Hawkins MA

References (2)

Title : Comparative Performance of PETase as a Function of Reaction Conditions, Substrate Properties, and Product Accumulation - Erickson_2022_ChemSusChem_15_e202102517
Author(s) : Erickson E , Shakespeare TJ , Bratti F , Buss BL , Graham R , Hawkins MA , Konig G , Michener WE , Miscall J , Ramirez KJ , Rorrer NA , Zahn M , Pickford AR , McGeehan JE , Beckham GT
Ref : ChemSusChem , 15 :e202102517 , 2022
Abstract : Invited for this month's cover is the BOTTLE Consortium, featuring Gregg Beckham's laboratory from NREL and John McGeehan's laboratory from the University of Portsmouth. The cover image shows the application of poly(ethylene terephthalate) (PET) hydrolase enzymes on post-consumer waste plastic, towards the development of an enzymatic PET recycling strategy. The Full Paper itself is available at 10.1002/cssc.202101932.
ESTHER : Erickson_2022_ChemSusChem_15_e202102517
PubMedSearch : Erickson_2022_ChemSusChem_15_e202102517
PubMedID: 34914860

Title : Comparative performance of PETase as a function of reaction conditions, substrate properties, and product accumulation - Erickson_2022_ChemSusChem_15_e202101932
Author(s) : Erickson E , Shakespeare TJ , Bratti F , Buss BL , Graham R , Hawkins MA , Konig G , Michener WE , Miscall J , Ramirez KJ , Rorrer NA , Zahn M , Pickford AR , McGeehan JE , Beckham G
Ref : ChemSusChem , 15 : , 2022
Abstract : There is keen interest to develop new technologies to recycle the plastic poly(ethylene terephthalate) (PET). To this end, the use of PET-hydrolyzing enzymes has shown promise for PET deconstruction to its monomers, terephthalate (TPA) and ethylene glycol (EG). Here, we compare the Ideonella sakaiensis PETase wild-type enzyme to a previously reported improved variant (W159H/S238F). We compare the thermostability of each enzyme and describe a 1.45 A resolution structure of the mutant, highlighting changes in the substrate binding cleft compared to the wild-type enzyme. Subsequently, the performance of the wild-type and variant enzyme was compared as a function of temperature, substrate morphology, and reaction mixture composition. These studies show that reaction temperature has the strongest influence on performance between the two enzymes. We also show that both enzymes achieve higher levels of PET conversion for substrates with moderate crystallinity relative to amorphous substrates. Finally, we assess the impact of product accumulation on reaction progress for the hydrolysis of both PET and bis(2-hydroxyethyl) terephthalate (BHET). Each enzyme displays different inhibition profiles to mono(2-hydroxyethyl) terephthalate (MHET) and TPA, while both are sensitive to inhibition by EG. Overall, this study highlights the importance of reaction conditions, substrate selection, and product accumulation for catalytic performance of PET-hydrolyzing enzymes, which have implications for enzyme screening in the development of enzyme- based polyester recycling.
ESTHER : Erickson_2022_ChemSusChem_15_e202101932
PubMedSearch : Erickson_2022_ChemSusChem_15_e202101932
PubMedID: 34587366
Gene_locus related to this paper: idesa-peth