International collaboration reveals a new role for water in enzymes. A novel water-mediated catalytic architecture is discovered in CE20 family enzymes

Researchers from the Brazilian Center for Research in Energy and Materials (CNPEM) and the University of Greifswald (Germany) described an unprecedented architecture in the functioning of enzymes involved in the modification of complex sugars

 

The work was published on July 31, 2025 in the journal Nature Communications and expands fundamental knowledge about how enzymes act in the conversion of polysaccharides — an essential step for industrial processes ranging from food processing to biofuel production.

What was discovered

The enzymes studied belong to the CE20 family, a group of biocatalysts that can remove small chemical parts (esters) attached to larger sugars. This modification alters the physical properties of these molecules and facilitates the access of other enzymes that will act on them in subsequent stages, making the degradation process more efficient.

In general, this type of enzyme works thanks to a catalytic triad — three amino acids that work together to speed up the chemical reaction. But, when analyzing two CE20 enzymes, researchers found something surprising: one of the classic components was missing. In its place was a perfectly organized water molecule, which took on the role that would normally be played by an amino acid.

This new architecture, named the “water-mediated catalytic triad”, was confirmed in additional experiments, which showed that the water molecule is not just a solvent, but an active and indispensable element of the reaction.

 

 

Cutting-edge infrastructure in Brazil

The enzymes’ detailed characterization was only possible thanks to different open research facilities at CNPEM:

– the Manacá beamline, at the Sirius/LNLS particle accelerator, used to collect high-resolution X-ray diffraction data;

– the Robolab, at the Brazilian Biosciences National Laboratory (LNBio), which automates molecular biology and crystallization experiments;

– and the macromolecule biophysics platform at the Brazilian Biorenewables National Laboratory (LNBR), essential for functional studies of proteins.

In Manacá, for example, the crystals were frozen in liquid nitrogen at 100 K (approximately -173 °C) and analyzed with the Pilatus 2M detector. Approximately 3,600 images were collected per crystal, with high precision, revealing the role of the water molecule in the active structure of the enzyme.

Scientific and technological impact

For biochemist Michael Lammers, from the University of Greifswald, the result significantly expands our understanding of enzyme catalysis:

“Our results show that water is not just a solvent, but can actively participate in the reaction. It is a previously unknown mechanism that substantially expands our understanding of enzymes.”

In addition to fundamental relevance, the discovery could boost industrial applications by guiding the development of more efficient and sustainable biocatalysts, useful both for the production of second-generation biofuels and for the food and biotechnology industries.

Plínio Vieira, researcher from the Brazilian Biorenewables National Laboratory at CNPEM, adds that “the most striking thing about this work was realizing how the diversity of perspectives enriches science”. “The exchange of perspectives and ways of thinking provided immense learning about how collaboration can accelerate discoveries and open up paths that, alone, we might not have noticed. It was precisely this exchange that led us to see beyond the obvious and understand that the enzyme acted in a different way, mediated by a water molecule. It’s a detail that changes the way we understand the common mechanism of this class of proteins”, he says.

Collaboration instead of competition

The study arose from a meeting between research groups from Germany and Brazil, who realized they were investigating similar questions. Instead of competing for publishing primacy, they decided to join forces. For Mario Murakami, director of the Brazilian Biorenewables National Laboratory (LNBR/CNPEM) and leader of the work in Brazil, this is one of the great legacies of the project:

“It’s impressive to see how a situation that could easily have generated competition ended up resulting in such a robust article. The willingness of Professor Uwe Bornscheuer and Michael Lammers to join forces, rather than prioritizing rapid publication, made all the difference. This

open collaboration not only strengthened the scientific output, but also left a lasting example of what science can achieve when we choose to build together.”

Institutional support

The project was funded by the Deutsche Forschungsgemeinschaft (DFG – German Research Foundation), within the scope of the POMPU research unit, and the São Paulo Research Foundation (FAPESP) in Brazil. The research also connects to the recently approved Transregio/CRC CONCENTRATE collaborative consortium.

________________________________________________________________________ Read the article in Nature Communications