Specificity of isolectins of wheat germ agglutinin for sialyloligosaccharides: a 360-MHz proton NMR binding study

Ka, Kronis; Jp, Carver

doi:10.1021/bi00256a003

Cited by 101 publications

(58 citation statements)

References 37 publications

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“…This rationale would also explain the difference between binding scores of sites Blcz and C2,, in the WGAI/T5 complex (1,273 versus 1,346), where the u2,3-linked NeuNAc sits in site C2,,, and the a2.6 linked NeuNAc in site Blcr. AIthough these discrepancies are within what we believe to be the uncertainty of HINT data, they agree with earlier binding data (Kronis & Carver, 1982), and with the NeuLac/WGAI crystal structure revealing that stronger binding of a2,3-NeuLac is due to additional contacts involving Tyr 66 (Wright, 1990).…”

Section: Neunac Bindingsupporting

confidence: 90%

Differences in hydropathic properties of ligand binding at four independent sites in wheat germ agglutinin‐oligosaccharide crystal complexes

Wright

Kellogg

1996

Protein Science

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The binding interactions of N-acetyl-D-neuraminic acid and N,N' diacetyl-chitobiose (GlcNAc-fi-I,4-GlcNAc), observed in crystal complexes of wheat germ agglutinin (WGA) at four independent sites/monomer, were analyzed and compared with the modeling program HINT (Hydropathic INTeractions). This empirical method allows assessment of relative ligand binding strength and is particularly applicable to cases of weak binding where experimental data is absent. Although the four WGA binding sites are interrelated by a fourfold sequence repeat (eight sites/dimer), similarity extends only to the presence of an aromatic amino acid-rich pocket and a conserved serine. Strong binding requires additional interactions from a contacting domain in the second subunit. Ligand positions were either derived from crystal structures and further optimized by modeling and molecular mechanics, or from comparative modeling. Analysis of the overall HINT binding scores for the two types of ligands are consistent with the presence of two high-affinity and two low-affinity sites per monomer. Identity of these sites correlates well with crystal structure occupancies. The high-affinity sites are roughly equivalent, as predicted from solution binding studies. Binding scores for the low-affinity sites are weaker by at least a factor of two. Quantitative estimates for polar, nonpolar, and ionic interactions revealed that H-bonding makes the largest contribution to complex stabilization in the seven bound configurations, consistent with published thermodynamic data. Although the observed nonpolar interactions are small, they may play a critical role in orienting the ligand optimally.

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Section: Neunac Bindingsupporting

confidence: 90%

Differences in hydropathic properties of ligand binding at four independent sites in wheat germ agglutinin‐oligosaccharide crystal complexes

Wright

Kellogg

1996

Protein Science

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“…Further blotting studies and subsequent use of WGA agglutinin as a probe revealed that a glycoprotein S14 with an apparent molecular mass of 14 kDa was dominant among the released proteins. The specificity of this plant lectin had been attributed to the sugar moieties NeuNAc as well as GlcNAc (Kronis and Carver, 1982). Glycoproteins comprising those sugar residues occur frequently, from plants to metazoa (Karpati et al, 1999).…”

Section: Discussionmentioning

confidence: 96%

Biosilicification of loricate choanoflagellate: organic composition of the nanotubular siliceous costal strips of Stephanoeca diplocostata

Gong

Wiens

Schröder

et al. 2010

Journal of Experimental Biology

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SUMMARYLoricate choanoflagellates (unicellular, eukaryotic flagellates; phylum Choanozoa) synthesize a basket-like siliceous lorica reinforced by costal strips (diameter of approximately 100nm and length of 3m). In the present study, the composition of these siliceous costal strips is described, using Stephanoeca diplocostata as a model. Analyses by energy-dispersive X-ray spectroscopy (EDX), coupled with transmission electron microscopy (TEM), indicate that the costal strips comprise inorganic and organic components. The organic, proteinaceous scaffold contained one major polypeptide of mass 14kDa that reacted with wheat germ agglutinin. Polyclonal antibodies were raised that allowed mapping of the proteinaceous scaffold, the (glyco)proteins, within the costal strips. Subsequent in vitro studies revealed that the organic scaffold of the costal strips stimulates polycondensation of ortho-silicic acid in a concentration-and pH-dependent way. Taken together, the data gathered indicate that the siliceous costal strips are formed around a proteinaceous scaffold that supports and maintains biosilicification. A scheme is given that outlines that the organic template guides both the axial and the lateral growth of the strips.

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“…We can therefore conclude that a K d ϳ 30 M reflects the binding affinity of the lectin domain for ␣-Neu5Ac, which is a relatively high affinity for carbohydrate recognition. Wheat germ agglutinin (2CWG) has a K d ϳ 100 M with sialyllactose (40), but this also involves contributions from interactions of the galactose. Influenza virus hemagglutinin (5HMG) has a K d ϳ 1 mM with sialyllactose (41), as does the VP4 sialic acid binding domain of the rhesus rotavirus (1KQR) (34).…”

Section: Std Nmr Experiments To Investigate the Binding Of Neu59ac 2mentioning

confidence: 99%

Sialic Acid Recognition by Vibrio cholerae Neuraminidase

Moustafa

Connaris

Taylor

et al. 2004

Journal of Biological Chemistry

135

131

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Vibrio cholerae neuraminidase (VCNA) plays a significant role in the pathogenesis of cholera by removing sialic acid from higher order gangliosides to unmask GM1, the receptor for cholera toxin. We previously showed that the structure of VCNA is composed of a central ␤-propeller catalytic domain flanked by two lectin-like domains; however the nature of the carbohydrates recognized by these lectin domains has remained unknown. We present here structures of the enzyme in complex with two substrates, ␣-2,3-sialyllactose and ␣-2,6-sialyllactose. Both substrate complexes reveal the ␣-anomer of N-acetylneuraminic acid (Neu5Ac) bound to the N-terminal lectin domain, thereby revealing the role of this domain. The large number of interactions suggest a relatively high binding affinity for sialic acid, which was confirmed by calorimetry, which gave a K d ϳ 30 M. Saturation transfer difference NMR using a non-hydrolyzable substrate, Neu5,9Ac 2 -2-S-(␣-2,6)-GlcNAc␤1Me, was also used to map the ligand interactions at the VCNA lectin binding site. It is well known that VCNA can hydrolyze both ␣-2,3-and ␣-2,6-linked sialic acid substrates. In this study using ␣-2,3-sialyllactose co-crystallized with VCNA it was revealed that the inhibitor 2-deoxy-2,3-didehydro-N-acetylneuraminic acid (Neu5Ac2en) was bound at the catalytic site. This observation supports the notion that VCNA can produce its own inhibitor and has been further confirmed by 1 H NMR analysis. The discovery of the sialic acid binding site in the N-lectin-like domain suggests that this might help target VCNA to sialic acid-rich environments, thereby enhancing the catalytic efficiency of the enzyme.

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Specificity of isolectins of wheat germ agglutinin for sialyloligosaccharides: a 360-MHz proton NMR binding study

Cited by 101 publications

References 37 publications

Differences in hydropathic properties of ligand binding at four independent sites in wheat germ agglutinin‐oligosaccharide crystal complexes

Differences in hydropathic properties of ligand binding at four independent sites in wheat germ agglutinin‐oligosaccharide crystal complexes

Biosilicification of loricate choanoflagellate: organic composition of the nanotubular siliceous costal strips of Stephanoeca diplocostata

Sialic Acid Recognition by Vibrio cholerae Neuraminidase

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