Biochemistry · Molecule
GM2 ganglioside !
GM2 ganglioside is a sialic acid-containing glycolipid of neuronal membranes. It builds up in neurons in Tay–Sachs disease.
Updated 2026-11-01
Key facts
- Ceramide + glucose + galactose + N-acetylgalactosamine, with one sialic acid (N-acetylneuraminic acid) on the galactose.
- "G" = ganglioside, "M" = one (mono) sialic acid, "2" = its chromatography migration order.
- Hexosaminidase A (αβ) removes the terminal N-acetylgalactosamine, turning it into GM3; it needs the GM2 activator protein.
- It fails in Tay–Sachs (α subunit, HEXA), Sandhoff (β subunit, HEXB) and the AB variant (activator, GM2A).
- Also called
- GM2, Tay–Sachs ganglioside
- Formula
- C₆₈H₁₂₃N₃O₂₆
Structure
- PubChem (CID 71308211) offers no 3D model because of its size and flexibility, and there is no PDB chemical component for the whole ganglioside; this page has no 3D.
- A four-sugar head with a negative charge (sialic acid) on two ceramide tails that sink into the bilayer.
Clinical notes
- In Tay–Sachs, neurons swell with GM2 (membranous cytoplasmic bodies): regression, seizures, blindness and a cherry-red spot.
- In Sandhoff disease globoside also accumulates in organs, so hepatosplenomegaly may appear.
Pathways
Related conditions
Related
- Hexosaminidase A (β-hexosaminidase A)
- Sphingolipids and sphingolipidoses
- Ceramide
- Glucosylceramide (glucocerebroside)
Test yourself
Think of the answer, then tap the question to see it.
Which sugar does hexosaminidase A remove from GM2 ganglioside?
The terminal N-acetylgalactosamine; the product is GM3 ganglioside.
What do the letters and number in "GM2" mean?
G = ganglioside, M = a single sialic acid, 2 = its chromatographic migration order.
Which three genetic defects store GM2?
HEXA (Tay–Sachs), HEXB (Sandhoff) and GM2A (AB variant, missing activator).
Educational information, not medical advice. For any symptom, see a health professional.
Sources: Ganglioside GM2 (CID 71308211) (PubChem, NCBI, 2026) · Public domain; Glycosphingolipid metabolism (Reactome, 2026); HEXA gene: MedlinePlus Genetics (MedlinePlus, US National Library of Medicine, 2026); Textbook of Biochemistry for Medical Students, 6th ed. (Jaypee Brothers Medical Publishers (Vasudevan DM, Sreekumari S, Vaidyanathan K), 2011).
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Representative model, for educational purposes only.