Screening of a Library of Oligosaccharides Targeting Lectin LecB of and Synthesis of High Affinity Oligoglycoclusters.

The Gram negative bacterium (PA) is an opportunistic bacterium that causes severe and chronic infection of immune-depressed patients. It has the ability to form a biofilm that gives a selective advantage to the bacteria with respect to antibiotherapy and host defenses. Herein, we have focused on the tetrameric soluble lectin which is involved in bacterium adherence to host cells, biofilm formation, and cytotoxicity.

Synthesis of α-galactosyl epitopes by metabolically engineered Escherichia coli.

The α-Gal epitope is a carbohydrate structure, Galα-3Galβ-4GlcNAc-R, expressed on glycoconjuguates in many mammals, but not in humans. Species that do not express this epitope have present in their serum large amounts of natural anti-Gal antibodies, which contribute to organ hyperacute rejection during xenotransplantation. We first describe the efficient conversion of lactose into isoglobotriaose (Galα-3Galβ-4Glc) using high cell density cultures of a genetically engineered Escherichia coli strain expressing the bovine gene for α-1,3-galactosyltransferase.