12 research outputs found
Multivalent glycan arrays
Glycan microarrays have become a powerful technology to study biological processes, such as cellâcell interaction, inflammation, and infections. Yet, several challenges, especially in multivalent display, remain. In this introductory lecture we discuss the state-of-the-art glycan microarray technology, with emphasis on novel approaches to access collections of pure glycans and their immobilization on surfaces. Future directions to mimic the natural glycan presentation on an array format, as well as in situ generation of combinatorial glycan collections, are discussed
VaporSPOT: Parallel Synthesis of Oligosaccharides on Membranes
Automated chemical synthesis has revolutionized synthetic access to biopolymers in terms of simplicity and speed. While automated oligosaccharide synthesis has become faster and more versatile, the parallel synthesis of oligosaccharides is not yet possible. Here, a chemical vapor glycosylation strategy (VaporSPOT) is described that enables the simultaneous synthesis of oligosaccharides on a cellulose membrane solid support. Different linkers allow for flexible and straightforward cleavage, purification, and characterization of the target oligosaccharides. This method is the basis for the development of parallel automated glycan synthesis platforms
Automated LaserâTransfer Synthesis of HighâDensity Microarrays for Infectious Disease Screening
Laser-induced forward transfer (LIFT) is a rapid laser-patterning technique for high-throughput combinatorial synthesis directly on glass slides. A lack of automation and precision limits LIFT applications to simple proof-of-concept syntheses of fewer than 100 compounds. Here, an automated synthesis instrument is reported that combines laser transfer and robotics for parallel synthesis in a microarray format with up to 10â000 individual reactions cmâ2. An optimized pipeline for amide bond formation is the basis for preparing complex peptide microarrays with thousands of different sequences in high yield with high reproducibility. The resulting peptide arrays are of higher quality than commercial peptide arrays. More than 4800 15-residue peptides resembling the entire Ebola virus proteome on a microarray are synthesized to study the antibody response of an Ebola virus infection survivor. Known and unknown epitopes that serve now as a basis for Ebola diagnostic development are identified. The versatility and precision of the synthesizer is demonstrated by in situ synthesis of fluorescent molecules via Schiff base reaction and multi-step patterning of precisely definable amounts of fluorophores. This automated laser transfer synthesis approach opens new avenues for high-throughput chemical synthesis and biological screening
Complications of chronic liver disease
Children with chronic liver disease (CLD) need a head to toe approach and an early suspicion of multi organ involvement. Nutritional assessment and management is the cornerstone of management. Consider immune dysfunction in everyday treatment decisions. Consider early heart-lung-brain involvement in transplant evaluation
Automated Laser-Transfer Synthesis of High-Density Microarrays for Infectious Disease Screening
Laser-induced forward transfer (LIFT) is a rapid laser-patterning technique for high-throughput combinatorial synthesis directly on glass slides. A lack of automation and precision limits LIFT applications to simple proof-of-concept syntheses of fewer than 100 compounds. Here, an automated synthesis instrument is reported that combines laser transfer and robotics for parallel synthesis in a microarray format with up to 10â000 individual reactions cmâ2. An optimized pipeline for amide bond formation is the basis for preparing complex peptide microarrays with thousands of different sequences in high yield with high reproducibility. The resulting peptide arrays are of higher quality than commercial peptide arrays. More than 4800 15-residue peptides resembling the entire Ebola virus proteome on a microarray are synthesized to study the antibody response of an Ebola virus infection survivor. Known and unknown epitopes that serve now as a basis for Ebola diagnostic development are identified. The versatility and precision of the synthesizer is demonstrated by in situ synthesis of fluorescent molecules via Schiff base reaction and multi-step patterning of precisely definable amounts of fluorophores. This automated laser transfer synthesis approach opens new avenues for high-throughput chemical synthesis and biological screening
Probing Multivalent Carbohydrate-Protein Interactions With On-Chip Synthesized Glycopeptides Using Different Functionalized Surfaces
Multivalent ligandâprotein interactions are a commonly employed approach by nature in many biological processes. Single glycanâprotein interactions are often weak, but their affinity and specificity can be drastically enhanced by engaging multiple binding sites. Microarray technology allows for quick, parallel screening of such interactions. Yet, current glycan microarray methodologies usually neglect defined multivalent presentation. Our laser-based array technology allows for a flexible, cost-efficient, and rapid in situ chemical synthesis of peptide scaffolds directly on functionalized glass slides. Using copper(I)-catalyzed azideâalkyne cycloaddition, different monomer sugar azides were attached to the scaffolds, resulting in spatially defined multivalent glycopeptides on the solid support. Studying their interaction with several different lectins showed that not only the spatially defined sugar presentation, but also the surface functionalization and wettability, as well as accessibility and flexibility, play an essential role in such interactions. Therefore, different commercially available functionalized glass slides were equipped with a polyethylene glycol (PEG) linker to demonstrate its effect on glycanâlectin interactions. Moreover, different monomer sugar azides with and without an additional PEG-spacer were attached to the peptide scaffold to increase flexibility and thereby improve binding affinity. A variety of fluorescently labeled lectins were probed, indicating that different lectinâglycan pairs require different surface functionalization and spacers for enhanced binding. This approach allows for rapid screening and evaluation of spacing-, density-, ligand and surface-dependent parameters, to find optimal lectin binders.BMBF, 13XP5050A, Erforschung einer neuen Methode fĂŒr die Herstellung von hochdichten MolekĂŒlbibliotheken (cLIFT
OnâChip NeoâGlycopeptide Synthesis for Multivalent Glycan Presentation
Single glycanâprotein interactions are often weak, such that glycan binding partners commonly utilize multiple, spatially defined binding sites to enhance binding avidity and specificity. Current array technologies usually neglect defined multivalent display. Laserâbased array synthesis technology allows for flexible and rapid onâsurface synthesis of different peptides. By combining this technique with click chemistry, neoâglycopeptides were produced directly on a functionalized glass slide in the microarray format. Density and spatial distribution of carbohydrates can be tuned, resulting in wellâdefined glycan structures for multivalent display. The two lectins concanavalin A and langerin were probed with different glycans on multivalent scaffolds, revealing strong spacingâ, densityâ, and ligandâdependent binding. In addition, we could also measure the surface dissociation constant. This approach allows for a rapid generation, screening, and optimization of a multitude of multivalent scaffolds for glycan binding
On-Chip Neo-Glycopeptide Synthesis for Multivalent Glycan Presentation
Single glycan-protein interactions are often weak, such that glycan binding partners commonly utilize multiple, spatially defined binding sites to enhance binding avidity and specificity. Current array technologies usually neglect defined multivalent display. Laser-based array synthesis technology allows for flexible and rapid on-surface synthesis of different peptides. By combining this technique with click chemistry, neo-glycopeptides were produced directly on a functionalized glass slide in the microarray format. Density and spatial distribution of carbohydrates can be tuned, resulting in well-defined glycan structures for multivalent display. The two lectins concanavalin A and langerin were probed with different glycans on multivalent scaffolds, revealing strong spacing-, density-, and ligand-dependent binding. In addition, we could also measure the surface dissociation constant. This approach allows for a rapid generation, screening, and optimization of a multitude of multivalent scaffolds for glycan binding
Salivary adiponectin levels are associated with training intensity but not with bone mass or reproductive function in elite Rhythmic Gymnasts
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