title: Antibody recognition in multiple sclerosis and Rett syndrome using a collection of linear and cyclic N-glucosylated antigenic probes.
abstract: Antibody detection in autoimmune disorders, such as multiple sclerosis (MS) and Rett syndrome (RTT) can be achieved more efficiently using synthetic peptides. The previously developed synthetic antigenic probe CSF114(Glc), a type I' β-turn N-glucosylated peptide structure, is able to recognize antibodies in MS and RTT patients' sera as a sign of immune system derangement. We report herein the design, synthesis, conformational analysis, and immunological evaluation of a collection of glycopeptide analogs of CSF114(Glc) to characterize the specific role of secondary structures in MS and RTT antibody recognition. Therefore, we synthesized a series of linear and cyclic short glucosylated sequences, mimicking different β-turn conformations, which were evaluated in inhibition enzyme-linked immunosorbent assays (ELISA). Calculated IC50 ranking analysis allowed the selection of the candidate octapeptide containing two (S)-2-amino-4-pentynoic acid (L-Pra) residues Ac-Pra-RRN(Glc)GHT-Pra-NH2 , with an IC50 in the nanomolar range. This peptide was adequately modified for solid-phase ELISA (SP-ELISA) and surface plasmon resonance (SPR) experiments. Pra-RRN(Glc)GHT-Pra-NH2 peptide was modified with an alkyl chain linked to the N-terminus, favoring immobilization on solid phase in SP-ELISA and differentiating IgG antibody recognition between patients and healthy blood donors with a high specificity. However, this peptide displayed a loss in IgM specificity and sensitivity. Moreover, an analog was obtained after modification of the octapeptide candidate Ac-Pra-RRN(Glc)GHT-Pra-NH2 to favor immobilization on SPR sensor chips. SPR technology allowed us to determine its affinity (KD  = 16.4 nM), 2.3 times lower than the affinity of the original glucopeptide CSF114(Glc) (KD  = 7.1 nM).
authors.affiliation: French-Italian Interdepartmental Laboratory of Peptide and Protein Chemistry and Biology, PeptLab (http://www.peptlab.eu).|Department of Neurosciences, Psychology, Drug Research and Child Health, Section of Pharmaceutical Sciences and Nutraceutics, University of Florence, Via Ugo Schiff 6, 50019 Sesto Fiorentino, Italy.
authors.forename: Feliciana
authors.initials: F
authors.lastname: Real Fernández
authors.affiliation: Département de Chimie, École Normale Supérieure-PSL Research University, 24 rue Lhomond, Sorbonne Universités, UPMC Univ Paris 06, LBM, 4 place Jussieu, CNRS, UMR 7203 LBM, 75005, Paris, France.
authors.forename: Margherita
authors.initials: M
authors.lastname: Di Pisa
authors.affiliation: French-Italian Interdepartmental Laboratory of Peptide and Protein Chemistry and Biology, PeptLab (http://www.peptlab.eu).|Department of Neurosciences, Psychology, Drug Research and Child Health, Section of Pharmaceutical Sciences and Nutraceutics, University of Florence, Via Ugo Schiff 6, 50019 Sesto Fiorentino, Italy.
authors.forename: Giada
authors.initials: G
authors.lastname: Rossi
authors.affiliation: Département de Chimie, École Normale Supérieure-PSL Research University, 24 rue Lhomond, Sorbonne Universités, UPMC Univ Paris 06, LBM, 4 place Jussieu, CNRS, UMR 7203 LBM, 75005, Paris, France.
authors.forename: Nicolas
authors.initials: N
authors.lastname: Auberger
authors.affiliation: Département de Chimie, École Normale Supérieure-PSL Research University, 24 rue Lhomond, Sorbonne Universités, UPMC Univ Paris 06, LBM, 4 place Jussieu, CNRS, UMR 7203 LBM, 75005, Paris, France.
authors.forename: Olivier
authors.initials: O
authors.lastname: Lequin
authors.affiliation: French-Italian Interdepartmental Laboratory of Peptide and Protein Chemistry and Biology, PeptLab (http://www.peptlab.eu).|PeptLab@UCP Platform and Laboratory of Chemical Biology EA4505, University of Cergy-Pontoise, 5 Mail Gay Lussac, 95031, Cergy-Pontoise Cedex, France.
authors.forename: Maud
authors.initials: M
authors.lastname: Larregola
authors.affiliation: French-Italian Interdepartmental Laboratory of Peptide and Protein Chemistry and Biology, PeptLab (http://www.peptlab.eu).|Department of Chemistry 'Ugo Schiff', University of Florence, Via della Lastruccia 13, 50019, Sesto Fiorentino, Italy.
authors.forename: Amina
authors.initials: A
authors.lastname: Benchohra
authors.affiliation: Département de Chimie, École Normale Supérieure-PSL Research University, 24 rue Lhomond, Sorbonne Universités, UPMC Univ Paris 06, LBM, 4 place Jussieu, CNRS, UMR 7203 LBM, 75005, Paris, France.
authors.forename: Christelle
authors.initials: C
authors.lastname: Mansuy
authors.affiliation: Département de Chimie, École Normale Supérieure-PSL Research University, 24 rue Lhomond, Sorbonne Universités, UPMC Univ Paris 06, LBM, 4 place Jussieu, CNRS, UMR 7203 LBM, 75005, Paris, France.
authors.forename: Gerard
authors.initials: G
authors.lastname: Chassaing
authors.affiliation: French-Italian Interdepartmental Laboratory of Peptide and Protein Chemistry and Biology, PeptLab (http://www.peptlab.eu).|Dipartimento di Scienze Biomediche Sperimentali e Cliniche, University of Florence, Viale Morgagni 50, 50134, Firenze, Italy.
authors.forename: Francesco
authors.initials: F
authors.lastname: Lolli
authors.affiliation: Child Neuropsychiatry Unit, Azienda Ospedaliera Universitaria Senese (AOUS), 53100, Siena, Italy.
authors.forename: Joussef
authors.initials: J
authors.lastname: Hayek
authors.affiliation: Département de Chimie, École Normale Supérieure-PSL Research University, 24 rue Lhomond, Sorbonne Universités, UPMC Univ Paris 06, LBM, 4 place Jussieu, CNRS, UMR 7203 LBM, 75005, Paris, France.
authors.forename: Solange
authors.initials: S
authors.lastname: Lavielle
authors.affiliation: French-Italian Interdepartmental Laboratory of Peptide and Protein Chemistry and Biology, PeptLab (http://www.peptlab.eu).|Department of Neurosciences, Psychology, Drug Research and Child Health, Section of Pharmaceutical Sciences and Nutraceutics, University of Florence, Via Ugo Schiff 6, 50019 Sesto Fiorentino, Italy.
authors.forename: Paolo
authors.initials: P
authors.lastname: Rovero
authors.affiliation: Département de Chimie, École Normale Supérieure-PSL Research University, 24 rue Lhomond, Sorbonne Universités, UPMC Univ Paris 06, LBM, 4 place Jussieu, CNRS, UMR 7203 LBM, 75005, Paris, France.
authors.forename: Jean-Maurice
authors.initials: JM
authors.lastname: Mallet
authors.affiliation: French-Italian Interdepartmental Laboratory of Peptide and Protein Chemistry and Biology, PeptLab (http://www.peptlab.eu).|PeptLab@UCP Platform and Laboratory of Chemical Biology EA4505, University of Cergy-Pontoise, 5 Mail Gay Lussac, 95031, Cergy-Pontoise Cedex, France.|Department of Chemistry 'Ugo Schiff', University of Florence, Via della Lastruccia 13, 50019, Sesto Fiorentino, Italy.
authors.forename: Anna Maria
authors.initials: AM
authors.lastname: Papini
mesh_terms: D000918:Antibody Specificity; D004797:Enzyme-Linked Immunosorbent Assay; D006001:Glycoconjugates / Q000737:chemistry*; D006801:Humans; D020128:Inhibitory Concentration 50; D009103:Multiple Sclerosis / Q000276:immunology*; D011487:Protein Conformation; D015518:Rett Syndrome / Q000276:immunology*
chemical_list: D006001:Glycoconjugates
keywords: antibody affinity; antibody recognition; structural-activity relationship; surface plasmon resonance; synthetic antigenic probes