Download MendeleyStructural Basis for the Interaction between Human Milk Oligosaccharides and the Bacterial Lectin Pa-Iil of Pseudomonas Aeruginosa.
Perret, S., Sabin, C., Dumon, C., Pokorna, M., Gautier, C., Galanina, O., Ilia, S., Bovin, N., Nicaise, M., Desmadril, M., Gilboa-Garber, N., Wimmerova, M., Mitchell, E.P., Imberty, A.(2005) Biochem J 389: 325
- PubMed: 15790314
- DOI: https://doi.org/10.1042/BJ20050079
- Primary Citation of Related Structures:
1W8F, 1W8H - PubMed Abstract:
One of the mechanisms contributing to the protection by breast-feeding of the newborn against enteric diseases is related to the ability of human milk oligosaccharides to prevent the attachment of pathogenic bacteria to the duodenual epithelium. Indeed, a variety of fucosylated oligosaccharides, specific to human milk, form part of the innate immune system. In the present study, we demonstrate the specific blocking of PA-IIL, a fucose-binding lectin of the human pathogen Pseudomonas aeruginosa, by milk oligosaccharides. Two fucosylated epitopes, Lewis a and 3-fucosyl-lactose (Lewis x glucose analogue) bind to the lectin with dissociation constants of 2.2x10(-7) M and 3.6x10(-7) M respectively. Thermodynamic studies indicate that these interactions are dominated by enthalpy. The entropy contribution is slightly favourable when binding to fucose and to the highest-affinity ligand, Lewis a. The high-resolution X-ray structures of two complexes of PA-IIL with milk oligosaccharides allow the precise determination of the conformation of a trisaccharide and a pentasaccharide. The different types of interaction between the oligosaccharides and the protein involve not only hydrogen bonding, but also calcium- and water-bridged contacts, allowing a rationalization of the thermodynamic data. This study provides important structural information about compounds that could be of general application in new therapeutic strategies against bacterial infections.
Organizational Affiliation:
Centre de Recherches sur les Macromolécules Végétales, CNRS, Université Joseph Fourier, BP53, 38041 Grenoble Cedex 09, France.
