Tetrahydroberberine oxidase
'-Tetrahydroberberine oxidase is an enzyme that catalyzes the final transformation in the biosynthesis of berberine, a quaternary benzylisoquinoline alkaloid of the protoberberine structural subgroup. This reaction pathway catalyzes the four-electron oxidation of -tetrahydroberberine in the presence of oxygen to produce berberine and hydrogen peroxide.
This enzyme belongs to the family known as oxidoreductases, in this instance the CH-CH moiety acts as the electron donor with oxygen acting as the electron acceptor. The systematic name of this enzyme is '-tetrahydroberberine:oxygen oxidoreductase; but it is also known as '-THB oxidase, tetrahydroberberine oxidase, and decreasingly, as '-tetrahydroprotoberberine oxidase.