PETase: Engineering and characterization of a plastic "eating" enzyme

Plastic pollution has reached alarming levels in the environment, particularly in our oceans. From documentary programs such as Blue Planet II, through to media from around the globe, the sheer scale of the problem is now receiving the attention that it deserves. One of the most common plastics, polyethylene terephthalate, or PET, is made from simple monomer building blocks that are linked together via ester bonds, hence the name polyesters. Plastics such as PET incredible properties and have revolutionized many industries, however, their recalcitrance to biodegradation is a critical problem. Unfortunately, the financial incentives to recycle plastics is minimal much ends up in landfills or is incinerated. The long-term solution to this problem is clearly two-fold: first, we must reduce our reliance on single-use plastic and second, simultaneously, develop better reclamation and recycling methods that are truly circular and sustainable.

 Recently, a newly discovered bacterium, Ideonella sakaiensis 201-F6, was shown to exhibit the rare ability to grow on PET as a major carbon and energy source. Central to its PET biodegradation capability is a secreted PETase (PET-digesting enzyme). In this talk, I will present a 0.92 Å resolution X-ray crystal structure of PETase and discuss the "engineering" and characterization of this enzyme for enhanced PET breakdown. 

I will also discuss our ongoing work to develop state-of-the-art computational techniques for efficiently and accurately computing the free energies of (bio)chemical processes using hybrid quantum mechanical/molecular mechanical (QM/MM) techniques.