In enzymology, a glucuronan lyase (EC22.214.171.124) is an enzyme that catalyzes the chemical reaction of eliminative cleavage of (1->4)-beta-D-glucuronans. This produces either oligosaccharides with 4-deoxy-beta-D-gluc-4-enuronosyl groups at their non-reducing ends, or, if the substrate is completely degraded, glucuronans produce tetrasaccharides.
This enzyme belongs to the family of lyases, specifically those carbon-oxygen lyases acting on polysaccharides. The systematic name of this enzyme class is (1->4)-beta-D-glucuronan lyase. This enzyme is also called (1,4)-beta-D-glucuronan lyase.