In this study,the interaction of exopolysaccharides from Leuconostoc mesenteroides P35(EPS-LM)with Escherichia coli heat-labile enterotoxin B-pentamer(LTB)was investigated at different concentrations and temperatures ...In this study,the interaction of exopolysaccharides from Leuconostoc mesenteroides P35(EPS-LM)with Escherichia coli heat-labile enterotoxin B-pentamer(LTB)was investigated at different concentrations and temperatures by using surface plasmon resonance(SPR)and molecular docking approaches.FT-IR spectral analysis together with HPTLC analysis revealing that glucose is the only constitutive monosaccharide of EPS-LM suggests that its structure is composed of dextran withα-D(1→6)glycosidic linkages.SPR analysis revealed the high affinity of EPS-LM for immobilized LTB toxin(KA=(2.05±0.04)×106 mol.L−1 at 37°C).The binding process was spontaneous(ΔG<0),endothermic(ΔH>0),and entropy-driven(ΔS>0)with an increase of KA with temperature.This suggests that EPS-LM-LTB interaction is dominated by hydrophobic forces.The binding affinity of EPS-LM to LTB had negligible dependence on enthalpy(ΔH=0.084 kJ mol−1).Further,molecular docking results suggested the presence of some binding sites of EPS-LM on the LTB through hydrophobic forces(Lys,Asp,Arg,Glu)and also hydrogen bonding(Glu)in the hydrophobic core of LTB.Besides autodock studies,Schiffer-Edmundson helical wheel diagrams of LTB inα-helix domain suggested that LTB hydrophobic core is a highly effective region,which was able to form favorable non-polar interactions of the protein's binding surface(with amino acids residues such as Tyr,Leu,Ile)with EPS-LM.This study provided thus further insights into the interactions between EPS-LM and LTB,suggesting that EPS produced by some LAB,such as EPS produced by Ln.mesenteroides P35 strain are good candidates to inhibit E.coli toxin activity.展开更多
基金the Minist`ere des Affaires Etrang`eres(France)and the Ministry of Research,Science and Technology(Iran)for financing double PhD scholarship joint-supervision program between France and Iran for Mojtaba AZARI-ANPARThe authors are indebted to Conseil D´epartemental de l’Ain and Bourg en Bresse Agglom´eration for the financial support of BioDyMIA research unit activities.
文摘In this study,the interaction of exopolysaccharides from Leuconostoc mesenteroides P35(EPS-LM)with Escherichia coli heat-labile enterotoxin B-pentamer(LTB)was investigated at different concentrations and temperatures by using surface plasmon resonance(SPR)and molecular docking approaches.FT-IR spectral analysis together with HPTLC analysis revealing that glucose is the only constitutive monosaccharide of EPS-LM suggests that its structure is composed of dextran withα-D(1→6)glycosidic linkages.SPR analysis revealed the high affinity of EPS-LM for immobilized LTB toxin(KA=(2.05±0.04)×106 mol.L−1 at 37°C).The binding process was spontaneous(ΔG<0),endothermic(ΔH>0),and entropy-driven(ΔS>0)with an increase of KA with temperature.This suggests that EPS-LM-LTB interaction is dominated by hydrophobic forces.The binding affinity of EPS-LM to LTB had negligible dependence on enthalpy(ΔH=0.084 kJ mol−1).Further,molecular docking results suggested the presence of some binding sites of EPS-LM on the LTB through hydrophobic forces(Lys,Asp,Arg,Glu)and also hydrogen bonding(Glu)in the hydrophobic core of LTB.Besides autodock studies,Schiffer-Edmundson helical wheel diagrams of LTB inα-helix domain suggested that LTB hydrophobic core is a highly effective region,which was able to form favorable non-polar interactions of the protein's binding surface(with amino acids residues such as Tyr,Leu,Ile)with EPS-LM.This study provided thus further insights into the interactions between EPS-LM and LTB,suggesting that EPS produced by some LAB,such as EPS produced by Ln.mesenteroides P35 strain are good candidates to inhibit E.coli toxin activity.
