Enhanced secretion of an Agrocybe aegerita peroxygenase variant in K. phaffii using the native signal peptide.
Peptide researchers looking to boost enzyme yields just got a new data point. A team from the University of York showed that using the native signal peptide from the fungus Agrocybe aegerita cranked up secretion of its popular peroxygenase (UPO) variant in Komagataella phaffii yeast—by a factor of five to seven. Forget the usual tweaks. In this case, sticking with the original works better than the engineered alternatives.
AMB Express
by Camboni G, Preece R, Cornish KAS et al.
“Enhanced secretion of an Agrocybe aegerita peroxygenase variant in K. phaffii using the native signal peptide. Camboni G(1)(2), Preece R(2), Cornish KAS(1)(2), Cartwright J(3), Grogan G(4). Author information: (1)Departments of Chemistry, University of York, Heslington, YO10 5DD, York, United Kingdom. (2)Departments of Biology, University of York, Heslington, York, YO10 5DD, United Kingdom. (3)Departments of Biology, University of York, Heslington, York, YO10 5DD, United Kingdom. jared.cartwright@york.ac.uk. (4)Departments of Chemistry, University of York, Heslington, YO10 5DD, York, United Kingdom. gideon.grogan@york.ac.uk. Unspecific Peroxygenases (UPOs) are enzymes with significant potential as catalysts in synthetic chemistry as they catalyse selective oxygenation reactions on organic substrates at the expense of only hydrogen peroxide as the external oxidant. The demand for UPOs has stimulated considerable research into efficient heterologous expression systems for their production, which have included optimisation of the signal peptide (SP) included upstream of the UPO gene. In this study we report a comparison of the production of the prototypical and widely-used UPO variant from the fungus Agrocybe aegerita (rAaeUPO-PaDa-I-H) using both its native SP and variant SPs evolved for improved heterologous expression in yeast hosts. The results show that improvements in protein production identified using variant SPs in S. cerevisiae are not necessarily extended to the yeast Komagataella phaffii. Indeed in K. phaffii we observed a five to sevenfold improvement in the activity of crude secretates produced using the native fungal SP of AaeUPO, compared with SPs that were evolved for improved expression and screened in S. cerevisiae These findings suggest that superior yields of this widely-used UPO can be obtained from scaled production in K. phaffii by using the native SP from the source fungus. © 2026. The Author(s). Conflict of interest statement: Declarations. Ethics approval and consent to participate: This article does not include and research conducted on human subjects by the authors. Consent for publication: Not applicable. Competing interests: The authors declare no competing interests.”
Here’s the setup: Unspecific peroxygenases (UPOs) are a favorite tool in synthetic chemistry. They pull off tricky oxygenation reactions with just hydrogen peroxide. But making enough of these enzymes means expressing them efficiently in a host organism—often yeast. Most labs try to optimize the signal peptide, the bit that helps shuttle the enzyme out of the cell, for higher yields. Custom, evolved signal peptides have worked in the classic yeast Saccharomyces cerevisiae. So, do they also work in K. phaffii? Not so much.
Key takeaway:
In K. phaffii, the native signal peptide from A. aegerita outperformed engineered versions by a wide margin.
Crude secretate activity was five to seven times higher than with S. cerevisiae-evolved signal peptides.
This means more enzyme, less hassle, and potentially better scalability for researchers working with UPOs.
For peptide production, this is a reminder: Host context matters. What works in one yeast doesn’t always translate to another. If you’re optimizing enzyme output, don’t overlook the original signal sequences.
For a deeper dive on current topics and techniques in peptide research, check out the peptide research index. Researchers looking to scale up or source key reagents can browse the vendor directory. Sometimes, nature’s blueprint is still the best starting point.
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