Rational Protein Engineering to Increase the Activity and Stability of IsPETase Using the PROSS Algorithm

Area of Science:

• Biotechnology
• Biochemistry
• Materials Science

Background:

• Polyethylene terephthalate (PET) is a widely used plastic with limited recycling options due to quality degradation.
• Enzymatic hydrolysis offers a sustainable alternative for PET recycling by breaking it down into monomers.
• Current enzymes like IsPETase show promise but lack sufficient thermal stability for industrial application.

Purpose of the Study:

• To improve the thermal stability and activity of IsPETase for enhanced polyethylene terephthalate (PET) degradation.
• To identify specific mutations in IsPETase that increase its performance under moderate temperature conditions.

Main Methods:

• Utilized sequence and structure-based bioinformatics to predict beneficial mutations in IsPETase.
• Introduced and tested the S136E amino acid substitution to assess its impact on enzyme activity and stability.

Main Results:

• The S136E mutation significantly increased the thermal stability and activity of IsPETase.
• The S136E variant demonstrated a 3.3-fold increase in PET degradation activity compared to the wild-type enzyme.
• This previously unreported variant shows potential for more efficient and sustainable PET recycling.

Conclusions:

• The S136E mutation represents a significant advancement in enzyme engineering for PET recycling.
• Enhanced IsPETase offers a viable pathway for infinite recycling of polyethylene terephthalate (PET) plastics.
• This research contributes to developing more sustainable plastic waste management strategies.