Switchable enzyme mimics based on self-assembled peptides for polyethylene terephthalate degradation

Area of Science:

• Biochemistry
• Materials Science
• Environmental Science

Background:

• Polyethylene terephthalate (PET) is a prevalent plastic pollutant due to its environmental persistence.
• Natural enzymes offer efficient degradation pathways but are not always suitable for industrial applications.

Purpose of the Study:

• To design and synthesize novel peptide-based enzyme mimics for the degradation of PET.
• To investigate the self-assembly behavior and catalytic activity of these enzyme mimics.

Main Methods:

• Enzyme mimics were constructed by combining serine, histidine, and aspartate active sites with a self-assembling polypeptide (MAX).
• Peptide conformational changes (random coil to β-sheet) were induced by altering pH and temperature.
• The structure-activity relationship of the enzyme mimics was analyzed to understand degradation efficiency.

Main Results:

• The designed peptides underwent pH and temperature-dependent conformational transitions, forming β-sheet structures in self-assembled fibrils.
• These β-sheet fibrils demonstrated efficient catalytic activity for PET degradation.
• Differences in hydrophobic residues influenced the catalytic activity of the enzyme mimics.

Conclusions:

• Self-assembled peptide enzyme mimics show significant potential for PET degradation.
• Stable fibril formation and ordered molecular conformation are key to high catalytic activity.
• Hydrogen bonding and hydrophobic interactions play crucial roles in promoting PET hydrolysis.