coproporphyrinogen

See porphyrinogens.

- c. oxidase an enzyme that catalyzes a step in porphyrin biosynthesis, reacting c. III and O₂ to form protoporphyrinogen IX and 2CO₂. A deficiency of this enzyme will result in hereditary coproporphyria.

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cop·ro·por·phy·rin·o·gen (kop″ro-por″fə-rinґo-jən) a porphyrinogen (q.v.) in which each pyrrole ring has one methyl side chain and one propionate side chain; it is formed by oxidative decarboxylation of uroporphyrinogen. Four isomers are possible but only two exist naturally, types I and III; the latter is a functional intermediate in heme biosynthesis while the former is produced in an abortive side reaction.