Insight into how PETase Functions at the Solid-Liquid Interface and an Activity-Stability Trade-Off.

Area of Science:

• Biochemistry
• Enzymology
• Materials Science

Background:

• Enzymatic degradation of poly(ethylene terephthalate) (PET) is crucial for sustainable plastic recycling.
• The molecular mechanisms of PETase activity at the solid-liquid interface are not fully understood, limiting enzyme optimization.

Purpose of the Study:

• To elucidate the detailed catalytic pathway of PETase at the PET solid-liquid interface.
• To identify factors limiting PET degradation efficiency and to engineer improved PETase variants.

Main Methods:

• Detailed analysis of the PETase catalytic pathway, including enzyme adsorption, substrate capture, and ester bond cleavage.
• Investigation of the trade-off between enzyme activity and stability in PET-binding loops.
• Protein engineering strategies to modify loop dynamics and enhance enzyme performance.

Main Results:

• The study maps the complete catalytic steps of PETase, from interface adsorption to bond cleavage.
• A key finding is the inverse relationship between the activity and stability of PET-binding loops, hindering degradation.
• Engineering PETase loops successfully enhanced both enzymatic activity and structural stability.

Conclusions:

• This research provides fundamental insights into PETase function at interfaces.
• The findings offer a rational design strategy for developing more efficient plastic-degrading enzymes for PET recycling.