| Congresso Brasileiro de Microbiologia 2023 | Resumo: 218-1 | ||||
Resumo:Lectins are defined as a class of proteins - or glycoproteins - that reversibly recognize carbohydrates or glycoconjugates with high affinity and specificity. The lectins of the Diocleinae subtribe show a high degree of homology in amino acid sequence, with highly conserved regions, and similarity in three-dimensional structure. Regarding biological activities, studies have reported several applications of lectins from the Diocleinae subtribe, included antibacterial activity. In this study, a lectin from seeds of Dioclea bicolor was purified and its antimicrobial activity was evaluated. The protein was purified by affinity purification. Electrophoresis analysis presents that DBL have three bands with molecular mass of 29 kDa (α chain); 20 and 14 kDa (β and γ chains, respectively). The DBL native form, determined by gel filtration chromatography, present a molecular mass at approximately 100 kDa, suggested that the lectin is a tetramer. The hemagglutination caused by DBL was inhibited by several glucosides and mannosides, and also by ampicillin and tetracycline. The complete amino acid sequences of DBL was elucidated by MS/MS and its 3D structure model generated showed a monomer characteristic from legume lectins, consisting of a β-sandwich. Molecular docking calculations interactions between DBL and α-D-glucose, N-acetyl-D-glucosamine, α-D-mannose, α-methyl-D-mannoside, ampicillin and tetracycline. The lectin showed antimicrobial activity at 125 μg/mL against Staphylococcus aureus, Staphylococcus epidermidis, Escherichia coli and Pseudomonas aeruginosa strains. In addition, DBL showed synergistic effect in combination with ampicillin against S. aureus and S. epidermidis; and in combination tetracycline against S. aureus, S. epidermidis, E. coli and P. aeruginosa. The results suggesting DBL is a protein with antimicrobial activity and presenting increase the activity of antibiotics. Palavras-chave: Plant lectin, Dioclea bicolor, ConA-like, antimicrobial activity, synergistic effect Agência de fomento:Fundação de Amparo à Pesquisa do Estado de Minas Gerais | |||||