Conformational structure of the MOG-derived peptide 101-108 in solution

One of the most important targets in the autoimmune attack in experimental autoimmune encephalomyielitis is the myelin oligodendrocyte glycoprotein (MOG). The complex with demyelinating 8-18C5 antibody was recently resolved by X-ray crystallography, showing a remarkable adhesion of the 101-108 MOG subsequence to the heavy chain of the autoantibody. In this study, we have determined, using replica exchange molecular dynamics methods, the structure of the MOG-derived peptide 101-108 in solution at ambient conditions. According to the simulation, the peptide exhibits, with significant probability, a distorted beta-turn structure highly similar to that of the corresponding subsequence in the crystal in complex with 8-18C5 antibody. Such results are found to be fully consistent with circular dichroism spectra of the peptide in solution, suggesting the use of the MOG-derived 101-108 peptide as a potential lead compound for designing decoy targets for the autoimmune attack in multiple sclerosis.