RESUMO
The Arachis genus belongs to the Dalbergieae tribe, a group of plants that show promising potential novel lectins. Three lectins of the well-known Arachis hypogaea have already been purified, while lectins from related species are still unknown. Genomes of two closely related species, Arachis duranensis and Arachis ipaensis, were recently sequenced. Therefore, this study aimed to establish the three-dimensional structure of Arachis duranensis lectin (ADL) and Arachis ipaensis lectin (AIL) by homology modeling, test their activity against mannosides, and perform molecular dynamics (MD) simulations on these two proteins, both unligated and interacting with mannose or α-methyl-D-mannoside. The fold obtained for the molecular models agrees with data obtained from previous leguminous lectins, showing a conserved jelly roll motif. Docking scores indicate that these lectins have different theoretical binding energy with monosaccharides, disaccharides, and high-mannose glycans. MD simulations revealed that these proteins are α-methyl-D-mannoside-specific, having less stable interactions with mannose. This study thus serves as a guide for further research on lectins of the Arachis genus.
RESUMO
Lectins represent a class of proteins or glycoproteins capable of reversibly binding to carbohydrates. Seed lectins from the Dalbergieae tribe (Leguminosae) have structural variability, carbohydrate specificity, and biological effects, such as inflammation, vasorelaxation and cancer antigen binding. To comprehensively address these factors, the present work aimed to establish and characterize the three-dimensional structure of Centrolobium microchaete lectin (CML) by homology modeling, investigate protein-carbohydrate interactions and evaluate its inflammatory effect on mice. Molecular docking was performed to analyze interactions of the lectin with monosaccharides, disaccharides and N-glycans. Two dimannosides, methyl mannose-1,3-α-D-mannose (MDM) and mannose-1,3-α-D-mannose (M13), were used in molecular dynamics (MD) simulations to study the behavior of the carbohydrate-recognition domain (CRD) over time. Results showed an expanded domain within which hydrophobic interactions with the methyl group in the MDM molecule were established, thus revealing novel interactions for mannose-specific Dalbergieae lectins. To examine its biological activities, CML was purified in a single step by affinity chromatography on Sepharose-mannose matrix. The lectin demonstrated inflammatory response in the paw edema model and stimulated leukocyte migration to the animal peritoneal cavities, an effect elicited by CRD. For the first time, this work reports the molecular dynamics of a lectin from the Dalbergieae tribe.
Assuntos
Fabaceae/química , Simulação de Acoplamento Molecular , Simulação de Dinâmica Molecular , Estrutura Molecular , Lectinas de Plantas/química , Sementes/química , Animais , Anti-Inflamatórios não Esteroides/química , Anti-Inflamatórios não Esteroides/isolamento & purificação , Anti-Inflamatórios não Esteroides/farmacologia , Sítios de Ligação , Modelos Animais de Doenças , Edema/tratamento farmacológico , Edema/etiologia , Edema/patologia , Metais/química , Camundongos , Lectinas de Plantas/isolamento & purificação , Lectinas de Plantas/farmacologia , Ligação Proteica , Domínios e Motivos de Interação entre Proteínas , Relação Estrutura-AtividadeAssuntos
Dioclea/química , Lectinas de Ligação a Manose/química , Lectinas de Plantas/química , Sementes/química , Animais , Apoptose/efeitos dos fármacos , Sítios de Ligação , Linhagem Celular Tumoral , Movimento Celular/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Cristalização , Glioma , Lectinas de Ligação a Manose/isolamento & purificação , Lectinas de Ligação a Manose/farmacologia , Simulação de Acoplamento Molecular , Lectinas de Plantas/isolamento & purificação , Lectinas de Plantas/farmacologia , Ligação Proteica , Conformação Proteica , RatosRESUMO
The lectin from Platypodium elegans seeds (PELa) was purified by affinity chromatography in a mannose-agarose column. The lectin agglutinated rabbit erythrocytes and the agglutinating effect was inhibited by previous incubation with the glycoprotein fetuin, along with N-acetyl-d-glucosamine, D-mannose and its derivatives. The lectin maintained complete activity in temperatures ranging from 40 to 60°C and pH values ranging from 9 to 10. As a glycoprotein, PELa has a carbohydrate content of 2.2%, and its activity requires divalent cations such as Ca2+ and Mn2+. Based on SDS-PAGE, PELa displays a profile similar to that of other Dalbergieae lectins with the main chain of molecular mass around 30kDa and two subunits of 19kDa and 10 kDa each. Two-dimensional (2D) electrophoresis revealed the presence of isoforms with different isoelectric points, and high-performance size exclusion chromatography (HPSEC) was performed to confirm the purity of the sample. The lectin was immobilized in CNBr-activated Sepharose 4B and successfully captured fetuin in solution, demonstrating that this lectin remains active and capable of binding carbohydrates. PELa showed effects different from those of its recombinant form in both pro- and anti-inflammatory tests.