Institute of
bioorganic chemistry

Human biosynthetic machinery only synthesizes N-acetylneuraminic acid (Neu5Ac), while the other mammals synthesize both it and N-glycolylneuraminic acid (Neu5Gc), i.e., the latter is a potential xeno-antigen for humans. At the same time, Neu5Ac from the eaten meat of animals is metabolically active and found in human glycans, so it was believed that humans have antibodies to Neu5Gca2-3Galb1-4GlcNAc. Researchers from the Laboratory of Carbohydrates IBCH RAS systematically studied the repertoire of antibodies from healthy donors and found (see Glycobiology) that they have practically no antibodies to this glycan. At the same time, antibodies to Neu5Gc-containing glycans were found in patients with multiple sclerosis (see Neurology: Neuroimmunology & Neuroinflammation), which may be a marker of this disease.