Computational redesign of a hydrolase for nearly complete PET depolymerization at industrially relevant high-solids...

Area of Science:

• Biotechnology
• Environmental Science
• Biochemistry

Background:

• Biotechnological plastic recycling offers a promising solution to the global plastic pollution crisis.
• Current methods for poly(ethylene terephthalate) (PET) biodegradation, while advanced, leave a residual 10% of non-degradable material.
• Addressing this limitation is crucial for achieving efficient and comprehensive PET recycling.

Purpose of the Study:

• To engineer a more efficient PET hydrolase enzyme using computational strategies.
• To overcome the limitations of existing enzymes in achieving complete PET depolymerization.
• To advance the field of industrial polyester hydrolase engineering.

Main Methods:

• Utilized a computational strategy to redesign a hydrolase enzyme from the bacterium HR29.
• Engineered a variant named TurboPETase with enhanced PET-degrading capabilities.
• Conducted kinetic and structural analysis to understand the enzyme's improved performance.

Main Results:

• The engineered TurboPETase demonstrated superior performance compared to other known PET hydrolases.
• Achieved nearly complete depolymerization of PET within 8 hours at a solids loading of 200 g/kg.
• Identified a more flexible PET-binding groove as a key factor in TurboPETase's enhanced activity.

Conclusions:

• TurboPETase represents a significant advancement in the engineering of industrially applicable polyester hydrolases.
• The findings provide valuable insights into enzyme design for improved polymer degradation.
• This work offers guidance for future efforts in developing biocatalysts for recycling other polymer types.