Department of Chemistry and Biochemistry Seminar
- Friday, December 13, 2019 at 3:10pm
- Chemistry & Biochemistry Building, Byker Auditorium - view map
Ece Topuzlu will discuss her recent findings from her PhD dissertation in a seminar titled "Characterization and Engineering of MHETase, a Plastic Degrading Polyesterase." Ece completed all PhD degree requirements in September of 2019 but did some additioinal data collection and analysis for the past two months in the lab of Dr. Gregg Beckham at NREL. Ece's research advisor is Valérie Copié .
Abstract: Accumulation of synthetic plastics in the biosphere is leading to a global environmental crisis. In response, microbes are evolving strategies to convert man-made polymers into carbon and energy sources, and these systems offer a promising starting point to harness for biotechnological purposes towards plastics upcycling. To that end, Ideonella sakaiensis 201-F6 was recently reported to secrete a two-enzyme system to deconstruct the abundant synthetic polyester, polyethylene terephthalate (PET), to its constituent monomers for further catabolism. The PETase enzyme specifically breaks down the PET polymer, liberating mono-(2-hydroxyethyl) terephthalate (MHET), which is then cleaved to its constituent monomers, terephthalic acid and ethylene glycol, by MHETase. This talk will focus on the structure and function of MHETase. Crystal structured of MHETase solved at 1.6 Å reveals an α/β hydrolase fold with an additional lid domain. In addition, we have expressed and purified multiple mutants of MHETase and PETase to assess the function of the lid domain, and we have identified homologous enzymes from two other organisms also turnover MHET. Lastly, we have explored further into the synergistic reactions of PETase and MHETase together and constructed chimeras for assessing the optimum PET turnover. Taken together, these results offer new molecular-level insights into the two-enzyme system of I. sakaiensis in the breakdown of recalcitrant PET.
- Department of Chemistry and Biochemistry