Enzymatic Biodegradation by Exploring the Rational Protein Engineering of the Polyethylene Terephthalate Hydrolyzing Enzyme PETase from Ideonella sakaiensis 201-F6

Recently, inclusion of polymer chemistry was mandated by the ACS in their guidelines for Bachelor's Degree Programs. While the discipline of biochemistry inherently focuses on natural polymers, rarely are synthetic polymers discussed in undergraduate biochemistry courses. Given the ubiquitous nature of synthetic polymers and their ever growing presence in the environment, efforts are being made to consider the use of enzymes as potential remediation agents to degrade persistent polymers. In particular, polyethylene terephthalate (PET) has garnered significant attention because of its wide use in single-serving beverage containers, their accumulation in oceans and landfills, and their lifetimes of hundreds of years. The newly identified bacteria Ideonella sakaiensis 201-F6 provides an opportunity to bridge the topics of synthetic and natural polymers because of its expression of the enzyme PETase, which functions to degrade PET and allows the bacteria to utilize the degradation products for assimilation. This chapter is intended to introduce undergraduate biochemistry students to the topic of synthetic polymer biodegradation by focusing on the structure of PETase and the rational protein engineering that has been performed to enhance its thermal stability and activity. These seminal studies provide promising results toward being able to commercially produce a biological agent to reduce PET environmental accumulation and will likely be used as a template for future protein engineering of enzymes that degrade other polymers.