Involved in the formation of a rigid and insoluble egg chorion by catalyzing chorion protein cross-linking through dityrosine formation and phenol oxidase-catalyzed chorion melanization. 2 a phenolic donor + H2O2 = 2 a phenolic radical donor + 2 H2O Binds 1 heme b (iron(II)-protoporphyrin IX) group per heterodimer. Extremely resistant to denaturating agents, such as SDS and organic solvents. Optimum pH is 8.0 with guaiacol as the reducing agent. Heterodimer. In the chorion layer of the mature eggs. Expression levels increase 24 hours following blood feeding. Peak peroxidase activity is reached at 36-48 hours after a blood-meal. N-glycosylated on Trp by mannose and on Asn by N-acetylglucosamine. There is a hexose glycosylation of an unidentified residue between 654 and 708; Trp-680 is conserved in closely related species and is probably mannosylated. Belongs to the peroxidase family. XPO subfamily. Extended N-terminus.