In enzymology, a bilirubin oxidase, BOD or BOx, (EC 1.3.3.5) is an enzyme encoded by a gene in various organisms that catalyzes the chemical reaction This enzyme belongs to the family of oxidoreductases, to be specific those acting on the CH-CH group of donor with oxygen as acceptor.

[1] Two structures of bilirubin oxidase from the ascomycete Myrothecium verrucaria have been deposited in the Protein Data Bank (accession codes 3abg and 2xll).

[2][3] The active site consists of four copper centers, reminiscent of laccase.

[4] The latter two centers are arranged in a trinuclear copper cluster forming the active site for oxygen reduction.

[5] The type I copper center is the primary electron acceptor and the site for the reduction of bilirubin.