A distant enzyme loop can make PET breakdown more efficient

Improving an enzyme does not always mean changing the chemistry right next to its active site. Researchers showed that reshaping a surface region about 25 Å away can improve productive access to PET.

What they found

The study focuses on CaPETase, an enzyme able to hydrolyze polyethylene terephthalate (PET). The researchers identified a protruding C-terminal surface loop that restricted productive access to PET. Replacing it with a non-protruding version increased depolymerization even though the loop sits far from the catalytic site.

Why it matters

The result suggests another route for designing better plastic-degrading enzymes: not only optimizing the active site's chemistry, but also improving how the enzyme approaches the plastic surface. The researchers tested the concept across representative PETases, suggesting broader potential.

What it does not mean

It does not mean an enzyme is ready to make environmental plastic disappear. This work concerns controlled PET depolymerization and remains laboratory research. Scaling a mechanistic improvement into a reliable recycling process is a separate challenge.