Title
Isolation, biochemical characterization and antibiofilm effect of a lectin from the marine sponge Aplysina lactuca
Author
Rômulo Farias Carneiro, Paulo Henrique Pinheiro de Lima Jr, Renata Pinheiro Chaves, Rafael Pereira, Anna Luísa Pereira, Mayron Alves de Vasconcelos, Ulisses Pinheiro, Edson Holanda Teixeira, Celso Shiniti Nagano, Alexandre Holanda Sampaio
Year
2017
Journal
International Journal of Biological Macromolecules
Abstract
A new lectin was isolated from the marine sponge Aplysina lactuca (ALL) by combining ammonium sulfate precipitation and affinity chromatography on guar gum matrix. ALL showed affinity for the disaccharides α-lactose, β-lactose and lactulose (Ka = 12.5, 31.9 and 145.5 M−1, respectively), as well as the glycoprotein porcine stomach mucin. Its hemagglutinating activity was stable in neutral acid pH values and temperatures below 60 °C. ALL is a dimeric protein formed by two covalently linked polypeptide chains. The average molecular mass, as determined by Electrospray Ionization Mass Spectrometry (ESI-MS), was 31,810 ±2 Da. ESI-MS data also indicated the presence of three cysteines involved in one intrachain and one interchain disulfide bond. The partial amino acid sequence of ALL was determined by tandem mass spectrometry. Eight tryptic peptides presented similarity with lectin I isolated from Axinella polypoides. Its secondary structure is predominantly β-sheet, as indicated by circular dichroism (CD) spectroscopy. ALL agglutinated gram-positive and gram-negative bacterial cells, and it was able to significantly reduce the biomass of the bacterial biofilm tested at dose- dependent effect.
Instrument
J-815
Keywords
Circular dichroism, Secondary structure, Thermal stability, Ligand binding, Biochemistry