Unspecific peroxygenase (UPO) represents a new type of heme-thiolate enzyme with self-
sufficient mono (per) oxygenase activity and many potential applications in organic
synthesis. With a view to taking advantage of these properties, we subjected the Agrocybe
aegerita UPO1-encoding gene to directed evolution in Saccharomyces cerevisiae. To
promote functional expression, several different signal peptides were fused to the mature
protein, and the resulting products were tested. Over 9,000 clones were screened using an …

Unspecific peroxygenase (UPO) is a heme-thiolate peroxidase with mono (per) oxygenase
activity for the selective oxyfunctionalization of CH bonds. Fueled by catalytic concentrations
of H 2 O 2, which acts as both oxygen donor and as final electron acceptor, this stable,
soluble, and extracellular enzyme is a potential biocatalyst for dozens of transformations that
are of considerable interest in organic synthesis. In this chapter we describe the main
attributes of this versatile enzyme while reflecting on the directed evolution campaigns …