Title : Improvement of thermostability and activity of PET-degrading enzyme Cut190 towards a detailed understanding and application of the enzymatic reaction mechanism - Numoto_2023_bioRxiv__ |
Author(s) : Numoto N , Kamiya N , Oda M |
Ref : Biorxiv , : , 2023 |
Abstract :
Enzymes capable of hydrolyzing polyethylene terephthalate (PET) and other plastics are attractive catalysts for application to the recycling of plastic waste due to their generally low environmental impact. Cut190 is a cutinase from a thermophilic actinomycete and shows PET-degrading activity and high thermal stability. We developed a series of Cut190 mutants exhibiting further improvements in thermal stability and activity, and showed that the unique stabilization and activation mechanism was dependent on Ca2+ ions. Two of these mutants, Cut190** and Cut190*SS, differed from the previous mutant Cut190* by deletion of the three C-terminal residues and introduction of five substitutions, including two cysteines forming a disulfide-bond, respectively. These mutants exhibit higher thermal stability and activity, which are often mutually exclusive characteristics. Crystallographic studies of these mutants and their inactivated derivatives demonstrated that they could have a novel ejecting form that would be responsible for releasing products. We also determined the crystal structures of ligand-bound complexes, which revealed the molecular mechanisms of the aromatic-ring recognition and the tetrahedral intermediate during the substrate cleaving, although the ligands had no aromatic ring but a cyclic group. This structural information provides insights into the mechanism of the Ca2+ -dependent PET-cleaving activity of Cut190 and provides a useful basis for further mutant design and computational studies. |
PubMedSearch : Numoto_2023_bioRxiv__ |
PubMedID: |
Gene_locus related to this paper: sacvd-c7mve8 |
Gene_locus | sacvd-c7mve8 |
Structure | 8IBL 8IBM |
Numoto N, Kamiya N, Oda M (2023)
Improvement of thermostability and activity of PET-degrading enzyme Cut190 towards a detailed understanding and application of the enzymatic reaction mechanism
Biorxiv
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Numoto N, Kamiya N, Oda M (2023)
Biorxiv
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