N-acetylgalactosamine-4-sulfatase (ARSB) (ARSB)

N-acetylgalactosamine-4-sulfatase (ARSB), also known as Arylsulfatase B, is a critical lysosomal enzyme involved in the stepwise degradation of glycosaminoglycans (GAGs), specifically dermatan sulfate and chondroitin 4-sulfate (UniProt: P15848). It functions by removing the sulfate group from the C4 position of N-acetylgalactosamine residues. A genetic deficiency in ARSB leads to Mucopolysaccharidosis VI (MPS VI), a lysosomal storage disorder characterized by the pathological accumulation of GAGs in various tissues, leading to skeletal abnormalities, impaired vision, and cardiovascular issues (NIH: GARD). The primary therapeutic approach is enzyme replacement therapy using Galsulfase, a recombinant form of the human enzyme, which is internalized by cells and trafficked to lysosomes to restore degradative function (DrugBank: DB01279). Clinical management focuses on reducing substrate levels, often monitored via urinary GAG excretion, to alleviate systemic symptoms and slow disease progression (PubMed: PMID 16730554). Treatment requires lifelong administration and careful monitoring for infusion-related reactions.

Other names

Arylsulfatase BASBChondroitinsulfataseGalsulfaseN-acetylgalactosamine-4-sulfate sulfohydrolase

Enzyme replacement therapy (ERT) provides an exogenous source of the functional enzyme to catalyze the degradation of accumulated glycosaminoglycans within lysosomes.