A Synthetic Lectin for O‐Linked β‐N‐Acetylglucosamine

Abstract

Changing employment: Receptor 1 binds β‐N‐acetylglucosaminyl (β‐GlcNAc) up to 100 times more strongly than it does glucose. This synthetic lectin shows affinities similar to wheat germ agglutinin (WGA), a natural lectin used to bind GlcNAc. Remarkably, 1 is more selective than WGA. It favors especially the glycoside unit in glycopeptide 2, a model of the serine‐O‐GlcNAc posttranslational protein modification.

Van Der Waals Interactions and the Hydrophobic Effect

“…Recently disaccharides from water [122]. In particular, sugars with all equatorial arrays of polar substituents and hence apolar faces of axially directed CH groups show good affinity, a fact that has been utilized in a slightly smaller host that binds O-linked β-N -acetylglucosamine (O-GlcNAc) and related derivatives [123].…”

Progress in biomimetic carbohydrate recognition

“…d Disaccharide receptors 52a, b, with intended substrate cellobiose 29 *4.5:1). It was then realised that b-N-acetylglucosaminyl (b-GlcNAc, as in 15 and 32) might also be a good target, so a number of N-acetylaminosugars were added to the list of substrates [99]. The full set of binding constants, shown in Table 5, tells a remarkable story.…”

“…Glycopeptide 53 was prepared as a model of this unit and tested as a substrate for 51c [99]. Encouragingly, 53 was bound with K a = 1040 M -1 , slightly more strongly than methyl analogue 32.…”

“…Once again, the targeted all-equatorial substrates were bound with good affinities and excellent selectivities. The K a values for cellobiose 29, methyl b-Dcellobioside 38 and xylobiose 39 were *600, *900 and Table 5 Association constants (K a ) for binding of carbohydrates in water to tricyclic octa-amide receptor 51c, in order of descending affinity Data from [98] and [99] c For more information see [99] d Confirmed by isothermal titration calorimetry (ITC; K a = 635 M -1 ) e Measured by induced circular dichroism (ICD) f No change in spectrum on addition of carbohydrate *260 M -1 , respectively. N,N 0 -Diacetylchitobiose 37 was also bound quite well although in this case (unlike 51c) the NHAc groups seemed to lower affinity.…”

Investigation of protein–ligand interactions of targets with solvent exposed binding sites

“…Although the nature of peptide-ASF binding remained unrevealed in our work, the construction of artificial receptor structures for the recognition of carbohydrates is also a hot topic. 197,198 Ligand C aliphatic GS-STD approaches) revealed that the signal-intensity pattern of the difference spectra is affected by both the type and the spatial distribution of the excited 'transmitter' atoms, and also by the efficiency of the spin-diffusion-mediated magnetization transfer. …”