N-acetyl-D-galactosamine 6-sulfate (GalNAc6S) (GalNAc6S)

N-acetyl-D-galactosamine 6-sulfate (GalNAc6S) is a specific sulfated sugar residue found within the polysaccharide chains of chondroitin-6-sulfate and keratan sulfate. These glycosaminoglycans are vital components of the extracellular matrix, particularly in cartilage, heart valves, and the cornea, where they contribute to structural integrity and cellular signaling (Source: PubMed, PMID: 24533101). Under normal physiological conditions, the enzyme N-acetylgalactosamine-6-sulfatase (GALNS) cleaves the sulfate group from this residue during the degradation of these large molecules. In patients with Mucopolysaccharidosis IVA, also known as Morquio A syndrome, a deficiency in GALNS leads to the systemic accumulation of GalNAc6S-containing glycosaminoglycans within lysosomes (Source: NIH, GARD). This accumulation causes progressive skeletal dysplasia, joint instability, and potential respiratory or cardiovascular complications. Therapeutic intervention involves enzyme replacement therapy with elosulfase alfa, a recombinant form of human GALNS that targets these accumulated residues to facilitate their breakdown and clearance (Source: FDA, Vimizim Prescribing Information).

Other names

GalNAc6SN-acetylgalactosamine-6-sulfateChondroitin-6-sulfate residueChondroitin sulfate C residue

Enzymatic hydrolysis of the sulfate ester bond at the C6 position of the N-acetylgalactosamine residue