Mican J

References (4)

Title : Exploring new galaxies: Perspectives on the discovery of novel PET-degrading enzymes - Mican_2024_Appl.Catal.B.Environmental_342_123404
Author(s) : Mican J , Jaradat DMM , Liu W , Weber G , Mazurenko S , Bornscheuer UT , Damborsky J , Wei R , Bednar D
Ref : Applied Catalysis B: Environmental , 342 :123404 , 2024
Abstract : Polyethylene terephthalate (PET) is a widely used polyester due to its beneficial material properties and low cost. However, PET contributes significantly to the growing problem of plastic waste pollution. Enzymatic PET recycling has emerged as a promising alternative to conventional mechanical and chemical recycling methods. While many PET hydrolases belonging to the a/-hydrolase fold superfamily have been discovered, the wild-type enzymes obtained from natural sources are not optimal for industrial conditions and need to be optimized through rational design or directed evolution to improve their efficiency and stability. This Perspective summarizes case studies of engineered PET hydrolases and proposes a workflow that tightly integrates a variety of in silico and high-throughput approaches for biochemical and structural characterization to accelerate the discovery of PET-degrading enzymes, also with novel structural scaffolds. These biocatalysts could be candidates for developing further innovative plastic recycling techniques.
ESTHER : Mican_2024_Appl.Catal.B.Environmental_342_123404
PubMedSearch : Mican_2024_Appl.Catal.B.Environmental_342_123404

Title : Multiple Substrate Binding Mode-Guided Engineering of a Thermophilic PET Hydrolase - Pfaff_2022_ACS.Catalysis_12_9790
Author(s) : Pfaff L , Gao J , Li Z , Jackering A , Weber G , Mican J , Chen Y , Dong W , Han X , Feiler CG , Ao YF , Badenhorst CPS , Bednar D , Palm GJ , Lammers M , Damborsky J , Strodel B , Liu W , Bornscheuer UT , Wei R
Ref : ACS Catal , 12 :9790 , 2022
Abstract : Thermophilic polyester hydrolases (PES-H) have recently enabled biocatalytic recycling of the mass-produced synthetic polyester polyethylene terephthalate (PET), which has found widespread use in the packaging and textile industries. The growing demand for efficient PET hydrolases prompted us to solve high-resolution crystal structures of two metagenome-derived enzymes (PES-H1 and PES-H2) and notably also in complex with various PET substrate analogues. Structural analyses and computational modeling using molecular dynamics simulations provided an understanding of how product inhibition and multiple substrate binding modes influence key mechanistic steps of enzymatic PET hydrolysis. Key residues involved in substratebinding and those identified previously as mutational hotspots in homologous enzymes were subjected to mutagenesis. At 72 C, the L92F/Q94Y variant of PES-H1 exhibited 2.3-fold and 3.4-fold improved hydrolytic activity against amorphous PET films and pretreated real-world PET waste, respectively. The R204C/S250C variant of PES-H1 had a 6.4 C higher melting temperature than the wild-type enzyme but retained similar hydrolytic activity. Under optimal reaction conditions, the L92F/Q94Y variant of PES-H1 hydrolyzed low-crystallinity PET materials 2.2-fold more efficiently than LCC ICCG, which was previously the most active PET hydrolase reported in the literature. This property makes the L92F/ Q94Y variant of PES-H1 a good candidate for future applications in industrial plastic r"cycling processes.
ESTHER : Pfaff_2022_ACS.Catalysis_12_9790
PubMedSearch : Pfaff_2022_ACS.Catalysis_12_9790
PubMedID: 35966606
Gene_locus related to this paper: 9firm-PHL7

Title : Mechanism-Based Design of Efficient PET Hydrolases - Wei_2022_ACS.Catal_12_3382
Author(s) : Wei R , von Haugwitz G , Pfaff L , Mican J , Badenhorst CPS , Liu W , Weber G , Austin HP , Bednar D , Damborsky J , Bornscheuer UT
Ref : ACS Catal , 12 :3382 , 2022
Abstract : Polyethylene terephthalate (PET) is the most widespread synthetic polyester, having been utilized in textile fibers and packaging materials for beverages and food, contributing considerably to the global solid waste stream and environmental plastic pollution. While enzymatic PET recycling and upcycling have recently emerged as viable disposal methods for a circular plastic economy, only a handful of benchmark enzymes have been thoroughly described and subjected to protein engineering for improved properties over the last 16 years. By analyzing the specific material properties of PET and the reaction mechanisms in the context of interfacial biocatalysis, this Perspective identifies several limitations in current enzymatic PET degradation approaches. Unbalanced enzyme-substrate interactions, limited thermostability, and low catalytic efficiency at elevated reaction temperatures, and inhibition caused by oligomeric degradation intermediates still hamper industrial applications that require high catalytic efficiency. To overcome these limitations, successful protein engineering studies using innovative experimental and computational approaches have been published extensively in recent years in this thriving research field and are summarized and discussed in detail here. The acquired knowledge and experience will be applied in the near future to address plastic waste contributed by other mass-produced polymer types (e.g., polyamides and polyurethanes) that should also be properly disposed by biotechnological approaches.
ESTHER : Wei_2022_ACS.Catal_12_3382
PubMedSearch : Wei_2022_ACS.Catal_12_3382
PubMedID: 35368328

Title : Promiscuous Dehalogenase Activity of the Epoxide Hydrolase CorEH from Corynebacterium sp. C12 - Schuiten_2021_ACS.Catal_11_6113
Author(s) : Schuiten ED , Badenhorst CPS , Palm GJ , Berndt L , Lammers M , Mican J , Bednar D , Damborsky J , Bornscheuer UT
Ref : ACS Catal , 11 :6113 , 2021
Abstract : Haloalkane dehalogenases and epoxide hydrolases are phylogenetically related and structurally homologous enzymes that use nucleophilic aspartate residues for an SN2 attack on their substrates. Despite their mechanistic similarities, no enzymes are known that exhibit both epoxide hydrolase and dehalogenase activity. We screened a subset of epoxide hydrolases, closely related to dehalogenases, for dehalogenase activity and found that the epoxide hydrolase CorEH from Corynebacterium sp. C12 exhibits promiscuous dehalogenase activity. Compared to the hydrolysis of epoxides like cyclohexene oxide (1.41 micromol min-1 mg-1), the dehalogenation of haloalkanes like 1-bromobutane (0.25 nmol min-1 mg-1) is about 5000-fold lower. In addition to the activity with 1-bromobutane, dehalogenase activity was detected with other substrates like 1-bromohexane, 1,2-dibromoethane, 1-iodobutane, and 1-iodohexane. This study shows that dual epoxide hydrolase and dehalogenase activity can be present in one naturally occurring protein scaffold.
ESTHER : Schuiten_2021_ACS.Catal_11_6113
PubMedSearch : Schuiten_2021_ACS.Catal_11_6113
Gene_locus related to this paper: corsp-cEH