IgG and IgM antibodies to the refolded MOG1-125 extracellular domain in humans

Antibodies to MOG in serum have a dubious prognostic value in multiple sclerosis. The MOG recombinant protein conformational properties relevant to the antigenic activity are unknown. We employed a solid-phase ELISA based on a product (rMOGED(His)6) expressed in E. coli after subcloning the cDNA of the extracellular domain of rat MOG, performing a refolding procedure on column and affinity purification. The far-UV Circular Dichroism (CD) spectra of rMOGED(His)6 showed a β-sheet, a characteristic feature of the Ig-fold. However, in MS sera and controls we failed to detected IgM or IgG antibodies.