RESUMO
Lectins are a widely studied group of proteins capable of specific and reversible binding to carbohydrates. Undoubtedly, the best characterized are those extracted from plants of the Leguminosae family. Inside this group of proteins, those from the Diocleinae subtribe have attracted attention, in particular Concanavalin A (ConA), the best-studied lectin of the group. Diocleinae lectins, also called ConA-like lectins, present a high similarity of sequence and three-dimensional structure and are known to present inflammatory, vasoactive, antibiotic, immunomodulatory and antitumor activities, among others. This high similarity of lectins inside the ConA-like group makes it possible to use them to study structure/biological activity relationships by the variability of both carbohydrate specificity and biological activities results. It is in this context the following review aims to summarize the most recent data on the biochemical and structural properties, as well as biological activities, of ConA-like lectins and the use of these lectins as models to study structure/biological activity relationships.
Assuntos
Concanavalina A/química , Concanavalina A/farmacologia , Lectinas/química , Lectinas/farmacologia , Carboidratos/química , Fenômenos Químicos , Concanavalina A/genética , Concanavalina A/isolamento & purificação , Mediadores da Inflamação/química , Mediadores da Inflamação/metabolismo , Mediadores da Inflamação/farmacologia , Lectinas/genética , Lectinas/isolamento & purificação , Relação Estrutura-AtividadeRESUMO
Plant lectins have been studied owing to their structural properties and biological effects that include agglutinating activity, antidepressant-like effect and antitumor property. The results from this work showed the effects of the lectin extracted from the Dioclea violacea plant (DVL) on the C6 rat glioma cell line. DVL treatment was able to induce caspase-3 activation, apoptotic cell death and cellular membrane damage. Furthermore, DVL decreased mitochondrial membrane potential and increased the number of acidic vesicles and cleavage of LC3, indicating activation of autophagic processes. DVL also significantly inhibited cell migration. Compared to ConA, a well-studied lectin extracted from Canavalia ensiformes seeds, some effects of DVL were more potent, including decreasing C6 glioma cell viability and migration ability. Taken together, the results suggest that DVL can induce glioma cell death, autophagy and inhibition of cell migration, displaying potential anti-glioma activity.
Assuntos
Autofagia/efeitos dos fármacos , Dioclea/química , Expressão Gênica/efeitos dos fármacos , Neuroglia/efeitos dos fármacos , Lectinas de Plantas/farmacologia , Animais , Apoptose/efeitos dos fármacos , Apoptose/genética , Autofagia/genética , Canavalia/química , Caspase 3/genética , Caspase 3/metabolismo , Ciclo Celular/efeitos dos fármacos , Ciclo Celular/genética , Linhagem Celular Tumoral , Membrana Celular/efeitos dos fármacos , Membrana Celular/metabolismo , Membrana Celular/ultraestrutura , Movimento Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Concanavalina A/isolamento & purificação , Concanavalina A/farmacologia , L-Lactato Desidrogenase/metabolismo , Potencial da Membrana Mitocondrial/efeitos dos fármacos , Proteínas Associadas aos Microtúbulos/genética , Proteínas Associadas aos Microtúbulos/metabolismo , Mitocôndrias/efeitos dos fármacos , Mitocôndrias/metabolismo , Neuroglia/metabolismo , Neuroglia/patologia , Lectinas de Plantas/isolamento & purificação , RatosRESUMO
A PEG/citrate aqueous two-phase system was tested in the partition of commercial Concanavalin A (Con A) and subsequently applied to the extraction and purification of Con A from the crude extract of Canavalia ensiformis seeds. Con A was successfully extracted to the bottom phase of a system composed of 22% (w/w) PEG8000 and 12% (w/w) citrate at pH 6.0. The obtained purification factor was 11.5 without any loss in the hemagglutinating activity. The purity of extracted lectin was confirmed by SDS-PAGE analysis.
Assuntos
Canavalia/química , Fracionamento Químico/métodos , Ácido Cítrico/química , Concanavalina A/isolamento & purificação , Polietilenoglicóis/química , Análise de Variância , Concanavalina A/química , Eletroforese em Gel de Poliacrilamida , Concentração de Íons de Hidrogênio , Peso Molecular , Extratos Vegetais/química , Sementes/químicaRESUMO
This study reports on the antifungal activity of Dgui, a ConA-like lectin from Dioclea guianensis seeds. Dgui inhibited conidial germination but not mycelial growth of Colletotrichum gloeosporioides. The lectins ConA and ConM from Canavalia ensiformis and Canavalia maritima, respectively, share high levels of amino acid sequence similarity (>84%) with Dgui and have the same specificity toward glucose/mannose but had no effect on the fungus. Fluorescence microscopy showed that both Dgui and ConM bind to C. gloeosporioides ungerminated conidia. However, Dgui did not bind to C. gloeosporioides germinated conidia and germ tubes and was not inhibitory to mycelial growth. Because only Dgui inhibited germination of the fungus, C. gloeosporioides conidia might have surface-specific germination targets recognized by Dgui but not by its homologues, ConM and ConA. Therefore, Dgui is a candidate for biotechnological approaches for improving the resistance of various nutritionally and commercially important crops that are affected by C. gloeosporioides.
Assuntos
Antifúngicos/farmacologia , Colletotrichum/efeitos dos fármacos , Concanavalina A/farmacologia , Dioclea/metabolismo , Lectinas/farmacologia , Sequência de Aminoácidos , Antifúngicos/química , Antifúngicos/isolamento & purificação , Antifúngicos/metabolismo , Colletotrichum/crescimento & desenvolvimento , Concanavalina A/química , Concanavalina A/isolamento & purificação , Dioclea/química , Lectinas/química , Lectinas/economia , Lectinas/isolamento & purificação , Lectinas/metabolismo , Dados de Sequência Molecular , Alinhamento de SequênciaRESUMO
A simple and inexpensive procedure used magnetite and levan to synthesize a composite recovered by a magnetic field. Lectins from Canavalia ensiformis (Con A) and Cratylia mollis (Cramoll 1 and Cramoll 1, 4) did bind specifically to composite. The magnetic property of derivative favored washing out contaminating proteins and recovery of pure lectins with glucose elution. Cramoll 1 was purified by this affinity binding procedure in two steps instead of a previous three-step protocol with ammonium sulfate fractionation, affinity chromatography on Sephadex G-75, and ion exchange chromatography through a CM-cellulose column.
Assuntos
Óxido Ferroso-Férrico/química , Frutanos/química , Lectinas de Plantas/isolamento & purificação , Canavalia/química , Cromatografia Líquida , Concanavalina A/isolamento & purificação , Fabaceae/química , Frutanos/metabolismo , Testes de Inibição da Hemaglutinação , Ressonância Magnética Nuclear Biomolecular , Lectinas de Plantas/metabolismo , Zymomonas/químicaRESUMO
La concanavalina A es una lectina con múltiples aplicaciones en Medicina, Biología, Hematología, Inmunología y en Bioquímica. Esta lectina representa una valiosa herramienta para el estudio, aislammiento y purificación de diversas proteínas. La concanavalina A se purificó por un método de absorción específica en sephadex G-50, a partir de Canavalia ensiformis cosechada en Cuba. El rendimiento obtenido fue de 1,56 porciento. El producto mostró una actividad hemoaglutinadora de eritrocitos humanos menor que 3,91 µg, y una actividad turbidimétrica de 1,75 mg. Se realizaron estudios de enfoque isoeléctrico y electroforético al producto purificado, y por ambos métodos resultó ser idéntico al de la firma FLOW. La connavallina A se acopló a sefarosa 4B activada con bromuro de cianógeno, y la matriz de afinidad obtenida se utilizó en la purificación de una hormona glicoproteíca marcada radiactivamente con yodo-125 con resultados satisfactorios (AU)
Assuntos
Técnicas In Vitro , Concanavalina A/isolamento & purificação , Concanavalina A/análise , Concanavalina A/química , Fabaceae , CubaRESUMO
La concanavalina A es una lectina con múltiples aplicaciones en Medicina, Biología, Hematología, Inmunología y en Bioquímica. Esta lectina representa una valiosa herramienta para el estudio, aislammiento y purificación de diversas proteínas. La concanavalina A se purificó por un método de absorción específica en sephadex G-50, a partir de Canavalia ensiformis cosechada en Cuba. El rendimiento obtenido fue de 1,56 porciento. El producto mostró una actividad hemoaglutinadora de eritrocitos humanos menor que 3,91 µg, y una actividad turbidimétrica de 1,75 mg. Se realizaron estudios de enfoque isoeléctrico y electroforético al producto purificado, y por ambos métodos resultó ser idéntico al de la firma FLOW. La connavallina A se acopló a sefarosa 4B activada con bromuro de cianógeno, y la matriz de afinidad obtenida se utilizó en la purificación de una hormona glicoproteíca marcada radiactivamente con yodo-125 con resultados satisfactorios