Fluorinated Carbohydrates as Lectin Ligands: Simultaneous Screening of a Monosaccharide Library and Chemical Mapping by ¹⁹F NMR Spectroscopy

Abstract

Molecular recognition of carbohydrates is a key step in essential biological processes. Carbohydrate receptors can distinguish monosaccharides even if they only differ in a single aspect of the orientation of the hydroxyl groups or harbor subtle chemical modifications. Hydroxyl-by-fluorine substitution has proven its merits for chemically mapping the importance of hydroxyl groups in carbohydrate–receptor interactions. 19 F NMR spectroscopy could thus be adapted to allow contact mapping together with screening in compound mixtures. Using a library of fluorinated glucose (Glc), mannose (Man), and galactose (Gal) derived by systematically exchanging every hydroxyl group by a fluorine atom, we developed a strategy combining chemical mapping and 19 F NMR T 2 filtering-based screening. By testing this strategy on the proof-of-principle level with a library of 13 fluorinated monosaccharides to a set of three carbohydrate receptors of diverse origin, i.e. the human macrophage galactose-type lectin, a plant lectin, Pisum sativum agglutinin, and the bacterial Gal-/Glc-binding protein from Escherichia coli , it became possible to simultaneously define their monosaccharide selectivity and identify the essential hydroxyls for interaction.

Hydrogen Bond Acceptor Propensity of Different Fluorine Atom Types: An Analysis of Experimentally and Computationally Derived Parameters

“…Although less abundant, alkyl fluorinated motifs are now receiving increasing consideration. For example, they are now included in fluorinated fragment libraries for 19 F NMR screening [43,55–57] . These molecules have a higher degree of three‐dimensionality, often improved solubility in water [4,18,40] and the alkyl fluorine atom can participate in polar intramolecular and intermolecular interactions which have important implications for the chemical‐physical and structural properties of the molecules, [58–73] chemical reactions [13,38,74–79] and protein–ligand recognition [39,80] .…”

“…For example, they are now included in fluorinated fragment libraries for 19 F NMR screening. [43,[55][56][57] These molecules have a higher degree of three-dimensionality, often improved solubility in water [4,18,40] and the alkyl fluorine atom can participate in polar intramolecular and intermolecular interactions which have important implications for the chemical-physical and structural properties of the molecules, [58][59][60][61][62][63][64][65][66][67][68][69][70][71][72][73] chemical reactions [13,38,[74][75][76][77][78][79] and protein-ligand recognition. [39,80] An example of this last point is the shielded alkyl mono-fluorinated tertiary motif contained in the prodrug sofosbuvir which is used for the treatment of chronic hepatitis C virus (HCV) infection.…”

Modulating the Efficacy of Carbonic Anhydrase Inhibitors through Fluorine Substitution

“…In this context, multiple approaches such as ITC,k inetic and inhibition studies,X-ray crystallography,and NMR spectroscopy are useful in dissecting single binding contributions to the overall observed effect. [92,101,102] There is no doubt that the exploitation of innovative directions in the field of protein and ligand-based screening by 19 FNMR spectroscopy [92,103] will allow misconduct to be avoided and also allow selective fluorine atom insertion to be finely tuned in the future.…”

Automatisierte Glykan‐Assemblierung 19F‐markierter Glykansonden ermöglicht Hochdurchsatz‐NMR‐Untersuchungen von Protein‐Glykan‐Interaktionen

“…Angesichts der großen Streuung von 19 F-NMR-Signalen kçnnen Bibliotheken von F-Glykanen mit unterschiedlichen chemischen Verschiebungen entworfen werden, um den Durchsatz dieses Ansatzes weiter zu erhçhen. [76] Die Fähigkeit von 19 F-Glykansonden, Bindungen oder enzymatische Umwandlungen in Lçsung und in Echtzeit aufzudecken, kçnnte den Wegf ürN MR-Anwendungen innerhalb von lebenden Zellen (in-cell NMR) ebnen, die oft das Problem hoher Hintergrundsignale zeigen. [14,77,78] Insgesamt sind diese Sonden wertvolle Werkzeuge,u me in besseres molekulares Verständnis der Wechselwirkungen von komplexen Glykanen mit Proteinrezeptoren zu erhalten.…”