Reaction: Defective HYAL1 does not hydrolyse (HA)50
- in pathway: MPS IX - Natowicz syndrome
In the acidic environment of the lysosome, hyaluronidase 1 (HYAL1) is able to hydrolyse large 20kDa HA fragments (approximately 50 disaccharide units) to 800 Da fragments (2 disaccharide units). Defects in HYAL1 (MIM:607071) cause mucopolysaccharidosis type IX (MPS IX, Natowicz syndrome, Hyaluronidase deficiency, MIM:601492), a rare lysosomal storage disease. Triggs-Raine et al. identified a patient with two mutations in HYAL1 alleles, a nonconservative amino acid substitution (Glu268Lys, that is HYAL1 E268K) and a complex intragenic rearrangement (1361del37ins14, that is HYAL1 V251Ffs*20) that results in a premature termination codon (Triggs-Raine et al. 1999).
Reaction - small molecule participants:
H2O [lysosomal lumen]
Reactome.org reaction link: R-HSA-9036077
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Reaction input - small molecules:
water
Reaction output - small molecules:
Reactome.org link: R-HSA-9036077