Mannosylated Linear and Cyclic Single Amino Acid Mutant Peptides Using a Small 10 Amino Acid Linker Constitute Promising Candidates Against Multiple Sclerosis

Abstract

Multiple sclerosis (MS) is a serious autoimmune demyelinating disease leading to loss of neurological function. The design and synthesis of various altered peptide ligands of immunodominant epitopes of myelin proteins to alter the autoimmune response, is a promising therapeutic approach for MS. In this study, linear and cyclic peptide analogs based on the myelin basic protein 83–99 (MBP83–99) immunodominant epitope conjugated to reduced mannan via the (KG)5 and keyhole limpet hemocyanin (KLH) bridge, respectively, were evaluated for their biological/immunological profiles in SJL/J mice. Of all the peptide analogs tested, linear MBP83–99(F91) and linear MBP83–99(Y91) conjugated to reduced mannan via a (KG)5 linker and cyclic MBP83–99(F91) conjugated to reduce mannan via KLH linker, yielded the best immunological profile and constitute novel candidates for further immunotherapeutic studies against MS in animal models and in human clinical trials.

Myelin-derived and putative molecular mimic peptides share structural properties in aqueous and membrane-like environments

“…All our experiments point towards highly similar properties for all the studied peptides. In this respect, it is of interest to note the possible potential of myelin protein-derived peptides in MS therapy; these include both cyclic and mutated variants of myelin antigen peptides, especially MBP85-99 [59,[94][95][96][97][98]; the design of such peptides could also take into account our observations on similar overall structural and membrane interaction properties of peptides with limited sequence similarity per se. While the link between membrane binding, membraneinduced folding, and autoimmune response is unclear, molecular mimicry possibly taking place in autoimmune demyelination may be based on 3D similarity of host and pathogen epitopes.…”

“…Nine peptides from four human or mouse compact myelin proteins with a putative autoimmunogenic character and four viral/bacterial peptides suggested [19] to mimic the well-known MS-associated MBP sequence (amino acids [85][86][87][88][89][90][91][92][93][94][95][96][97][98][99] were chosen for structural analysis; all peptides have been described in the literature earlier (see Table 1 and references therein). The corresponding MBP85-99 peptide was a subject of our earlier study [31].…”

Conjugation of a peptide to mannan and its confirmation by tricine sodium dodecyl sulfate–polyacrylamide gel electrophoresis

“…Of particular interest for the scientific community and health services are the peptides from myelin proteins conjugated to oxidized or reduced mannan which are potentially pathogenic in multiple sclerosis [5][6][7]. Although the synthesis and the promising in vitro and in vivo efficacy of these molecules has been described [5][6][7], the extent of conjugation and the redox condition of the participating sugars is not routinely assessed by a simple, low cost and efficient analytical method. Capilary Electrophoresis (CE) however, was used previously by our group for the detection and confirmation of conjugation between a cyclic peptide and oxidized mannan.…”

“…4 staining has been used for the electrophoretic analysis of proteins with molecular weights below 30 kDa [9]. In this study tricine SDS-PAGE and Coomassie Blue stain [10] were used to confirm the conjugation MOG 35-55 to mannan via (LysGly) 5 linker, and tricine SDS-PAGE followed by Periodic acid-Schiff stain (PAS) [11] and 2,4-dinitrophenylhydrazine (DNP) colorimetric assay [12] to evaluate the presence of aldehydes in the redox state of the mannan moiety.…”

“…Unreacted aldehydes and remaining Schiff bases in the oxidized mannanpeptide conjugate were reduced to alcohols and amines respectively by sodium borohydride (0.025 mM NaBH 4 , 3 h at room temperature) ( Fig. 1) [4][5][6].…”