Reactome | GLCE epimerises GlcA to IdoA

GLCE epimerises GlcA to IdoA

Stable Identifier

R-HSA-2024100

Type

Reaction [transition]

Species

Homo sapiens

Compartment

Golgi membrane, Golgi lumen

ReviewStatus

5/5

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As the sulfate content rises, so does the iduronic acid:glucuronic acid ratio. Once glucosamine is sulfated, glucuronic acid (GlcA) is epimerised to iduronic acid (IdoA). The enzyme glucuronyl C5-epimerase (GLCE) mediates this reaction, evidence of function and cellular location coming from mouse studies (Li et al. 2001, Crawford et al. 2001). The distinction between HS and heparin is fairly arbritary but generally, low-sulfated and GlcA-rich polysaccharides are called HS and high-sulfated and IdoA-rich polysaccharides are called heparin. It can be argued that this structure can now be called either heparan sulfate-PG or heparin-PG.

Literature References

PubMed ID	Title	Journal	Year
11274177	Characterization of the D-glucuronyl C5-epimerase involved in the biosynthesis of heparin and heparan sulfate Li, JP, Gong, F, Jalkanen, M, Lindahl, U, El Darwish, K	J Biol Chem	2001
11279150	Cloning, Golgi localization, and enzyme activity of the full-length heparin/heparan sulfate-glucuronic acid C5-epimerase Crawford, BE, Pinhal, MA, Esko, JD, Olson, SK	J Biol Chem	2001