From Fiji to the Lab Bench: Unlocking a Hidden Enzyme

Writing and photography by Sonal Gupta from the Jefferies lab, Michael Smith Laboratories

A new study from the Brumer lab at the Michael Smith Laboratories has shed light on a fascinating and underexplored family of enzymes found in fungi – and the findings could open doors to greener, more efficient practices in industrial chemistry.

The PhD behind the work

Dr. Jessica Fong works on one of her experiments.

This study, published in the Biochemical Journal, is the culmination of Dr. Jessica Kalyun Fong’s PhD research under the supervision of Dr. Harry Brumer (Michael Smith Laboratories, Department of Chemistry).

Jess’s path into biochemistry was anything but conventional. Originally from Fiji, she came to Canada as a first-generation scholar, navigating a new country and a new academic system by asking questions and building connections along the way.

“My seniors were always there for guidance. The friends and network I built were everything during my PhD journey,” recalls Jess.

Building that network included a pivotal exchange experience in Germany, which introduced her to new scientific perspectives and opportunities. It was the combination of that exchange, the strong mentorship from Dr. Brumer – whose expertise in protein biochemistry and structural biology gave the project its backbone – and her own determination that made the work possible.

A family of versatile catalysts

Jess’s work presents the first experimental crystal structure of a specific fungal enzyme, an aldehyde oxidase in subfamily 1 of the Auxiliary Activity Family 5 (AA5) in Fusarium graminearum. This experimental structure has revealed a surprisingly distinct active site compared to its closest relative in subfamily 2, galactose oxidase.

The AA5 enzyme family at the heart of this research has a remarkable ability: it can handle a broad range of substrates, converting alcohol or aldehyde groups into carbonyls. Carbonyl compounds can be transformed to have many different chemical functionalities and can also be used as building blocks for the synthesis of pharmaceuticals, functional materials, and natural products. Different laboratories around the world are exploring this versatility for diverse industrial applications, drawn especially to the potential for more environmentally friendly enzymatic processes.

Up until this point, subfamily 1 has had very few characterized members, making Jess’s structural work even more significant. While the active sites of both subfamilies are nearly identical, their substrate preferences differ in a key way: subfamily 2 enzymes are active on alcohol substrates, while subfamily 1 enzymes like the one Jess studied oxidize aldehyde groups.

“What drew me in was the cool mechanism by which this enzyme works,” shares Jess. “There’s a fundamental question about how different activities arise when the active site is so similar – and that’s what we had set out to explore.”

Why it matters

Solving the crystal structure of this enzyme for the first time means researchers can now ask questions that were simply out of reach before, such as: What makes this enzyme prefer aldehyde substrates? And, how can that selectivity be engineered or applied? The structural data provides a foundation for future work in enzyme design, synthetic biology, and sustainable chemistry.

Reflecting on the process

When experiments stalled or results didn’t turn out as hoped, Jess learned to lean on the science itself to stay grounded. In quieter moments, she also found it helped to do something creative – for her, this was knitting, especially sweaters.

For young scientists interested in the field, Jess and Dr. Brumer’s advice is to ask questions early, to build your network, and to not be discouraged when experiments don’t go as expected.