High-Affinity Lectin Ligands Enable the Detection of Pathogenic Biofilms: Implications for Diagnostics and Therapy.

is a critical priority pathogen and causes life-threatening acute and biofilm-associated chronic infections. The choice of suitable treatment for complicated infections requires lengthy culturing for species identification from swabs or an invasive biopsy. To date, no fast, pathogen-specific diagnostic tools for infections are available.

Microwave-Assisted Synthesis of β--Aryl Glycoamphiphiles with Diverse Supramolecular Assemblies and Lectin Accessibility.

Glycoamphiphiles have attracted considerable interest in a broad range of application fields owing to their solution and bulk-state self-assembly abilities. Despite their importance, the straightforward synthesis of glycoamphiphiles consisting of a hydrophilic carbohydrate linked to a hydrophobic aglycone remains one of the major challenges in glycosciences. Here, a rapid, simple, and efficient synthetic access to chemically stable glycoamphiphiles at physiological pH, namely, -(β-d-glycosyl)-2-alkylbenzamide, is reported.

Photoswitchable glycoligands targeting LecA.

Biofilm formation is one of main causes of bacterial antimicrobial resistance infections. It is known that the soluble lectins LecA and LecB, produced by , play a key role in biofilm formation and lung infection. Bacterial lectins are therefore attractive targets for the development of new antibiotic-sparing anti-infective drugs.

HumanLectome, an update of UniLectin for the annotation and prediction of human lectins.

The UniLectin portal (https://unilectin.unige.ch/) was designed in 2019 with the goal of centralising curated and predicted data on carbohydrate-binding proteins known as lectins.

A Shiga Toxin B-Subunit-Based Lectibody Boosts T Cell Cytotoxicity towards Gb3-Positive Cancer Cells.

Aberrant glycosylation plays a crucial role in tumour progression and invasiveness. Tumour-associated carbohydrate antigens (TACAs) represent a valuable set of targets for immunotherapeutic approaches. The poor immunogenicity of glycan structures, however, requires a more effective and well-directed way of targeting TACAs on the surface of cancer cells than antibodies.

Spatiotemporal Landscape for the Sophisticated Transformation of Protein Assemblies Defined by Multiple Supramolecular Interactions.

Precise protein assemblies not only constitute a series of living machineries but also provide an advanced class of biomaterials. Previously, we developed the inducing ligand strategy to generate various fixed protein assemblies, without the formation of noncovalent interactions between proteins. Here, we demonstrated that controlling the symmetry and number of supramolecular interactions introduced on protein surfaces could direct the formation of unspecific interactions between proteins and induce various nanoscale assemblies, including coiling nanowires, nanotubes, and nanosheets, without manipulation of the protein's native surfaces.

BiotechLec: an interactive guide of commercial lectins for glycobiology and biomedical research applications.

For decades, lectins have been used as probes in glycobiology and this usage has gradually spread to other domains of Life Science. Nowadays, researchers investigate glycan recognition with lectins in diverse biotechnology and clinical applications, addressing key questions regarding binding specificity. The latter is documented in scattered and heterogeneous sources, and this situation calls for a centralized and easy-access reference.

Cell-free expression and characterization of multivalent rhamnose-binding lectins using bio-layer interferometry.

Lectins are important biological tools for binding glycans, but recombinant protein expression poses challenges for some lectin classes, limiting the pace of discovery and characterization. To discover and engineer lectins with new functions, workflows amenable to rapid expression and subsequent characterization are needed. Here, we present bacterial cell-free expression as a means for efficient, small-scale expression of multivalent, disulfide bond-rich, rhamnose-binding lectins.

Tuning specificity and topology of lectins through synthetic biology.

Lectins are non-immunoglobulin and non-catalytic glycan binding proteins that are able to decipher the structure and function of complex glycans. They are widely used as biomarkers for following alteration of glycosylation state in many diseases and have application in therapeutics. Controlling and extending lectin specificity and topology is the key for obtaining better tools.

Increasing the Hydrophilicity of Cyclic Ketene Acetals Improves the Hydrolytic Degradation of Vinyl Copolymers and the Interaction of Glycopolymer Nanoparticles with Lectins.

Radical ring-opening polymerization (rROP) of cyclic ketene acetals (CKAs) with traditional vinyl monomers allows the synthesis of degradable vinyl copolymers. However, since the most commonly used CKAs are hydrophobic, most degradable vinyl copolymers reported so far degrade very slowly by hydrolysis under physiological conditions (phosphate-buffered saline, pH 7.4, 37 °C), which can be detrimental for biomedical applications.

Targeting undruggable carbohydrate recognition sites through focused fragment library design.

Carbohydrate-protein interactions are key for cell-cell and host-pathogen recognition and thus, emerged as viable therapeutic targets. However, their hydrophilic nature poses major limitations to the conventional development of drug-like inhibitors. To address this shortcoming, four fragment libraries were screened to identify metal-binding pharmacophores (MBPs) as novel scaffolds for inhibition of Ca-dependent carbohydrate-protein interactions.

Discovery of potent 1,1-diarylthiogalactoside glycomimetic inhibitors of Pseudomonas aeruginosa LecA with antibiofilm properties.

In this work, β-thiogalactoside mimetics bearing 1,1-diarylmethylene or benzophenone aglycons have been prepared and assayed for their affinity towards LecA, a lectin and virulence factor from Pseudomonas aeruginosa involved in bacterial adhesion and biofilm formation. The hit compound presents higher efficiency than previously described monovalent inhibitors and the crystal structure confirmed the occurrence of additional contacts between the aglycone and the protein surface. The highest affinity (160 nM) was obtained for a divalent ligand containing two galactosides.

Extending Janus lectins architecture: Characterization and application to protocells.

Synthetic biology is a rapidly growing field with applications in biotechnology and biomedicine. Through various approaches, remarkable achievements, such as cell and tissue engineering, have been already accomplished. In synthetic glycobiology, the engineering of glycan binding proteins is being exploited for producing tools with precise topology and specificity.

Neutralizing the Impact of the Virulence Factor LecA from Pseudomonas aeruginosa on Human Cells with New Glycomimetic Inhibitors.

Bacterial adhesion, biofilm formation and host cell invasion of the ESKAPE pathogen Pseudomonas aeruginosa require the tetravalent lectins LecA and LecB, which are therefore drug targets to fight these infections. Recently, we have reported highly potent divalent galactosides as specific LecA inhibitors. However, they suffered from very low solubility and an intrinsic chemical instability due to two acylhydrazone motifs, which precluded further biological evaluation.

Involvement of sialoglycans in SARS-COV-2 infection: Opportunities and challenges for glyco-based inhibitors.

Viral infections have been the causes of global pandemics, including the ongoing coronavirus disease 2019, which prompted the investigation into the infection mechanisms to find treatment and aid the vaccine design. Betacoronaviruses use spike glycoprotein on their surface to bind to host receptors, aiding their host attachment and cell fusion. Protein-glycan interaction has been implicated in the viral entry mechanism of many viruses and has recently been shown in SARS-CoV-2.

Discovery of -β-l-Fucosyl Amides as High-Affinity Ligands for the Lectin LecB.

The Gram-negative pathogen causes severe infections mainly in immunocompromised or cystic fibrosis patients and is able to resist antimicrobial treatments. The extracellular lectin LecB plays a key role in bacterial adhesion to the host and biofilm formation. For the inhibition of LecB, we designed and synthesized a set of fucosyl amides, sulfonamides, and thiourea derivatives.

Building an Artificial Plant Cell Wall on a Lipid Bilayer by Assembling Polysaccharides and Engineered Proteins.

The cell wall constitutes a fundamental structural component of plant cells, providing them with mechanical resistance and flexibility. Mimicking this wall is a critical step in the conception of an experimental model of the plant cell. The assembly of cellulose/hemicellulose in the form of cellulose nanocrystals and xyloglucans as a representative model of the plant cell wall has already been mastered; however, these models lacked the pectin component.

Targeting a Multidrug-Resistant Pathogen: First Generation Antagonists of 's BC2L-C Lectin.

Multidrug-resistant pathogens such as have become a hazard in the context of healthcare-associated infections, especially for patients admitted with cystic fibrosis or immuno-compromising conditions. Like other opportunistic Gram-negative bacteria, this pathogen establishes virulence and biofilms through lectin-mediated adhesion. In particular, the BC2L-C is believed to cross-link human epithelial cells to during pulmonary infections.

The choanoflagellate pore-forming lectin SaroL-1 punches holes in cancer cells by targeting the tumor-related glycosphingolipid Gb3.

Choanoflagellates are primitive protozoa used as models for animal evolution. They express a large variety of multi-domain proteins contributing to adhesion and cell communication, thereby providing a rich repertoire of molecules for biotechnology. Adhesion often involves proteins adopting a β-trefoil fold with carbohydrate-binding properties therefore classified as lectins.

Degradable Glycopolyester-like Nanoparticles by Radical Ring-Opening Polymerization.

A small library of degradable polyester-like glycopolymers was successfully prepared by the combination of radical ring-opening copolymerization of 2-methylene-1,3-dioxepane as a cyclic ketene acetal (CKA) with vinyl ether (VE) derivatives and a Pd-catalyzed thioglycoconjugation. The resulting thioglycopolymers were formulated into self-stabilized thioglyconanoparticles, which were stable up to 4 months and were enzymatically degraded. Nanoparticles and their degradation products exhibited a good cytocompatibility on two healthy cell lines.

A Bacterial Mannose Binding Lectin as a Tool for the Enrichment of C- and O-Mannosylated Peptides.

Mass spectrometry (MS) easily detects C-mannosylated peptides from purified proteins but not from complex biological samples. Enrichment of specific glycopeptides by lectin affinity prior to MS analysis has been widely applied to support glycopeptide identification but was until now not available for C-mannosylated peptides. Here, we used the α-mannose-specific lectin A (BC2L-A) and show that, in addition to its previously demonstrated high-mannose N-glycan binding capability, this lectin is able to retain C- and O-mannosylated peptides.

The Lectin LecB Induces Patches with Basolateral Characteristics at the Apical Membrane to Promote Pseudomonas aeruginosa Host Cell Invasion.

The opportunistic bacterium Pseudomonas aeruginosa can infect mucosal tissues of the human body. To persist at the mucosal barrier, this highly adaptable pathogen has evolved many strategies, including invasion of host cells. Here, we show that the P.

Lipopolysaccharides at Solid and Liquid Interfaces: Models for Biophysical Studies of the Gram-negative Bacterial Outer Membrane.

Lipopolysaccharides (LPSs) are a constitutive element of the cell envelope of Gram-negative bacteria, representing the main lipid in the external leaflet of their outer membrane (OM) lipid bilayer. These unique surface-exposed glycolipids play a central role in the interactions of Gram-negative organisms with their surrounding environment and represent a key element for protection against antimicrobials and the development of antibiotic resistance. The biophysical investigation of a wide range of different types of in vitro model membranes containing reconstituted LPS has revealed functional and structural properties of these peculiar membrane lipids, providing molecular-level details of their interaction with antimicrobial compounds.

Neutron crystallography reveals mechanisms used by Pseudomonas aeruginosa for host-cell binding.

The opportunistic pathogen Pseudomonas aeruginosa, a major cause of nosocomial infections, uses carbohydrate-binding proteins (lectins) as part of its binding to host cells. The fucose-binding lectin, LecB, displays a unique carbohydrate-binding site that incorporates two closely located calcium ions bridging between the ligand and protein, providing specificity and unusually high affinity. Here, we investigate the mechanisms involved in binding based on neutron crystallography studies of a fully deuterated LecB/fucose/calcium complex.