Computational biotransformation of polyethylene terephthalate by depolymerase: A QM/MM approach

Area of Science:

• Biochemistry
• Environmental Science
• Computational Chemistry

Background:

• Polyethylene Terephthalate (PET) production is increasing despite environmental concerns.
• Effective PET degradation strategies are urgently needed for environmental remediation.

Purpose of the Study:

• To systematically explore the biotransformation of PET by leaf-branch compost cutinase (LCC).
• To elucidate the catalytic mechanism and identify key features influencing PET degradation.

Main Methods:

• Utilized Molecular Dynamics (MD) and Quantum Mechanics/Molecular Mechanics (QM/MM) approaches.
• Analyzed the four concerted steps of the catalytic cycle.
• Identified rate-determining step and key molecular features.

Main Results:

• Deacylation identified as the rate-determining step with a calculated energy barrier.
• Observed unprecedented hydrogen bond length fluctuations during PET transformation.
• Established correlations between activation energies and key molecular features.

Conclusions:

• The study provides new insights into the catalytic mechanism of hydrolases, specifically LCC.
• Findings shed light on efficient recycling strategies for Polyethylene Terephthalate (PET).
• Hydrogen bond fluctuations may be a common feature in catalytic triad enzymes.