass of 45 kDa, subsequently confirmed by mass spectrometry, and presented a molecular mass of 50,566 ± 1 Da. PAGE analysis and molecular exclusion chromatography demonstrated that PpaL is presented as a dimer in solution. Partial sequencing of the primary structure resulted in a total of 334 amino acid residues with approximately 97% similarity to Parkia biglobosa and Parkia platycephala seed lectins. PpaL was shown to be toxic against Artemia nauplii and had an LC50 of 20 µg/mL. The effects of biological activities presented by these proteins make them important biotechnological tools, demonstrating the importance of bioprospection of new lectins.
Assuntos
Fabaceae/química , Lectinas de Plantas/química , Sementes/química , Animais , Artemia/química , Cromatografia de Afinidade/métodos , Glucose/química , Concentração de Íons de Hidrogênio , Manose/química , TemperaturaRESUMO
Lectins are defined as proteins or glycoproteins capable of specific and reversible binding to carbohydrates. Inside this group of proteins, the most well-studied lectins belong to the Leguminosae family, and inside this family, the Diocleinae subtribe includes the most characterized lectin Concanavalin A (ConA), as well as ConBr, the lectin from Canavalia brasiliensis, the subject of this review. Since 1979, several studies have been published in the literature regarding this lectin, from its isolation and characterization to its several biological activities. This year, 2019, will mark 40 years since researchers have begun to study ConBr and 100 years since the discovery of ConA, making 2019 a momentous year for lectinology. Owing to the abundance of studies involving ConBr, this review will focus on ConBr's purification, physicochemical properties, functional and structural analyses, biological activities and biotechnological applications. This will give researchers a broad glimpse into the potential of this lectin, as well as it characteristics, as we look ahead to its expanding applications in glycomics and biotechnology.
Assuntos
Canavalia/química , Lectinas de Plantas/isolamento & purificação , Sementes/química , Animais , Apoptose/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Concanavalina A/metabolismo , Humanos , Concentração de Íons de Hidrogênio , Modelos Moleculares , Extratos Vegetais/isolamento & purificação , Extratos Vegetais/farmacologia , Lectinas de Plantas/farmacologia , Ligação Proteica , Conformação ProteicaRESUMO
Lectins are proteins that can bind specifically and reversibly to carbohydrates. This capacity gives lectins multiple biological roles and biotechnological applications. Although lectins can be found in all organisms, plant lectins, especially legume lectins, are undoubtedly the most thoroughly studied. Among legume lectins, the lectin from Canavalia ensiformis (ConA) and Canavalia brasiliensis (ConBr), both from Diocleinae subtribe, are two of the most well-known lectins. It has been 100â¯years since the first report of ConA and 40â¯years since the first report of ConBr, making 2019 an important year for lectinology. Structural data of these lectins in combination with biological activity tests clearly indicate that even a small shift in amino acid sequence can affect the tertiary and quaternary structures, consequently affecting the biological activity of these proteins. It is in this context that the present paper aims to review the structural data of ConA and ConBr, focusing on the primary structure, crystallography, tertiary and quaternary structures of these lectins, as well as their binding sites. This paper also expands the structural data by employing molecular dynamics to evaluate carbohydrate-binding properties and structural stability. It is anticipated that these data will increase knowledge about the structure-function relationships of these proteins.