Reaction: HEXA cleaves the terminal GalNAc from small HA fragments
- in pathway: Hyaluronan uptake and degradation
Beta-hexosaminidase (HEX) cleaves the terminal N-acetyl galactosamine (GalNAc) from glucosaminoglycans (GAGs) and any other molecules containing a terminal GalNAc. There are two forms of HEX; HEXA and B. The A form is a trimer of the subunits alpha, beta A and beta B. The B form is a tetramer of 2 beta A and 2 beta B subunits (O'Dowd et al. 1988). Defects in the two subunits cause lysosomal storage diseases marked by the accumulation of GM2 gangliosides in neuronal cells.
Reaction - small molecule participants:
GlcNAc [lysosomal lumen]
GlcA-β1,3-GlcNAc [lysosomal lumen]
H2O [lysosomal lumen]
Reactome.org reaction link: R-HSA-2162225
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Reaction input - small molecules:
water
Reaction output - small molecules:
aldehydo-N-acetyl-D-glucosamine
beta-D-GlcpA-(1->3)-D-GlcpNAc
Reactome.org link: R-HSA-2162225