Mapping the sequence landscape of an artificial enzyme
The rising environmental concerns regarding today’s manufacturing processes urgently demand cleaner and more sustainable approaches. One promising route is the use of enzymes, which can replace harsh chemical methods with eco-friendly alternatives. However, natural enzymes evolved to meet life’s needs, not for the production of medicines or fine chemicals. To unlock new possibilities, artificial enzymes are being created to carry out reactions not found in nature. Unfortunately, these man-made versions are often less efficient, requiring clever engineering to reach real-world usefulness.
In his research, Fabrizio Casilli set out to understand how the internal motions (conformational dynamics) shape enzyme catalytic efficiency by exploring the effect of long-range interactions. Casilli focused on a well-known artificial enzyme scaffold, LmrR, for which he developed a colorimetric high-throughput activity assay that can test thousands of protein variants at the same time. Casilli discovered mutations remote from the enzyme active site that reshape its internal dynamics and establish unexpected epistatic interactions, namely where the effect of one mutation depends on another. Ultimately, he was able to create a new variant with nearly 400-times higher activity than the unevolved enzyme.
This work shows that by steering enzymes toward more productive dynamic states and targeting the intricate networks of interactions that shape their function, we can accelerate the creation of efficient biocatalysts. In the future, such strategies will help deliver sustainable, tailor-made enzymes to support greener and more efficient chemical manufacturing.