Norovirus infection is the major cause of nonbacterial gastroenteritis in humans and has been the subject of numerous studies investigating the virus's biophysical properties and biochemical function with the aim of deriving novel and highly potent entry inhibitors to prevent infection. Recently, it has been shown that the protruding P domain dimer (P-dimer) of a GII.10 Norovirus strain exhibits two new binding sites for l-fucose in addition to the canonical binding sites. Thus, these sites provide a novel target for the design of multivalent fucose ligands as entry inhibitors of norovirus infections. In this current study, a first generation of multivalent fucose-functionalized glycomacromolecules was synthesized and applied as model structures to investigate the potential targeting of fucose binding sites in human norovirus P-dimer. Following previously established solid phase polymer synthesis, eight precision glycomacromolecules varying in number and position of fucose ligands along an oligo(amidoamine) backbone were obtained and then used in a series of binding studies applying native MS, NMR, and X-ray crystallography. We observed only one fucose per glycomacromolecule binding to one P-dimer resulting in similar binding affinities for all fucose-functionalized glycomacromolecules, which based on our current findings we attribute to the overall size of macromolecular ligands and possibly to steric hindrance.

Precision glycomacromolecules have provent ob e important tools for the investigation of multivalent carbohydrate-lectin interactions by presenting multiple glycan epitopes on ah ighly-defined synthetic scaffold. Herein, we present an ew strategy for the versatile assembly of heteromultivalentg lycomacromolecules that contain differentc arbohydrate motifs in proximity within the side chains. An ew building block suitable fort he solid-phase polymers ynthesis of precision glycomacromolecules was developed with a branching point in the side chain that bears af ree alkyne and aT IPS-protected alkyne moiety,w hich enables the subsequent attachment of different carbohydrate motifs by onresin copper-mediated azide-alkyne cycloaddition reactions. Applying this synthetic strategy,h eteromultivalent glycooligomers presenting fragments of histo-blood group antigens and human milk oligosaccharides were synthesized and tested for their binding behavior towards bacterial lectin LecB.[a] K.Scheme1.Introduction of an ew building block during solid-phase polymer synthesis provides for the asymmetrical conjugation of ligands by coupling ac arbohydrate ligand to the free alkyne by using CuAAC( e.g.,fucose in red) followed by deprotectiono ft he second alkyne moiety andcoupling of as econd carbohydrate ligand (e.g.,GalNAcinb lue).Scheme2.Synthetic route for new building block iso-DTDS 7,w hich combines precursor 1 [23] and key intermediate 2. [17,20] Chem.E ur.

The opportunistic bacterium Pseudomonas aeruginosa, often exhibiting multiresistance against conventional antibiotics, expresses the lectin LecB that is suspected to be an important factor during biofilm formation via interactions with cell‐surface presented carbohydrate ligands such as the blood group antigens. Therefore, carbohydrate‐based ligands interfering with LecB binding have the potential to lead to new anti‐biofilm and anti‐adhesion therapies. This study explores in vitro binding potencies of glycomimetic ligands containing up to six α‐l‐fucose ligands on a monodisperse, sequence‐controlled oligoamide scaffold interacting with LecB. Surface plasmon resonance (SPR) and a modified enzyme‐linked lectin assay (mELLA) revealed an increasing affinity to LecB with increasing fucose valency. Furthermore, fucosylated glycooligomers were shown to inhibit the formation of P. aeruginosa biofilm up to 20%. Overall these results show the potential of fucosylated oligoamides to be further developed as inhibitors of LecB binding and biofilm formation.