Human proinsulin, the single-chain peptide precursor of insulin, consists of the insulin A and B chains connected by the 31 amino acid C-peptide. Cleavage of proinsulin by proteolytic enzymes produces insulin and free C-peptide.
MOG (35-55), human, a constituent of central nervous system myelin, is distinguishable from mMOG (35-55) due to a proline-to-serine substitution at position 42. It possesses immunogenic properties and is partially cross-reactive with mMOG35–55. However, MOG (35-55), human does not induce encephalitogenic effects, and only elicits minimal clinical signs of EAE (experimental autoimmune encephalomyelitis) in comparison to the rodent peptide.