Interaction of saccharide haptens with myeloma proteins. A 270-MHz proton NMR study

Gettins, Peter G.W.; Boyd, Jonathan; Glaudemans, Cornelis P.J.; Potter, Michael; Dwek, Raymond A.

doi:10.1021/bi00529a021

Cited by 12 publications

(5 citation statements)

References 40 publications

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“…The shape and topology of these subsites determine the specificity for a particular 3D arrangement of sugars (18). In the case of gp120, it is possible to construct a novel sugar epitope (i.e., nonself) from the tight clustering of the different oligomannose structures on the silent face of gp120.…”

Section: Vol 76 2002mentioning

confidence: 99%

The Broadly Neutralizing Anti-Human Immunodeficiency Virus Type 1 Antibody 2G12 Recognizes a Cluster of α1→2 Mannose Residues on the Outer Face of gp120

Scanlan

Pantophlet²,

Wormald

et al. 2002

J Virol

649

667

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2G12 is a broadly neutralizing human monoclonal antibody against human immunodeficiency virus type-1 (HIV-1) that has previously been shown to bind to a carbohydrate-dependent epitope on gp120. Here, sitedirected mutagenesis and carbohydrate analysis were used to define further the 2G12 epitope. Extensive alanine scanning mutagenesis showed that elimination of the N-linked carbohydrate attachment sequences associated with residues N295, N332, N339, N386, and N392 by N3A substitution produced significant decreases in 2G12 binding affinity to gp120 JR-CSF . Further mutagenesis suggested that the glycans at N339 and N386 were not critical for 2G12 binding to gp120 JR-CSF . Comparison of the sequences of isolates neutralized by 2G12 was also consistent with a lesser role for glycans attached at these positions. The mutagenesis studies provided no convincing evidence for the involvement of gp120 amino acid side chains in 2G12 binding. Antibody binding was inhibited when gp120 was treated with Aspergillus saitoi mannosidase, Jack Bean mannosidase, or endoglycosidase H, indicating that Man␣132Man-linked sugars of oligomannose glycans on gp120 are required for 2G12 binding. Consistent with this finding, the binding of 2G12 to gp120 could be inhibited by monomeric mannose but not by galactose, glucose, or N-acetylglucosamine. The inability of 2G12 to bind to gp120 produced in the presence of the glucose analogue N-butyl-deoxynojirimycin similarly implicated Man␣132Man-linked sugars in 2G12 binding. Competition experiments between 2G12 and the lectin cyanovirin for binding to gp120 showed that 2G12 only interacts with a subset of available Man␣132Man-linked sugars. Consideration of all the data, together with inspection of a molecular model of gp120, suggests that the most likely epitope for 2G12 is formed from mannose residues contributed by the glycans attached to N295 and N332, with the other glycans playing an indirect role in maintaining epitope conformation.

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Section: Vol 76 2002mentioning

confidence: 99%

The Broadly Neutralizing Anti-Human Immunodeficiency Virus Type 1 Antibody 2G12 Recognizes a Cluster of α1→2 Mannose Residues on the Outer Face of gp120

Scanlan

Pantophlet²,

Wormald

et al. 2002

J Virol

649

667

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“…The conformational flexibility of antigenic determinants, and the possible selection of one of these conformations as the one to be recognized by its antibody, has been the object of many studies (Vuk- Pavlovic et al, 1978;Gettins et al, 1981;Tainer et al, 1984;Amit et al, 1986;Colman et al, 1987;Davies et al, 1988). For oligosaccharide epitopes, theoretical considerations have been advanced for the prediction of solution conformations (Lemieux & Bock, 1983).…”

mentioning

confidence: 99%

“…NMR spectroscopy has also been used to study antibody-antigen complexes. For example, changes in chemical shifts of histidine protons have been monitored to determine which histidine residues were perturbed upon binding of hapten (Gettins et al, 1981).…”

mentioning

confidence: 99%

Significant conformational changes in an antigenic carbohydrate epitope upon binding to a monoclonal antibody

Glaudemans¹,

Lerner²,

Daves³

et al. 1990

Biochemistry

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Transferred nuclear Overhauser enhancement spectroscopy (TRNOE) was used to observe changes in a ligand's conformation upon binding to its specific antibody. The ligands studied were methyl O-beta-D-galactopyranosyl(1----6)-4-deoxy-4-fluoro-beta-D-galactopyra nos ide (me4FGal2) and its selectively deuteriated analogue, methyl O-beta-D-galactopyranosyl(1----6)-4-deoxy-2-deuterio-4-fluoro-beta -D- galactopyranoside (me4F2dGal2). The monoclonal antibody was mouse IgA X24. The solution conformation of the free ligand me4F2dGal2 was inferred from measurements of vicinal 1H-1H coupling constants, long-range 1H-13C coupling constants, and NOE cross-peak intensities. For free ligand, both galactosyl residues adopt a regular chair conformation, but the NMR spectra are incompatible with a single unique conformation of the glycosidic linkage. Analysis of 1H-1H and 1H-13C constants indicates that the major conformer has an extended conformation: phi = -120 degrees; psi = 180 degrees; and omega = 75 degrees. TRNOE measurements on me4FGal2 and me4F2dGal2 in the presence of the specific antibody indicate that the pyranose ring pucker of each galactose ring remains unchanged, but rotations about the glycosidic linkage occur upon binding to X24. Computer calculations indicate that there are two sets of torsion angles that satisfy the observed NMR constraints, namely, phi = -152 +/- 9 degrees; psi = -128 +/- 7 degrees; and omega = -158 +/- 6 degrees; and a conformer with phi = -53 +/- 6 degrees; psi = 154 +/- 10 degrees; and omega = -173 +/- 6 degrees. Neither conformation is similar to any of the observed conformations of the free disaccharide.(ABSTRACT TRUNCATED AT 250 WORDS)

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“…Pathogens which present specific oligosaccharides as repetitive arrays can, if these arrays have a suitable geometry, activate multivalent receptors. One example is MBL, which is involved in the recognition and subsequent elimination of pathogens through interaction with carbohydrates on the pathogen (Gettins et al, 1981;Weis et al, 1998;Rudd et al, 2001). This means that selectivity of CBA to pathogens, in ©2007 International Medical Press particular viruses, may become an achievable goal.…”

Section: Potential Pitfalls Of Cba To Be Used As Therapeutic Agentsmentioning

confidence: 99%

Carbohydrate-Binding Agents: A Potential Future Cornerstone for the Chemotherapy of Enveloped Viruses?

Balzarini

2007

Antivir Chem Chemother

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Carbohydrate-binding agents (CBAs) inhibit HIV-1 and it is proposed that therapy with such agents may have important implications for the future of anti-HIV therapy. Examples of CBAs include the procaryotic cyanovirin-N (CV-N), plant lectins such as HHA, GNA, NPA, CA and UDA, the monoclonal antibody 2G12 directed against a glycan-containing epitope on HIV envelope gp120, and the mannose-specific non-peptidic antibiotic Pradimicin A, which inhibits the entry of HIV-1 into its target cells. CBAs prevent not only virus infection of susceptible cells, but also inhibit syncytia formation between persistently HIV-infected cells and uninfected lymphocytes. In addition, CBAs may also prevent DC-SIGN-mediated transmission of HIV to T-lymphocytes. Therefore, CBAs qualify as potential microbicide drugs. Long-term exposure of HIV to CBAs in cell culture results in the progressive deletion of N-glycans of HIV gpl20 in an attempt of the virus to escape drug pressure. In this respect, the CBAs are endowed with a high genetic barrier. Multiple mutations at N-glycosylation sites are required before pronounced phenotypic drug resistance development becomes evident. CBA treatment of HIV may consist of a novel chemotherapeutic concept with a dual mechanism of antiviral action: a direct antiviral activity by preventing HIV entry and transmission to its target cells, and an indirect antiviral activity by forcing HIV to delete glycans in its gpl20 envelope. The latter phenomenon will result in creating 'holes' in the protective glycan shield of the HIV envelope, whereby the immune system may become triggered to produce neutralizing antibodies against previously hidden immunogenic epitopes of gp120. If this concept can be proven in in vivo, low-molecular-weight non-peptidic CBAs such as Pradimycin A may become the cornerstone for the efficient treatment of infections of those viruses that require a glycosylated envelope (that is, HIV, but also hepatitis C virus) for entry into its target cells. In addition, influenza virus and coronavirus infections may also qualify to be treated by CBAs.

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Interaction of saccharide haptens with myeloma proteins. A 270-MHz proton NMR study

Cited by 12 publications

References 40 publications

The Broadly Neutralizing Anti-Human Immunodeficiency Virus Type 1 Antibody 2G12 Recognizes a Cluster of α1→2 Mannose Residues on the Outer Face of gp120

The Broadly Neutralizing Anti-Human Immunodeficiency Virus Type 1 Antibody 2G12 Recognizes a Cluster of α1→2 Mannose Residues on the Outer Face of gp120

Significant conformational changes in an antigenic carbohydrate epitope upon binding to a monoclonal antibody

Carbohydrate-Binding Agents: A Potential Future Cornerstone for the Chemotherapy of Enveloped Viruses?

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