Chemistry

Materials science

Engineering

Composite material

Biochemistry

Telecommunications

Biodegradation

Enzyme

Rational design

Nanotechnology

Organic chemistry

Degradation (telecommunications)

Computer science

Thermal stability

Polyethylene terephthalate

Chemical engineering

Protein engineering

ACS Catalysis

Widespread utilization of polyethylene terephthalate (PET) has caused a variety of environmental and health problems; thus, the enzymatic degradation of PET can be a promising solution. Although PETase from Ideonalla sakaiensis (IsPETase) has been reported to have the highest PET degradation activity under mild conditions of all PET-degrading enzymes reported to date, its low thermal stability limits its ability for efficient and practical enzymatic degradation of PET. Using the structural information on IsPETase, we developed a rational protein engineering strategy using several IsPETase variants that were screened for high thermal stability to improve PET degradation activity. In particular, the IsPETaseS121E/D186H/R280A variant, which was designed to have a stabilized β6-β7 connecting loop and extended subsite IIc, had a Tm value that was increased by 8.81 °C and PET degradation activity was enhanced by 14-fold at 40 °C in comparison with IsPETaseWT. The designed structural modifications were further verified through structure determination of the variants, and high thermal stability was further confirmed by a heat-inactivation experiment. The proposed strategy and developed variants represent an important advancement for achieving the complete biodegradation of PET under mild conditions.

Rational Protein Engineering of Thermo-Stable PETase from <i>Ideonella sakaiensis</i> for Highly Efficient PET Degradation

Rational Protein Engineering of Thermo-Stable PETase from Ideonella sakaiensis for Highly Efficient PET Degradation