NMR Studies of Carbohydrates and Carbohydrate-mimetic Peptides Recognized by an Anti-Group B Streptococcus Antibody

Johnson, Margaret; Jaseja, Mahesh; Zou, Wei; Jennings, Harold J.; Copié, Valérie; Pinto, B. Mario; Pincus, Seth H.

doi:10.1074/jbc.m301846200

Cited by 28 publications

(22 citation statements)

References 49 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Although p22 was found much more flexible than p115 or p100c, all three peptides adopted ␤-turn conformations, either of nonclassified type or of type I. This appears to be a rather common conformational feature for short peptides representative of antigenic regions of proteins (85) or polysaccharide antigens such as group A Streptococcus CP (9) and group B Streptococcus CP (38). Indeed, it has been suggested that a ␤-turn allows appropriate exposure of side chain residues for optimal fit within the mAb combining site.…”

Section: Discussionmentioning

confidence: 99%

“…Ligand Interaction with the Protective mIgAs-Investigation of the molecular pattern of the interactions involved in the peptide-and pentasaccharide-mIgA complexes relied on two complementary methodologies, namely trNOE and STD NMR experiments, whose combination was found to model accurately mAb-ligand interactions (38,47). Indeed, the former technique provides key information on the conformation of the bound ligand, whereas the latter allows epitope mapping via magnetization transfer from the protein to the residues of the ligand that are in close contact with the protein.…”

Section: Methodsmentioning

confidence: 99%

“…The conformational preferences observed for the peptides were tentatively related to those derived from NMR and molecular modeling analysis of the DA(E)BC-mIgA complexes that led to a theoretical model of the recognition of S. flexneri 5a O-SP by mIgA I3. This contribution adds to the few reports investigating molecular mimicry by analyzing both peptide mimic-mAb and carbohydrate-mAb recognition features (37)(38)(39).…”

mentioning

confidence: 99%

See 2 more Smart Citations

Toward a Better Understanding of the Basis of the Molecular Mimicry of Polysaccharide Antigens by Peptides

Clément

Fortuné

Phalipon

et al. 2006

Journal of Biological Chemistry

View full text Add to dashboard Cite

Protein conjugates of oligosaccharides or peptides that mimic complex bacterial polysaccharide antigens represent alternatives to the classical polysaccharide-based conjugate vaccines developed so far. Hence, a better understanding of the molecular basis ensuring appropriate mimicry is required in order to design efficient carbohydrate mimic-based vaccines. This study focuses on the following two unrelated sets of mimics of the Shigella flexneri 5a O-specific polysaccharide (O-SP): (i) a synthetic branched pentasaccharide known to mimic the average solution conformation of S. flexneri 5a O-SP, and (ii) three nonapeptides selected upon screening of phagedisplayed peptide libraries with two protective murine monoclonal antibodies (mAbs) of the A isotype specific for S. flexneri 5a O-SP. By inducing anti-O-SP antibodies upon immunization in mice when appropriately presented to the immune system, the pentasaccharide and peptides p100c and p115, but not peptide p22, were qualified as mimotopes of the native antigen. NMR studies based on transferred NOE (trNOE) experiments revealed that both kinds of mimotopes had an average conformation when bound to the mAbs that was close to that of their free form. Most interestingly, saturation transfer difference (STD) experiments showed that the characteristic turn conformations adopted by the major conformers of p100c and p115, as well as of p22, are clearly involved in mAb binding. These latter experiments also showed that the branched glucose residue of the pentasaccharide was a key part of the determinant recognized by the protective mAbs. Finally, by using NMRderived pentasaccharide and peptide conformations coupled to STD information, models of antigen-antibody interaction were obtained. Most interestingly, only one model was found compatible with experimental data when large O-SP fragments were docked into one of the mIgA-binding sites. This newly made available system provides a new contribution to the understanding of the molecular mimicry of complex polysaccharides by peptides and short oligosaccharides.

show abstract

Section: Discussionmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

mentioning

confidence: 99%

See 1 more Smart Citation

Toward a Better Understanding of the Basis of the Molecular Mimicry of Polysaccharide Antigens by Peptides

Clément

Fortuné

Phalipon

et al. 2006

Journal of Biological Chemistry

View full text Add to dashboard Cite

show abstract

“…Structural mimicry has been suggested (but not demonstrated) for peptide and carbohydrate ligands of anti-Lewis Y MAb BR55-2, using molecular modeling (52), and proposed for a peptide mimic of the group B streptococcal type III capsular polysaccharide by Pincus and colleagues (53,54). However, structures of both peptide and carbohydrate with the cognate antibody are not available.…”

Section: Discussionmentioning

confidence: 99%

A peptide inhibitor of HIV‐1 neutralizing antibody 2G12 is not a structural mimic of the natural carbohydrate epitope on gp120

Menéndez

Calarese

Stanfield³

et al. 2008

FASEB j.

View full text Add to dashboard Cite

MAb 2G12 neutralizes HIV-1 by binding with high affinity to a cluster of high-mannose oligosaccharides on the envelope glycoprotein, gp120. Screening of phage-displayed peptide libraries with 2G12 identified peptides that bind specifically, with K d s ranging from 0.4 to 200 μM. The crystal structure of a 21-mer peptide ligand in complex with 2G12 Fab was determined at 2.8 Å resolution. Comparison of this structure with previous structures of 2G12-carbohydrate complexes revealed striking differences in the mechanism of 2G12 binding to peptide vs. carbohydrate. The peptide occupies a site different from, but adjacent to, the primary carbohydrate-binding site on 2G12, and makes only slightly fewer contacts to the Fab than Man 9 GlcNAc 2 (51 vs. 56, respectively). However, only two antibody contacts with the peptide are hydrogen bonds in contrast to six with Man 9 GlcNAc 2 , and only three of the antibody residues that interact with Man 9 GlcNAc 2 also contact the peptide. Thus, this mechanism of peptide binding to 2G12 does not support structural mimicry of the native carbohydrate epitope on gp120, since it neither replicates the oligosaccharide footprint on the antibody nor most of the contact residues. Moreover, 2G12.1 peptide is not an immunogenic mimic of the 2G12 epitope, since antisera produced against it did not bind gp120.-Menendez, A., Calarese, D. A., Stanfield, R. L., Chow, K. C., Scanlan, C. N., Kunert, R., Katinger, H., Burton, D. R., Wilson, I. A., Scott, J. K. A peptide inhibitor of HIV-1 neutralizing antibody 2G12 is not a structural mimic of the natural carbohydrate epitope on gp120. NIH-PA Author ManuscriptNIH-PA Author Manuscript NIH-PA Author ManuscriptHuman monoclonal antibody (MAb) 2G12 efficiently neutralizes a broad range of HIV-1 primary isolates in vitro (1-3) and protects from in vivo viral challenge in macaques in combination with other antibodies (4-6). MAb 2G12 binds with high affinity to a unique, conserved epitope on the HIV-1 envelope that is formed by a cluster of N-linked, high-mannose glycan groups on the "silent" face of gp120 (7-10). Crystal structures of 2G12 Fab alone, and in complex with oligosaccharides Man 9 GlcNAc 2 and Manα1-2Man, revealed that two Fab monomers assemble into an interlocked, domain-swapped dimer, that forms an extensive, multivalent binding surface (11). Four Man 9 GlcNAc 2 moieties were observed bound to the Fab dimer in the crystal structure, occupying the two canonical antigen-binding sites, and two novel ones located at the assembled interface of the two interlocked V H domains. Since the identification of its epitope, MAb 2G12 has received significant attention as a template for HIV-1 vaccine development. Considerable effort has been directed at characterizing its oligosaccharide-binding profile (12)(13)(14)(15), and the generation of novel antigens in the form of synthetic oligomannoses (13,16,17) or short, synthetic glycopeptides (18-20). In an attempt to generate immunogens that elicit 2G12-like antibodies, we chose to isolate peptides t...

show abstract

“…Ligand protons that participate in protein binding are subsequently detected and identified with high sensitivity. STD has been successfully applied to identify binding epitopes in multiple systems including peptide/protein, polysaccharide/protein, small molecule/protein and RNA/ small molecule (Johnson et al, 2003;Mayer and James, 2002;Mayer and Meyer, 2001;Pons et al, 2008).…”

Section: Introductionmentioning

confidence: 99%

Mechanistic studies of displacer–protein binding in chemically selective displacement systems using NMR and MD simulations

Morrison¹,

Godawat²,

McCallum³

et al. 2008

Biotech & Bioengineering

View full text Add to dashboard Cite

A parallel batch screening technique was employed to identify chemically selective displacers which exhibited exclusive separation behavior for the protein pair a-chymotrypsin/ribonuclease A on a strong cation exchange resin. Two selective displacers, 1-(4-chlorobenzyl)piperidin-3-aminesulfate and N 0 1 0 -(4-methyl-quinolin-2-yl)-ethane-1,2-diamine dinitrate, and one non-selective displacer, spermidine, were selected as model systems to investigate the mechanism of chemically selective displacement chromatography. Saturation transfer difference (STD) NMR was used to directly evaluate displacer-protein binding. The results indicated that while binding occurred between the two chemically selective displacers and the more hydrophobic protein, a-chymotrypsin, no binding was observed with ribonuclease A. Further, the non-selective displacer, spermidine, was not observed to bind to either protein. Importantly, the binding event was observed to occur primarily on the aromatic portion of the selective displacers. Extensive molecular dynamic simulations of protein-displacer-water solution were also carried out. The MD results corroborated the NMR findings demonstrating that the binding of selective displacers occurred primarily on hydrophobic surface patches of a-chymotrypsin, while no significant long term binding to ribonuclease A was observed. The non-selective displacer did not show significant binding to either of the proteins. MD simulations also indicated that the charged amine group of the selective displacers in the bound state was primarily oriented towards the solvent, potentially facilitating their interaction with a resin surface. These results directly confirm that selective binding between a protein and displacer is the mechanism by which chemically selective displacement occurs. This opens up many possibilities for future molecular design of selective displacers for a range of applications.

show abstract

NMR Studies of Carbohydrates and Carbohydrate-mimetic Peptides Recognized by an Anti-Group B Streptococcus Antibody

Cited by 28 publications

References 49 publications

Toward a Better Understanding of the Basis of the Molecular Mimicry of Polysaccharide Antigens by Peptides

Toward a Better Understanding of the Basis of the Molecular Mimicry of Polysaccharide Antigens by Peptides

A peptide inhibitor of HIV‐1 neutralizing antibody 2G12 is not a structural mimic of the natural carbohydrate epitope on gp120

Mechanistic studies of displacer–protein binding in chemically selective displacement systems using NMR and MD simulations

Contact Info

Product

Resources

About