• Development of a competitive binding assay for the Burkholderia cenocepacia lectin BC2L-A and structure activity relationship of natural and synthetic inhibitors

      Beshr, Ghamdan; Sommer, Roman; Hauck, Dirk; Siebert, David Chan Bodin; Hofmann, Anna; Imberty, Anne; Titz, Alexander (2016)
    • Synthesis of mannoheptose derivatives and their evaluation as inhibitors of the lectin LecB from the opportunistic pathogen Pseudomonas aeruginosa.

      Hofmann, Anna; Sommer, Roman; Hauck, Dirk; Stifel, Julia; Göttker-Schnetmann, Inigo; Titz, Alexander; hemical Biology of Carbohydrates, Helmholtz Institute for Pharmaceutical Research Saarland (HIPS), D-66123 Saarbrücken, Germany. (2015-05-05)
      Biofilm formation and chronic infections with Pseudomonas aeruginosa depend on lectins produced by the bacterium. The bacterial C-type lectin LecB binds to the two monosaccharides l-fucose and d-mannose and conjugates thereof. Previously, d-mannose derivatives with amide and sulfonamide substituents at C6 were reported as potent inhibitors of the bacterial lectin LecB and LecB-mediated bacterial surface adhesion. Because d-mannose establishes a hydrogen bond via its 6-OH group with Ser23 of LecB in the crystal structure and may be beneficial for binding affinity, we extended d-mannose and synthesized mannoheptoses bearing the free 6-OH group as well as amido and sulfonamido-substituents at C7. Two series of diastereomeric mannoheptoses were synthesized and the stereochemistry was determined by X-ray crystallography. The potency of the mannoheptoses as LecB inhibitors was assessed in a competitive binding assay. The data reveal a diastereoselectivity of LecB for (6S)-mannoheptose derivatives with increased activity over methyl α-d-mannoside.