title: Burkholderia cenocepacia lectin A binding to heptoses from the bacterial lipopolysaccharide.
abstract: Bacteria from the Burkholderia cepacia complex (Bcc) cause highly contagious pneumonia among cystic fibrosis (CF) patients. Among them, Burkholderia cenocepacia is one of the most dangerous in the Bcc and is the most frequent cause of morbidity and mortality in CF patients. Indeed, it is responsible of "cepacia syndrome", a deadly exacerbation of infection, that is the main cause of poor outcomes in lung transplantation. Burkholderia cenocepacia produces several soluble lectins with specificity for fucosylated and mannosylated glycoconjugates. These lectins are present on the bacterial cell surface and it has been proposed that they bind to lipopolysaccharide epitopes. In this work, we report on the interaction of one B. cenocepacia lectin, BC2L-A, with heptose and other manno configured sugar residues. Saturation transfer difference NMR spectroscopy studies of BC2L-A with different mono- and disaccharides demonstrated the requirement of manno configuration with the hydroxyl or glycol group at C6 for the binding process. The crystal structure of BC2L-A complexed with the methyl-heptoside confirmed the location of the carbohydrate ring in the binding site and elucidated the orientation of the glycol tail, in agreement with NMR data. Titration calorimetry performed on monosaccharides, heptose disaccharides and bacterial heptose-containing oligosaccharides and polysaccharides confirmed that bacterial cell wall contains carbohydrate epitopes that can bind to BC2L-A. Additionally, the specific binding of fluorescent BC2L-A lectin on B. cenocepacia bacterial surface was demonstrated by microscopy.
authors: Dipartimento di Scienze Chimiche, Università di Napoli "Federico II", Italy.
authors: Roberta
authors: R
authors: Marchetti
authors: Lenka
authors: L
authors: Malinovska
authors: Emilie
authors: E
authors: Lameignère
authors: Lenka
authors: L
authors: Adamova
authors: Cristina
authors: C
authors: de Castro
authors: Gianluca
authors: G
authors: Cioci
authors: Christian
authors: C
authors: Stanetty
authors: Paul
authors: P
authors: Kosma
authors: Antonio
authors: A
authors: Molinaro
authors: Michaela
authors: M
authors: Wimmerova
authors: Anne
authors: A
authors: Imberty
authors: Alba
authors: A
authors: Silipo
mesh_terms: D001665:Binding Sites; D057508:Burkholderia cenocepacia / Q000737:chemistry* / Q000166:cytology; D002236:Carbohydrate Conformation; D006539:Heptoses / Q000737:chemistry*; D037102:Lectins / Q000737:chemistry*; D008070:Lipopolysaccharides / Q000737:chemistry*; D008958:Models, Molecular
chemical_list: D006539:Heptoses; D037102:Lectins; D008070:Lipopolysaccharides