The enzyme carboxymethyloxysuccinate lyase (EC 4.2.99.12) catalyzes the chemical reaction

carboxymethyloxysuccinate ${\displaystyle \rightleftharpoons }$ fumarate + glycolate

This enzyme belongs to the family of lyases, specifically the "catch-all" class of lyases that cleave carbon-oxygen bonds. The systematic name of this enzyme class is carboxymethyloxysuccinate glycolate-lyase (fumarate-forming). Other names in common use include carbon-oxygen lyase, and carboxymethyloxysuccinate glycolate-lyase.

• Peterson D, Llaneza J (1974). "Identification of a carbon-oxygen lyase activity cleaving the ether linkage in carboxymethyloxysuccinic acid". Arch. Biochem. Biophys. 162 (1): 135–46. doi:10.1016/0003-9861(74)90112-X. PMID 4831330.