A heme-thiolate protein (P-450). Enzymes of this type include glycoproteins secreted by agaric basidiomycetes. They catalyse the insertion of an oxygen atom from H2O2 into a wide variety of substrates, including aromatic rings such as naphthalene, toluene, phenanthrene, pyrene and p-nitrophenol, recalcitrant heterocycles such as pyridine, dibenzofuran, various ethers (resulting in O-dealkylation) and alkanes such as propane, hexane and cyclohexane. Reactions catalysed include hydroxylation, epoxidation, N-oxidation, sulfooxidation, O- and N-dealkylation, bromination and one-electron oxidations. They have little or no activity toward chloride. Mechanistically, the catalytic cycle of unspecific (mono)-peroxygenases combines elements of the "shunt" pathway of cytochrome P-450s (a side activity that utilizes a peroxide in place of dioxygen and NAD[P]H) and the classic heme peroxidase cycle.