title: Monitoring Glycan-Protein Interactions by NMR Spectroscopic Analysis: A Simple Chemical Tag That Mimics Natural CH-π Interactions.
abstract: Detection of molecular recognition processes requires robust, specific, and easily implementable sensing methods, especially for screening applications. Here, we propose the difluoroacetamide moiety (an acetamide bioisoster) as a novel tag for detecting by NMR analysis those glycan-protein interactions that involve N-acetylated sugars. Although difluoroacetamide has been used previously as a substituent in medicinal chemistry, here we employ it as a specific sensor to monitor interactions between GlcNAc-containing glycans and a model lectin (wheat germ agglutinin). In contrast to the widely employed trifluoroacetamide group, the difluoroacetamide tag contains geminal (1) H and (19) F atoms that allow both (1) H and (19) F NMR methods for easy and robust detection of molecular recognition processes involving GlcNAc- (or GalNAc-) moieties over a range of binding affinities. The CHF2 CONH- moiety behaves in a manner that is very similar to that of the natural acetamide fragment in the involved aromatic-sugar interactions, providing analogous binding energy and conformations, whereas the perfluorinated CF3 CONH- analogue differs more significantly.
authors.affiliation: Department of Chemical and Physical Biology, CIB-CSIC, Ramiro de Maeztu 9, 28040 Madrid (Spain).
authors.forename: Luis P
authors.initials: LP
authors.lastname: Calle
authors.affiliation: Department of Glycotechnology, CICbiomaGUNE, Paseo Miramón 182, 20009 San Sebastián (Spain).
authors.forename: Begoña
authors.initials: B
authors.lastname: Echeverria
authors.affiliation: Department of Organic Chemistry, University of Sevilla, Profesor García González 1, 41012 Sevilla (Spain).
authors.forename: Antonio
authors.initials: A
authors.lastname: Franconetti
authors.affiliation: Department of Glycotechnology, CICbiomaGUNE, Paseo Miramón 182, 20009 San Sebastián (Spain).
authors.forename: Sonia
authors.initials: S
authors.lastname: Serna
authors.affiliation: Department of Chemical and Physical Biology, CIB-CSIC, Ramiro de Maeztu 9, 28040 Madrid (Spain).
authors.forename: M Carmen
authors.initials: MC
authors.lastname: Fernández-Alonso
authors.affiliation: Structural Biology Unit, CIC bioGUNE, Parque Tecnologico de Bizkaia, Building 801a, 48160 Derio (Spain).
authors.forename: Tammo
authors.initials: T
authors.lastname: Diercks
authors.affiliation: Department of Chemical and Physical Biology, CIB-CSIC, Ramiro de Maeztu 9, 28040 Madrid (Spain).
authors.forename: F Javier
authors.initials: FJ
authors.lastname: Cañada
authors.affiliation: Structural Biology Unit, CIC bioGUNE, Parque Tecnologico de Bizkaia, Building 801a, 48160 Derio (Spain).
authors.forename: Ana
authors.initials: A
authors.lastname: Ardá
authors.affiliation: Department of Glycotechnology, CICbiomaGUNE, Paseo Miramón 182, 20009 San Sebastián (Spain). nreichardt@cicbiomagune.es.
authors.forename: Niels-Christian
authors.initials: NC
authors.lastname: Reichardt
authors.affiliation: Structural Biology Unit, CIC bioGUNE, Parque Tecnologico de Bizkaia, Building 801a, 48160 Derio (Spain). jjbarbero@cicbiogune.es.|Ikerbasque, Basque Foundation for Science, 48013 Bilbao (Spain). jjbarbero@cicbiogune.es.
authors.forename: Jesús
authors.initials: J
authors.lastname: Jiménez-Barbero
mesh_terms: D000081:Acetamides / Q000737:chemistry*; D005461:Fluorine / Q000737:chemistry*; D005463:Fluoroacetates / Q000737:chemistry*; D006860:Hydrogen Bonding; D037102:Lectins / Q000378:metabolism; D009682:Magnetic Resonance Spectroscopy; D008958:Models, Molecular; D011134:Polysaccharides / Q000737:chemistry*
chemical_list: D000081:Acetamides; D005463:Fluoroacetates; D037102:Lectins; D011134:Polysaccharides; D005461:Fluorine; C030688:trifluoroacetamide
keywords: NMR spectroscopy; fluorine; molecular modeling; molecular recognition; noncovalent interactions