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Antibody Recognition in multiple sclerosis and rett syndrome using a collection of linear and cyclic N ‐glucosylated antigenic probes
Author(s) -
Real Fernández Feliciana,
Di Pisa Margherita,
Rossi Giada,
Auberger Nicolas,
Lequin Olivier,
Larregola Maud,
Benchohra Amina,
Mansuy Christelle,
Chassaing Gerard,
Lolli Francesco,
Hayek Joussef,
Lavielle Solange,
Rovero Paolo,
Mallet JeanMaurice,
Papini Anna Maria
Publication year - 2015
Publication title -
peptide science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.556
H-Index - 125
eISSN - 1097-0282
pISSN - 0006-3525
DOI - 10.1002/bip.22677
Subject(s) - chemistry , antibody , peptide , antigen , surface plasmon resonance , ic50 , immunoglobulin light chain , microbiology and biotechnology , biochemistry , in vitro , immunology , biology , materials science , nanoparticle , nanotechnology
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 IC 50 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‐NH 2 , with an IC 50 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‐NH 2 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‐NH 2 to favor immobilization on SPR sensor chips. SPR technology allowed us to determine its affinity (K D = 16.4 nM), 2.3 times lower than the affinity of the original glucopeptide CSF114(Glc) (K D = 7.1 nM). © 2015 Wiley Periodicals, Inc. Biopolymers (Pept Sci) 104: 560–576, 2015.