Unspecific peroxygenases (UPOs) represent an emerging class of catalysts for the selective oxyfunctionalisation of C–H- and C = C groups. Until now, only a few UPOs have been characterised. In this study, we report a new peroxygenase identified from the Unspecific Peroxygenase Database. The UPO from Agaricus bisporus var. bisporus (AbvbUPO) has been heterologously expressed in Aspergillus niger and initially characterised with respect to its basic biochemical features. Furthermore, its catalytic properties were evaluated with enzymatic cascade reactions of choline oxidase (AnChOx) and AbvbUPO, which the AnChOx provided H₂O₂ necessary via reductive activation of oxygen in situ. Three types of oxyfunctionalizations, such as hydroxylation of ethylbenzene, epoxidations of styrene and cyclohexene, sulfoxidations of methyl phenyl sulfide and phenyl vinyl sulfide, were successfully achieved. We also investigated the activity of AbvbUPO on fatty acids in some more detail. The experimental results show that Under the above conditions, AbvbUPO had the higher activity for cyclohexene epoxidation and sulfonation of sulfide substrates. The concentration of epoxy cyclohexane was 2.91 mM, and the concentration of methyl phenyl sulfoxide was 3.69 mM. The regioselectivity of AbvbUPO was ω-1 bonds position of linear saturated fatty acid. All in all, AbvbUPO exhibits some interesting differences which may put the basis for further understanding of the factors determining peroxygenase selectivity.

Unspecific peroxygenases (UPOs, EC 1.11.2.1) are promising oxyfunctionalization catalysts because of their unique stereoselectivity. However, so far only a few UPOs have been reported. In this study, gene mining was used to identify a gene from Galerina marginata that coded for a novel UPO (GmaUPO). GmaUPO was expressed in Pichia pastoris X-33 by scale-up fermentation (the UPO activity of the culture supernatant was 118 U/L). GmaUPO exhibited a molecular weight of 40 kDa and exhibited highest activity at 35°C and pH 9, respectively. Furthermore, GmaUPO was demonstrated to catalyze the epoxidation, sulfoxidation, and hydroxylation of common substrates, particularly fatty acids such as tridecanoic acid. The molecular basis for GmaUPO regioselectivity for fatty acid hydroxylation was explored by molecular modelling. The regioselectivity was mostly governed by the architecture of the enzyme's active site.