Inhibition binding studies of glycodendrimer/lectin interactions using surface plasmon resonance

Schlick, Kristian H.; Cloninger, Mary J.

doi:10.1016/j.tet.2010.05.038

Cited by 35 publications

(20 citation statements)

References 40 publications

(39 reference statements)

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“…Binding occurs more readily if the carbohydrate terminated species is taller than the diluting species in the mixed SAM. [40] Methods employed in these studies have included surface plasmon resonance, [14, 31–33, 41–44] using both propagating surface plasmons on flat gold films and also localized surface plasmon resonance on gold nanoparticles supported on solid substrates, [45, 46] electrochemical impedance studies, [47] microgravimetric analysis, [48] and anodic stripping of nanoparticle labels using square-wave voltammetry. [49] In the case of mixed SAMs on gold nanoparticles on screen-printed electrodes, use of 3-mercapto-1-propanesulfonate as the diluent was successful at limiting non-specific protein adsorption and providing a good impedance response to Con A binding to a short chain mannose derivative.…”

Section: Introductionmentioning

confidence: 99%

Comparative Study of the Binding of Concanavalin A to Self-Assembled Monolayers Containing a Thiolated α-Mannoside on Flat Gold and on Nanoporous Gold

Pandey

Tan

Fujikawa

et al. 2012

Journal of Carbohydrate Chemistry

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We have prepared SAMs containing 8-mercaptooctyl α-D-mannopyranoside, either as a single component or in mixed SAMs with n-octanethiol on flat gold surfaces and on nanoporous gold. Electrochemical impedance spectroscopy showed that the mixed SAMs on flat gold surfaces showed the highest Con A binding near 1:9 solution molar ratio of thiolatedα-mannoside to n-octanethiol whereas those on NPG showed the highest response at 1:19 solution molar ratio of thiolated α-mannoside to n-octanethiol. Atomic force microscopy was employed to image the monolayers, and also to image the bound Con A protein.

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Section: Introductionmentioning

confidence: 99%

Comparative Study of the Binding of Concanavalin A to Self-Assembled Monolayers Containing a Thiolated α-Mannoside on Flat Gold and on Nanoporous Gold

Pandey

Tan

Fujikawa

et al. 2012

Journal of Carbohydrate Chemistry

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“…We used surface plasmon resonance (SPR), which measures the kinetics of association and dissociation of proteins on surfaces, to estimate the changes in free energies, because it is a well-established technique for studying multivalent interactions. 27 Scheme 1d diagrams the bivalent association and dissociation of (CA) 2 ’s to SAMs as a process that involves two steps—although, in principle, comparison of the thermodynamics of monovalent and bivalent binding does not require separate analysis of these steps. An equation analogous to equation 3 describes the equilibrium constant for the monovalent association of a bivalent receptor (CA) 2 to a ligand tethered to a surface (eq 4).…”

Section: Introductionmentioning

confidence: 99%

Using Covalent Dimers of Human Carbonic Anhydrase II To Model Bivalency in Immunoglobulins

et al. 2011

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This paper describes the development of a new bivalent system comprising synthetic dimers of carbonic anhydrase linked chemically through thiol groups of cysteine residues introduced by site-directed mutagenesis. These compounds serve as models with which to study the interaction of bivalent proteins with ligands presented at the surface of mixed self-assembled monolayers (SAMs). Monovalent carbonic anhydrase (CA) binds to benzenesulfonamide ligands presented on the surface of the SAM with Kdsurf = 89 nM. The synthetic bivalent proteins—inspired by the structure of immunoglobulins—bind bivalently to the sulfonamide-functionalized SAMs with low nanomolar avidities (Kdavidity, surf = 1 – 3 nM); this difference represents a ~50-fold enhancement of bivalent over monovalent association. The paper describes dimers of CA having i) different lengths of the covalent linker that joined the two proteins, and ii) different points of attachment of the linker to the protein (either near the active site (C133) or distal to the active site (C185)). Comparison of the thermodynamics of their interactions with SAMs presenting arylsulfonamide groups demonstrated that varying the length of the linker between the molecules of CA had virtually no effect on the rate or avidity of association, or on the avidity of these dimers with ligand-presenting surfaces. Varying the point of attachment of the linker between monomeric CA’s also had almost no effect on the avidity of the dimers, although changing the point of attachment affected the rates of binding and unbinding. These observations indicate that the avidity of these bivalent proteins, and by inference the avidities of structurally similar bivalent proteins such as IgG, are unexpectedly insensitive to the structure of the linker connecting them.

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“…We, and others, then realized that some aspects of cell surface mediated immuno-regulation depended upon co-operative electrostatic interactions between carbohydrates and proteins [35], [36]. This has now been shown to be the case for the receptor-ligand interaction between TLR4 and LPS by the demonstration of an exponential increase in binding affinity [37].…”

Section: Resultsmentioning

confidence: 94%

Partially Glycosylated Dendrimers Block MD-2 and Prevent TLR4-MD-2-LPS Complex Mediated Cytokine Responses

et al. 2011

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The crystal structure of the TLR4-MD-2-LPS complex responsible for triggering powerful pro-inflammatory cytokine responses has recently become available. Central to cell surface complex formation is binding of lipopolysaccharide (LPS) to soluble MD-2. We have previously shown, in biologically based experiments, that a generation 3.5 PAMAM dendrimer with 64 peripheral carboxylic acid groups acts as an antagonist of pro-inflammatory cytokine production after surface modification with 8 glucosamine molecules. We have also shown using molecular modelling approaches that this partially glycosylated dendrimer has the flexibility, cluster density, surface electrostatic charge, and hydrophilicity to make it a therapeutically useful antagonist of complex formation. These studies enabled the computational study of the interactions of the unmodified dendrimer, glucosamine, and of the partially glycosylated dendrimer with TLR4 and MD-2 using molecular docking and molecular dynamics techniques. They demonstrate that dendrimer glucosamine forms co-operative electrostatic interactions with residues lining the entrance to MD-2's hydrophobic pocket. Crucially, dendrimer glucosamine interferes with the electrostatic binding of: (i) the 4′phosphate on the di-glucosamine of LPS to Ser118 on MD-2; (ii) LPS to Lys91 on MD-2; (iii) the subsequent binding of TLR4 to Tyr102 on MD-2. This is followed by additional co-operative interactions between several of the dendrimer glucosamine's carboxylic acid branches and MD-2. Collectively, these interactions block the entry of the lipid chains of LPS into MD-2's hydrophobic pocket, and also prevent TLR4-MD-2-LPS complex formation. Our studies have therefore defined the first nonlipid-based synthetic MD-2 antagonist using both animal model-based studies of pro-inflammatory cytokine responses and molecular modelling studies of a whole dendrimer with its target protein. Using this approach, it should now be possible to computationally design additional macromolecular dendrimer based antagonists for other Toll Like Receptors. They could be useful for treating a spectrum of infectious, inflammatory and malignant diseases.

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Inhibition binding studies of glycodendrimer/lectin interactions using surface plasmon resonance

Cited by 35 publications

References 40 publications

Comparative Study of the Binding of Concanavalin A to Self-Assembled Monolayers Containing a Thiolated α-Mannoside on Flat Gold and on Nanoporous Gold

Comparative Study of the Binding of Concanavalin A to Self-Assembled Monolayers Containing a Thiolated α-Mannoside on Flat Gold and on Nanoporous Gold

Using Covalent Dimers of Human Carbonic Anhydrase II To Model Bivalency in Immunoglobulins

Partially Glycosylated Dendrimers Block MD-2 and Prevent TLR4-MD-2-LPS Complex Mediated Cytokine Responses

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