1
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Zhang Y, Hancock WO. Measuring PETase enzyme kinetics by single-molecule microscopy. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.04.24.590935. [PMID: 38712273 PMCID: PMC11071475 DOI: 10.1101/2024.04.24.590935] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2024]
Abstract
Polyethylene terephthalate (PET) is one of the most widely produced man-made polymers and is a significant contributor to microplastics pollution. The environmental and human health impacts of microplastics pollution have motivated a concerted effort to develop microbe- and enzyme-based strategies to degrade PET and similar plastics. A PETase derived from the bacteria Ideonella sakaiensis was previously shown to enzymatically degrade PET, triggering multidisciplinary efforts to improve the robustness and activity of this and other PETases. However, because these enzymes only erode the surface of the insoluble PET substrate, it is difficult to measure standard kinetic parameters, such as kon, koff and kcat, complicating interpretation of the activity of mutants using traditional enzyme kinetics frameworks. To address this challenge, we developed a single-molecule microscopy assay that quantifies the landing rate and binding duration of quantum dot-labeled PETase enzymes interacting with a surface-immobilized PET film. Wild-type PETase binding durations were well fit by a biexponential with a fast population having a 2.7 s time constant, interpreted as active binding events, and a slow population interpreted as non-specific binding interactions that last tens of seconds. A previously described hyperactive mutant, S238F/W159H had both a faster on-rate and a slower off-rate than wild-type PETase, potentially explaining its enhanced activity. Because this single-molecule approach provides a more detailed mechanistic picture of PETase enzymatic activity than standard bulk assays, it should aid future efforts to engineer more robust and active PETases to combat global microplastics pollution.
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Affiliation(s)
- Yuwei Zhang
- Department of Biomedical Engineering, Pennsylvania State University, University Park, Pennsylvania, USA
| | - William O. Hancock
- Department of Biomedical Engineering, Pennsylvania State University, University Park, Pennsylvania, USA
- Department of Chemistry, Pennsylvania State University, University Park, Pennsylvania, USA
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2
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McDonough R, Williams CC, Hartley CJ, French N, Scott C, Lewis DA. Kinetic Model for the Heterogeneous Biocatalytic Reactions Using Tethered Cofactors. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2024; 40:6685-6693. [PMID: 38525517 DOI: 10.1021/acs.langmuir.3c02958] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/26/2024]
Abstract
Understanding the mechanism of interfacial enzyme kinetics is critical to the development of synthetic biological systems for the production of value-added chemicals. Here, the interfacial kinetics of the catalysis of β-nicotinamide adenine dinucleotide (NAD+)-dependent enzymes acting on NAD+ tethered to the surface of silica nanoparticles (SiNPs) has been investigated using two complementary and supporting kinetic approaches: enzyme excess and reactant (NAD+) excess. Kinetic models developed for these two approaches characterize several critical reaction steps including reversible enzyme adsorption, complexation, decomplexation, and catalysis of the surface-bound enzyme/NAD+ complex. The analysis reveals a concentrating effect resulting in a very high local concentration of enzyme and cofactor on the particle surface, in which the enzyme is saturated by surface-bound NAD, facilitating a rate enhancement of enzyme/NAD+ complexation and catalysis. This resulted in high enzyme efficiency within the tethered NAD+ system compared to that of the free enzyme/NAD+ system, which increases with decreasing enzyme concentration. The role of enzyme adsorption onto solid substrates with a tethered catalyst (such as NAD+) has potential for creating highly efficient flow biocatalytic systems.
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Affiliation(s)
- Rowan McDonough
- Institute for Nanoscale Science and Technology, School of Chemical and Physical Sciences, Flinders University, Bedford Park, SA 5042, Australia
| | | | | | - Nigel French
- CSIRO Environment, Black Mountain, ACT 2601, Australia
| | - Colin Scott
- CSIRO Environment, Black Mountain, ACT 2601, Australia
| | - David A Lewis
- Institute for Nanoscale Science and Technology, School of Chemical and Physical Sciences, Flinders University, Bedford Park, SA 5042, Australia
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3
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Zhong-Johnson EZL, Dong Z, Canova CT, Destro F, Cañellas M, Hoffman MC, Maréchal J, Johnson TM, Zheng M, Schlau-Cohen GS, Lucas MF, Braatz RD, Sprenger KG, Voigt CA, Sinskey AJ. Analysis of Poly(ethylene terephthalate) degradation kinetics of evolved IsPETase variants using a surface crowding model. J Biol Chem 2024; 300:105783. [PMID: 38395309 PMCID: PMC10963241 DOI: 10.1016/j.jbc.2024.105783] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2023] [Revised: 02/10/2024] [Accepted: 02/19/2024] [Indexed: 02/25/2024] Open
Abstract
Poly(ethylene terephthalate) (PET) is a major plastic polymer utilized in the single-use and textile industries. The discovery of PET-degrading enzymes (PETases) has led to an increased interest in the biological recycling of PET in addition to mechanical recycling. IsPETase from Ideonella sakaiensis is a candidate catalyst, but little is understood about its structure-function relationships with regards to PET degradation. To understand the effects of mutations on IsPETase productivity, we develop a directed evolution assay to identify mutations beneficial to PET film degradation at 30 °C. IsPETase also displays enzyme concentration-dependent inhibition effects, and surface crowding has been proposed as a causal phenomenon. Based on total internal reflectance fluorescence microscopy and adsorption experiments, IsPETase is likely experiencing crowded conditions on PET films. Molecular dynamics simulations of IsPETase variants reveal a decrease in active site flexibility in free enzymes and reduced probability of productive active site formation in substrate-bound enzymes under crowding. Hence, we develop a surface crowding model to analyze the biochemical effects of three hit mutations (T116P, S238N, S290P) that enhanced ambient temperature activity and/or thermostability. We find that T116P decreases susceptibility to crowding, resulting in higher PET degradation product accumulation despite no change in intrinsic catalytic rate. In conclusion, we show that a macromolecular crowding-based biochemical model can be used to analyze the effects of mutations on properties of PETases and that crowding behavior is a major property to be targeted for enzyme engineering for improved PET degradation.
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Affiliation(s)
| | - Ziyue Dong
- Department of Chemical and Biological Engineering, University of Colorado, Boulder, Colorado, USA
| | - Christopher T Canova
- Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA
| | - Francesco Destro
- Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA
| | | | - Mikaila C Hoffman
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA
| | - Jeanne Maréchal
- Department of Biology, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA; AgroParisTech, Palaiseau, France
| | - Timothy M Johnson
- Plasma Science and Fusion Center, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA
| | - Maya Zheng
- Department of Biology, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA
| | - Gabriela S Schlau-Cohen
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA
| | | | - Richard D Braatz
- Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA
| | - Kayla G Sprenger
- Department of Chemical and Biological Engineering, University of Colorado, Boulder, Colorado, USA
| | - Christopher A Voigt
- Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA
| | - Anthony J Sinskey
- Department of Biology, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA.
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4
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Cui Y, Chen Y, Sun J, Zhu T, Pang H, Li C, Geng WC, Wu B. Computational redesign of a hydrolase for nearly complete PET depolymerization at industrially relevant high-solids loading. Nat Commun 2024; 15:1417. [PMID: 38360963 PMCID: PMC10869840 DOI: 10.1038/s41467-024-45662-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2023] [Accepted: 01/30/2024] [Indexed: 02/17/2024] Open
Abstract
Biotechnological plastic recycling has emerged as a suitable option for addressing the pollution crisis. A major breakthrough in the biodegradation of poly(ethylene terephthalate) (PET) is achieved by using a LCC variant, which permits 90% conversion at an industrial level. Despite the achievements, its applications have been hampered by the remaining 10% of nonbiodegradable PET. Herein, we address current challenges by employing a computational strategy to engineer a hydrolase from the bacterium HR29. The redesigned variant, TurboPETase, outperforms other well-known PET hydrolases. Nearly complete depolymerization is accomplished in 8 h at a solids loading of 200 g kg-1. Kinetic and structural analysis suggest that the improved performance may be attributed to a more flexible PET-binding groove that facilitates the targeting of more specific attack sites. Collectively, our results constitute a significant advance in understanding and engineering of industrially applicable polyester hydrolases, and provide guidance for further efforts on other polymer types.
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Affiliation(s)
- Yinglu Cui
- AIM Center, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China.
| | - Yanchun Chen
- AIM Center, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China
| | - Jinyuan Sun
- AIM Center, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Tong Zhu
- AIM Center, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China
| | - Hua Pang
- AIM Center, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China
| | - Chunli Li
- AIM Center, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China
| | - Wen-Chao Geng
- AIM Center, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China
- College of Chemistry, Nankai University, Tianjin, China
| | - Bian Wu
- AIM Center, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China.
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5
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Thomsen TB, Radmer TS, Meyer AS. Enzymatic degradation of poly(ethylene terephthalate) (PET): Identifying the cause of the hypersensitive enzyme kinetic response to increased PET crystallinity. Enzyme Microb Technol 2024; 173:110353. [PMID: 37979402 DOI: 10.1016/j.enzmictec.2023.110353] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2023] [Revised: 11/01/2023] [Accepted: 11/01/2023] [Indexed: 11/20/2023]
Abstract
Plastic pollution poses a significant environmental challenge, with poly(ethylene terephthalate) (PET) being a major contributor due to its extensive use in single use applications such as plastic bottles and other packaging material. Enzymatic degradation of PET offers a promising solution for PET recycling, but the enzyme kinetics in relation to the degree of crystallinity (XC) of the PET substrate are poorly understood. In this study, we investigated the hypersensitive enzyme kinetic response on PET at XC from ∼8.5-12% at 50 °C using the benchmark PET hydrolysing enzyme LCCICCG. We observed a substantial reduction in the maximal enzymatic reaction rate (invVmax) with increasing XC, corresponding to a 3-fold reduction in invVmax when the XC of PET increased from 8.6% to 12.2%. The kinetic analysis revealed that the level of the Mobile Amorphous Fraction (XMAF) was a better descriptor for the enzymatic degradation rate response than XC (or (100%-XC)). By continuous monitoring of the enzymatic reaction progress, we quantified the lag phase prolongation in addition to the steady-state kinetic rates (vss) of the reactions and found that the duration of the lag phase of a reaction could be predicted from the vss and XC by multiple linear regression modeling. The linear correlation between the duration of the lag phase and the vss of the enzymatic PET degradation affirmed that the LCCICCG worked via a random/endo-type enzymatic attack pattern. The longer lag phase at increased XC of PET is proposed to be due to increased substrate entanglement density as well as unproductive enzyme binding to the crystalline regions of PET. The findings enhance our understanding of PET enzymatic degradation kinetics and its dependence on substrate composition, i.e., XMAF and XC.
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Affiliation(s)
- Thore Bach Thomsen
- Protein Chemistry and Enzyme Technology Section, Department of Biotechnology and Biomedicine, DTU Bioengineering, Technical University of Denmark, Building 221, 2800 Kgs. Lyngby, Denmark
| | - Tobias S Radmer
- Protein Chemistry and Enzyme Technology Section, Department of Biotechnology and Biomedicine, DTU Bioengineering, Technical University of Denmark, Building 221, 2800 Kgs. Lyngby, Denmark
| | - Anne S Meyer
- Protein Chemistry and Enzyme Technology Section, Department of Biotechnology and Biomedicine, DTU Bioengineering, Technical University of Denmark, Building 221, 2800 Kgs. Lyngby, Denmark.
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6
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Nousi A, Molina GA, Schiano-di-Cola C, Sørensen TH, Borch K, Pedersen JN, Westh P, Marie R. Impact of Synergy Partner Cel7B on Cel7A Binding Rates: Insights from Single-Molecule Data. J Phys Chem B 2024; 128:635-647. [PMID: 38227769 PMCID: PMC10824242 DOI: 10.1021/acs.jpcb.3c05697] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2023] [Revised: 01/02/2024] [Accepted: 01/05/2024] [Indexed: 01/18/2024]
Abstract
Enzymatic degradation of cellulosic biomass is a well-established route for the sustainable production of biofuels, chemicals, and materials. A strategy employed by nature and industry to achieve an efficient degradation of cellulose is that cellobiohydrolases (or exocellulases), such as Cel7A, work synergistically with endoglucanases, such as Cel7B, to achieve the complete degradation of cellulose. However, a complete mechanistic understanding of this exo-endo synergy is still lacking. Here, we used single-molecule fluorescence microscopy to quantify the binding kinetics of Cel7A on cellulose when it is acting alone on the cellulose fibrils and in the presence of its synergy partner, the endoglucanase Cel7B. To this end, we used a fluorescently tagged Cel7A and studied its binding in the presence of the unlabeled Cel7B. This provided the single-molecule data necessary for the estimation of the rate constants of association kON and dissociation kOFF of Cel7A for the substrate. We show that the presence of Cel7B does not impact the dissociation rate constant, kOFF. But, the association rate of Cel7A decreases by a factor of 2 when Cel7B is present at a molar proportion of 10:1. This ratio has previously been shown to lead to synergy. This decrease in association rate is observed in a wide range of total enzyme concentrations, from sub nM to μM concentrations. This decrease in kON is consistent with the formation of cellulase clusters recently observed by others using atomic force microscopy.
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Affiliation(s)
- Aimilia Nousi
- Department
of Health Technology, Technical University
of Denmark, 2800 Kongens Lyngby, Denmark
| | - Gustavo Avelar Molina
- Department
of Biotechnology and Biomedicine, Technical
University of Denmark, 2800 Kongens Lyngby, Denmark
- The
Novo Nordisk Foundation Center for Biosustainability, Technical University of Denmark, 2800 Kongens Lyngby, Denmark
| | | | | | - Kim Borch
- Novozymes
A/S, Krogshøjvej
36, 2880 Bagsværd, Denmark
| | - Jonas N. Pedersen
- Department
of Health Technology, Technical University
of Denmark, 2800 Kongens Lyngby, Denmark
| | - Peter Westh
- Department
of Biotechnology and Biomedicine, Technical
University of Denmark, 2800 Kongens Lyngby, Denmark
| | - Rodolphe Marie
- Department
of Health Technology, Technical University
of Denmark, 2800 Kongens Lyngby, Denmark
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7
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Wang Y, Svensson B, Henrissat B, Møller MS. Functional Roles of N-Terminal Domains in Pullulanase from Human Gut Lactobacillus acidophilus. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2023; 71:18898-18908. [PMID: 38053504 DOI: 10.1021/acs.jafc.3c06487] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/07/2023]
Abstract
Pullulanases are multidomain α-glucan debranching enzymes with one or more N-terminal domains (NTDs) including carbohydrate-binding modules (CBMs) and domains of unknown function (DUFs). To elucidate the roles of NTDs in Lactobacillus acidophilus NCFM pullulanase (LaPul), two truncated variants, Δ41-LaPul (lacking CBM41) and Δ(41+DUFs)-LaPul (lacking CBM41 and two DUFs), were produced recombinantly. LaPul recognized 1.3- and 2.2-fold more enzyme attack-sites on starch granules compared to Δ41-LaPul and Δ(41+DUFs)-LaPul, respectively, as measured by interfacial kinetics. Δ41-LaPul displayed markedly lower affinity for starch granules and β-cyclodextrin (10- and >21-fold, respectively) in comparison to LaPul, showing substrate binding mainly stems from CBM41. Δ(41+DUFs)-LaPul exhibited a 12 °C lower melting temperature than LaPul and Δ41-LaPul, indicating that the DUFs are critical for LaPul stability. Notably, Δ41-LaPul exhibited a 14-fold higher turnover number (kcat) and 9-fold higher Michaelis constant (KM) compared to LaPul, while Δ(41+DUFs)-LaPul's values were close to those of LaPul, possibly due to the exposure of aromatic by truncation.
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Affiliation(s)
- Yu Wang
- Enzyme and Protein Chemistry, Department of Biotechnology and Biomedicine, Technical University of Denmark, DK-2800 Kgs. Lyngby, Denmark
| | - Birte Svensson
- Enzyme and Protein Chemistry, Department of Biotechnology and Biomedicine, Technical University of Denmark, DK-2800 Kgs. Lyngby, Denmark
| | - Bernard Henrissat
- Enzyme Discovery, Department of Biotechnology and Biomedicine, Technical University of Denmark, DK-2800 Kgs. Lyngby, Denmark
| | - Marie Sofie Møller
- Applied Molecular Enzyme Chemistry, Department of Biotechnology and Biomedicine, Technical University of Denmark, DK-2800 Kgs. Lyngby, Denmark
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8
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Angeltveit CF, Jeoh T, Horn SJ. Lytic polysaccharide monooxygenase activity increases productive binding capacity of cellobiohydrolases on cellulose. BIORESOURCE TECHNOLOGY 2023; 389:129806. [PMID: 37769978 DOI: 10.1016/j.biortech.2023.129806] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/14/2023] [Revised: 09/25/2023] [Accepted: 09/25/2023] [Indexed: 10/03/2023]
Abstract
Cellobiohydrolases are crucial for cellulose breakdown, but their efficiency on crystalline cellulose is hampered by limited access to single chain ends to initiate hydrolysis. As a result, they depend on enzymes like lytic polysaccharide monooxygenases (LPMOs), which directly target the crystalline cellulose surface. This study investigated how LPMO pretreatment affected the productive binding capacity of a Trichoderma longibrachiatum cellobiohydrolase, TlCBHI, on crystalline cellulose by applying an amperometric cellobiose dehydrogenase biosensor. After the 24-hour of LPMO pretreatment, the productive binding capacity of TlCBHI significantly increased in all reactions. However, with a shorter 5-hour LPMO pretreatment, minimal to no effect on productive binding capacity was observed. Of note, all LPMO reactions were inactivated around this time point. This delayed LPMO effect suggests that the improved binding capacity for cellulases does not directly result from cellulose chain cleavage by LPMOs but rather from the cellulose decrystallization following the oxidative cleavage.
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Affiliation(s)
- Camilla F Angeltveit
- Faculty of Chemistry, Biotechnology, and Food Science, Norwegian University of Life Sciences (NMBU), Ås, Norway
| | - Tina Jeoh
- Biological and Agricultural Engineering, University of California, Davis, United States
| | - Svein J Horn
- Faculty of Chemistry, Biotechnology, and Food Science, Norwegian University of Life Sciences (NMBU), Ås, Norway.
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9
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Kuo MT, Raffaelle JF, Waller EM, Varaljay VA, Wagner D, Kelley-Loughnane N, Reuel NF. Screening Enzymatic Degradation of Polyester Polyurethane with Fluorescent Single-walled Carbon Nanotube and Polymer Nanoparticle Conjugates. ACS NANO 2023; 17:17021-17030. [PMID: 37606935 DOI: 10.1021/acsnano.3c04347] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/23/2023]
Abstract
Enzymatic biodegradation is a promising method to reclaim plastic materials. However, to date, a high-throughput method for screening potential enzyme candidates for biodegradation is still lacking. Here, we propose a single-walled carbon nanotube (SWCNT) fluorescence sensor for screening the enzymatic degradation of polyester polyurethane nanoparticles. Through wrapping the SWCNT with cationic chitosan, an electrostatic bond is formed between the SWCNT and Impranil, a widely applied model substrate of polyester polyurethane. As Impranil is being degraded by the enzymes, a characteristic quenching at a short reaction time followed by a brightening at a longer reaction time in the fluorescence signal is observed. The time-dependent fluorescence response is compared with turbidity measurement, and we conclude that the brightening in fluorescence results from the binding of the degradation product with the SWCNT. The proposed SWCNT sensor design has the potential to screen enzyme candidates for selective degradation of other plastic particles.
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Affiliation(s)
- Mei-Tsan Kuo
- Department of Chemical and Biological Engineering, Iowa State University, Ames, Iowa 50011, United States
| | - Jack F Raffaelle
- Department of Chemical and Biological Engineering, Iowa State University, Ames, Iowa 50011, United States
| | - Ellise McKenna Waller
- Department of Chemical and Biological Engineering, Iowa State University, Ames, Iowa 50011, United States
| | - Vanessa A Varaljay
- Materials and Manufacturing Directorate, Air Force Research Laboratory, Wright-Patterson AFB, Dayton, Ohio 45433, United States
| | | | - Nancy Kelley-Loughnane
- Materials and Manufacturing Directorate, Air Force Research Laboratory, Wright-Patterson AFB, Dayton, Ohio 45433, United States
| | - Nigel F Reuel
- Department of Chemical and Biological Engineering, Iowa State University, Ames, Iowa 50011, United States
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10
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Roveri A, Di Giacinto F, Rossetto M, Cozza G, Cheng Q, Miotto G, Zennaro L, Di Paolo ML, Arnér ESJ, De Spirito M, Maiorino M, Ursini F. Cardiolipin drives the catalytic activity of GPX4 on membranes: Insights from the R152H mutant. Redox Biol 2023; 64:102806. [PMID: 37413766 DOI: 10.1016/j.redox.2023.102806] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2023] [Revised: 06/28/2023] [Accepted: 06/30/2023] [Indexed: 07/08/2023] Open
Abstract
The aim of this study was to examine, in biochemical detail, the functional role of the Arg152 residue in the selenoprotein Glutathione Peroxidase 4 (GPX4), whose mutation to His is involved in Sedaghatian-type Spondylometaphyseal Dysplasia (SSMD). Wild-type and mutated recombinant enzymes with selenopcysteine (Sec) at the active site, were purified and structurally characterized to investigate the impact of the R152H mutation on enzymatic function. The mutation did not affect the peroxidase reaction's catalytic mechanism, and the kinetic parameters were qualitatively similar between the wild-type enzyme and the mutant when mixed micelles and monolamellar liposomes containing phosphatidylcholine and its hydroperoxide derivatives were used as substrate. However, in monolamellar liposomes also containing cardiolipin, which binds to a cationic area near the active site of GPX4, including residue R152, the wild-type enzyme showed a non-canonical dependency of the reaction rate on the concentration of both enzyme and membrane cardiolipin. To explain this oddity, a minimal model was developed encompassing the kinetics of both the enzyme interaction with the membrane and the catalytic peroxidase reaction. Computational fitting of experimental activity recordings showed that the wild-type enzyme was surface-sensing and prone to "positive feedback" in the presence of cardiolipin, indicating a positive cooperativity. This feature was minimal, if any, in the mutant. These findings suggest that GPX4 physiology in cardiolipin containing mitochondria is unique, and emerges as a likely target of the pathological dysfunction in SSMD.
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Affiliation(s)
| | - Flavio Di Giacinto
- Neuroscience Department, Biophysics Section, Università Cattolica del Sacro Cuore, Rome, Italy
| | - Monica Rossetto
- Department of Molecular Medicine, University of Padova, Italy
| | - Giorgio Cozza
- Department of Molecular Medicine, University of Padova, Italy
| | - Qing Cheng
- Division of Biochemistry, Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Stockholm, 17177, Sweden
| | - Giovanni Miotto
- Department of Molecular Medicine, University of Padova, Italy
| | - Lucio Zennaro
- Department of Molecular Medicine, University of Padova, Italy
| | | | - Elias S J Arnér
- Division of Biochemistry, Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Stockholm, 17177, Sweden; Department of Selenoprotein Research and the National Tumor Biology Laboratory, National Institute of Oncology, Budapest, Hungary
| | - Marco De Spirito
- Neuroscience Department, Biophysics Section, Università Cattolica del Sacro Cuore, Rome, Italy
| | | | - Fulvio Ursini
- Department of Molecular Medicine, University of Padova, Italy.
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11
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Tian Y, Wang Y, Liu X, Herburger K, Westh P, Møller MS, Svensson B, Zhong Y, Blennow A. Interfacial enzyme kinetics reveals degradation mechanisms behind resistant starch. Food Hydrocoll 2023. [DOI: 10.1016/j.foodhyd.2023.108621] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/04/2023]
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12
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Tian Y, Wang Y, Zhong Y, Møller MS, Westh P, Svensson B, Blennow A. Interfacial Catalysis during Amylolytic Degradation of Starch Granules: Current Understanding and Kinetic Approaches. Molecules 2023; 28:molecules28093799. [PMID: 37175208 PMCID: PMC10180094 DOI: 10.3390/molecules28093799] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2023] [Revised: 04/20/2023] [Accepted: 04/25/2023] [Indexed: 05/15/2023] Open
Abstract
Enzymatic hydrolysis of starch granules forms the fundamental basis of how nature degrades starch in plant cells, how starch is utilized as an energy resource in foods, and develops efficient, low-cost saccharification of starch, such as bioethanol and sweeteners. However, most investigations on starch hydrolysis have focused on its rates of degradation, either in its gelatinized or soluble state. These systems are inherently more well-defined, and kinetic parameters can be readily derived for different hydrolytic enzymes and starch molecular structures. Conversely, hydrolysis is notably slower for solid substrates, such as starch granules, and the kinetics are more complex. The main problems include that the surface of the substrate is multifaceted, its chemical and physical properties are ill-defined, and it also continuously changes as the hydrolysis proceeds. Hence, methods need to be developed for analyzing such heterogeneous catalytic systems. Most data on starch granule degradation are obtained on a long-term enzyme-action basis from which initial rates cannot be derived. In this review, we discuss these various aspects and future possibilities for developing experimental procedures to describe and understand interfacial enzyme hydrolysis of native starch granules more accurately.
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Affiliation(s)
- Yu Tian
- Department of Plant and Environmental Sciences, University of Copenhagen, DK-1871 Frederiksberg C, Denmark
| | - Yu Wang
- Enzyme and Protein Chemistry, Department of Biotechnology and Biomedicine, Technical University of Denmark, DK-2800 Kongens Lyngby, Denmark
| | - Yuyue Zhong
- Department of Plant and Environmental Sciences, University of Copenhagen, DK-1871 Frederiksberg C, Denmark
| | - Marie Sofie Møller
- Applied Molecular Enzyme Chemistry, Department of Biotechnology and Biomedicine, Technical University of Denmark, DK-2800 Kongens Lyngby, Denmark
| | - Peter Westh
- Interfacial Enzymology, Department of Biotechnology and Biomedicine, Technical University of Denmark, DK-2800 Kongens Lyngby, Denmark
| | - Birte Svensson
- Enzyme and Protein Chemistry, Department of Biotechnology and Biomedicine, Technical University of Denmark, DK-2800 Kongens Lyngby, Denmark
| | - Andreas Blennow
- Department of Plant and Environmental Sciences, University of Copenhagen, DK-1871 Frederiksberg C, Denmark
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13
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Avilan L, Lichtenstein BR, König G, Zahn M, Allen MD, Oliveira L, Clark M, Bemmer V, Graham R, Austin HP, Dominick G, Johnson CW, Beckham GT, McGeehan JE, Pickford AR. Concentration-Dependent Inhibition of Mesophilic PETases on Poly(ethylene terephthalate) Can Be Eliminated by Enzyme Engineering. CHEMSUSCHEM 2023; 16:e202202277. [PMID: 36811288 DOI: 10.1002/cssc.202202277] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/07/2022] [Revised: 02/17/2023] [Indexed: 06/18/2023]
Abstract
Enzyme-based depolymerization is a viable approach for recycling of poly(ethylene terephthalate) (PET). PETase from Ideonella sakaiensis (IsPETase) is capable of PET hydrolysis under mild conditions but suffers from concentration-dependent inhibition. In this study, this inhibition is found to be dependent on incubation time, the solution conditions, and PET surface area. Furthermore, this inhibition is evident in other mesophilic PET-degrading enzymes to varying degrees, independent of the level of PET depolymerization activity. The inhibition has no clear structural basis, but moderately thermostable IsPETase variants exhibit reduced inhibition, and the property is completely absent in the highly thermostable HotPETase, previously engineered by directed evolution, which simulations suggest results from reduced flexibility around the active site. This work highlights a limitation in applying natural mesophilic hydrolases for PET hydrolysis and reveals an unexpected positive outcome of engineering these enzymes for enhanced thermostability.
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Affiliation(s)
- Luisana Avilan
- Centre for Enzyme Innovation, School of Biological Sciences, Institute of Biological and Biomedical Sciences, University of Portsmouth, Portsmouth, PO1 2DY, United Kingdom
- BOTTLE Consortium, Golden, CO 80401, United States
| | - Bruce R Lichtenstein
- Centre for Enzyme Innovation, School of Biological Sciences, Institute of Biological and Biomedical Sciences, University of Portsmouth, Portsmouth, PO1 2DY, United Kingdom
- BOTTLE Consortium, Golden, CO 80401, United States
| | - Gerhard König
- Centre for Enzyme Innovation, School of Biological Sciences, Institute of Biological and Biomedical Sciences, University of Portsmouth, Portsmouth, PO1 2DY, United Kingdom
- BOTTLE Consortium, Golden, CO 80401, United States
| | - Michael Zahn
- Centre for Enzyme Innovation, School of Biological Sciences, Institute of Biological and Biomedical Sciences, University of Portsmouth, Portsmouth, PO1 2DY, United Kingdom
- BOTTLE Consortium, Golden, CO 80401, United States
| | - Mark D Allen
- Centre for Enzyme Innovation, School of Biological Sciences, Institute of Biological and Biomedical Sciences, University of Portsmouth, Portsmouth, PO1 2DY, United Kingdom
- BOTTLE Consortium, Golden, CO 80401, United States
| | - Liliana Oliveira
- Centre for Enzyme Innovation, School of Biological Sciences, Institute of Biological and Biomedical Sciences, University of Portsmouth, Portsmouth, PO1 2DY, United Kingdom
- BOTTLE Consortium, Golden, CO 80401, United States
| | - Matilda Clark
- Centre for Enzyme Innovation, School of Biological Sciences, Institute of Biological and Biomedical Sciences, University of Portsmouth, Portsmouth, PO1 2DY, United Kingdom
- BOTTLE Consortium, Golden, CO 80401, United States
| | - Victoria Bemmer
- Centre for Enzyme Innovation, School of Biological Sciences, Institute of Biological and Biomedical Sciences, University of Portsmouth, Portsmouth, PO1 2DY, United Kingdom
- BOTTLE Consortium, Golden, CO 80401, United States
| | - Rosie Graham
- Centre for Enzyme Innovation, School of Biological Sciences, Institute of Biological and Biomedical Sciences, University of Portsmouth, Portsmouth, PO1 2DY, United Kingdom
- BOTTLE Consortium, Golden, CO 80401, United States
| | - Harry P Austin
- Institute of Biochemistry, Department of Biotechnology & Enzyme Catalysis, University of Greifswald, D-17487, Greifswald, Germany
| | - Graham Dominick
- Renewable Resources and Enabling Sciences Center, National Renewable Energy Laboratory, Golden, CO, 80401, United States
| | - Christopher W Johnson
- Renewable Resources and Enabling Sciences Center, National Renewable Energy Laboratory, Golden, CO, 80401, United States
| | - Gregg T Beckham
- BOTTLE Consortium, Golden, CO 80401, United States
- Renewable Resources and Enabling Sciences Center, National Renewable Energy Laboratory, Golden, CO, 80401, United States
| | - John E McGeehan
- Centre for Enzyme Innovation, School of Biological Sciences, Institute of Biological and Biomedical Sciences, University of Portsmouth, Portsmouth, PO1 2DY, United Kingdom
- BOTTLE Consortium, Golden, CO 80401, United States
| | - Andrew R Pickford
- Centre for Enzyme Innovation, School of Biological Sciences, Institute of Biological and Biomedical Sciences, University of Portsmouth, Portsmouth, PO1 2DY, United Kingdom
- BOTTLE Consortium, Golden, CO 80401, United States
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14
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Richter PK, Blázquez-Sánchez P, Zhao Z, Engelberger F, Wiebeler C, Künze G, Frank R, Krinke D, Frezzotti E, Lihanova Y, Falkenstein P, Matysik J, Zimmermann W, Sträter N, Sonnendecker C. Structure and function of the metagenomic plastic-degrading polyester hydrolase PHL7 bound to its product. Nat Commun 2023; 14:1905. [PMID: 37019924 PMCID: PMC10076380 DOI: 10.1038/s41467-023-37415-x] [Citation(s) in RCA: 11] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2022] [Accepted: 03/16/2023] [Indexed: 04/07/2023] Open
Abstract
The recently discovered metagenomic-derived polyester hydrolase PHL7 is able to efficiently degrade amorphous polyethylene terephthalate (PET) in post-consumer plastic waste. We present the cocrystal structure of this hydrolase with its hydrolysis product terephthalic acid and elucidate the influence of 17 single mutations on the PET-hydrolytic activity and thermal stability of PHL7. The substrate-binding mode of terephthalic acid is similar to that of the thermophilic polyester hydrolase LCC and deviates from the mesophilic IsPETase. The subsite I modifications L93F and Q95Y, derived from LCC, increased the thermal stability, while exchange of H185S, derived from IsPETase, reduced the stability of PHL7. The subsite II residue H130 is suggested to represent an adaptation for high thermal stability, whereas L210 emerged as the main contributor to the observed high PET-hydrolytic activity. Variant L210T showed significantly higher activity, achieving a degradation rate of 20 µm h-1 with amorphous PET films.
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Affiliation(s)
- P Konstantin Richter
- Institute of Bioanalytical Chemistry, Centre for Biotechnology and Biomedicine, Leipzig University, Leipzig, Germany
| | | | - Ziyue Zhao
- Institute of Analytical Chemistry, Leipzig University, Leipzig, Germany
| | - Felipe Engelberger
- Institute for Drug Discovery, Leipzig University Medical School, Leipzig, Germany
| | - Christian Wiebeler
- Institute of Analytical Chemistry, Leipzig University, Leipzig, Germany
- Wilhelm-Ostwald-Institute for Physical and Theoretical Chemistry, Leipzig University, Leipzig, Germany
| | - Georg Künze
- Institute for Drug Discovery, Leipzig University Medical School, Leipzig, Germany
| | - Ronny Frank
- Centre for Biotechnology and Biomedicine, Molecular Biological-Biochemical Processing Technology, Leipzig University, Leipzig, Germany
| | - Dana Krinke
- Centre for Biotechnology and Biomedicine, Molecular Biological-Biochemical Processing Technology, Leipzig University, Leipzig, Germany
| | - Emanuele Frezzotti
- Department of Chemical Life and Environmental Sciences, University of Parma, Parma, Italy
| | - Yuliia Lihanova
- Institute of Analytical Chemistry, Leipzig University, Leipzig, Germany
| | | | - Jörg Matysik
- Institute of Analytical Chemistry, Leipzig University, Leipzig, Germany
| | | | - Norbert Sträter
- Institute of Bioanalytical Chemistry, Centre for Biotechnology and Biomedicine, Leipzig University, Leipzig, Germany.
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15
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Wang F, Liu M, Niu X, Xia L, Qu F. Dextran-assisted ultrasonic exfoliation of two-dimensional metal-organic frameworks to evaluate acetylcholinesterase activity and inhibitor screening. Anal Chim Acta 2023; 1243:340815. [PMID: 36697184 DOI: 10.1016/j.aca.2023.340815] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2022] [Revised: 11/28/2022] [Accepted: 01/08/2023] [Indexed: 01/12/2023]
Abstract
Acetylcholinesterase (AChE) is regarded as a biomarker of Alzheimer's disease (AD), and its inhibitors show great potential in AD therapy as AChE can increase the neurotoxicity of the amyloid component that induces AD. Because of this, it is crucial and significant to develop a simple and highly sensitive strategy to monitor AChE levels and screen highly efficient AChE inhibitors. Herein, we synthesize an ultrathin two-dimensional (2D) metal-organic framework (MOF) based on copper-catecholate (Cu-CAT) via dextran assisted ultrasound exfoliation, followed by construction of a sensitive sensor for the monitoring AChE and screening of its inhibitors. By adding AChE, the acetylthiocholine (ATCh) substrate is hydrolyzed to be thiocholine (TCh), which decreases the peroxidase-like activity of Cu-CAT nanosheets (Cu-CAT NSs), impairing the signal reaction of 3,3',5,5'-tetramethylbenzidine (TMB) to oxidized-TMB (ox-TMB). In the presence of an AChE inhibitor, the signal can be gradually restored. The newly developed sensor shows high sensitivity and selectivity for AChE and huperzine A (HA, an effective drug for AD, an acetylcholine receptor antagonist), as well as for AD drug discovery from traditional Chinese herbs. The limit of detection of the sensor for AChE is 0.01 mU mL-1 and the average IC50 value of HA is 30.81 nM under the optimal of catalysis conditions. Compared with the 3D bulk Cu-CAT, the current 2D Cu-CAT NSs exhibit higher peroxidase activity due to more catalytic active site exposure. This study provides a strategy to prepare an ultrathin 2D MOF with high catalytic activity and new insights for the construction of a biosensor to monitor AChE and new AD drugs.
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Affiliation(s)
- Fang Wang
- College of Chemistry and Chemical Engineering, Qufu Normal University, Qufu, 273165, Shandong, China
| | - Mingxue Liu
- College of Chemistry and Chemical Engineering, Qufu Normal University, Qufu, 273165, Shandong, China
| | - Xiankang Niu
- College of Chemistry and Chemical Engineering, Qufu Normal University, Qufu, 273165, Shandong, China
| | - Lian Xia
- College of Chemistry and Chemical Engineering, Qufu Normal University, Qufu, 273165, Shandong, China.
| | - Fengli Qu
- College of Chemistry and Chemical Engineering, Qufu Normal University, Qufu, 273165, Shandong, China.
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16
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Hernández A. Mathematical expressions describing enzyme velocity and inhibition at high enzyme concentration. Biol Chem 2023; 404:15-27. [PMID: 36165810 DOI: 10.1515/hsz-2022-0163] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2022] [Accepted: 08/18/2022] [Indexed: 12/14/2022]
Abstract
Enzyme behaviour is characterised in the laboratory using diluted solutions of enzyme. However, in vivo processes usually occur at [S T ] ≈ [E T ] ≈ K m . Furthermore, the study of enzyme action involves characterisation of inhibitors and their mechanisms. However, to date, there have been no reports proposing mathematical expressions that can be used to describe enzyme activity at high enzyme concentration apart from the simplest single substrate, irreversible case. Using a continued fraction approach, equations can be easily derived for the most common cases in monosubstrate reactions, such as irreversible or reversible reactions and effector (inhibitor or activator) kinetic interactions. These expressions are an extension of the classical Michaelis-Menten equations. A first analysis using these expressions permits to deduce some differences at high versus low enzyme concentration, such as the greater effectiveness of allosteric inhibitors compared to catalytic ones. Also, they can be used to understand catalyst saturation in a reaction. Although they can be linearised, these equations also show differences that need to be taken into account. For example, the different meaning of line intersection points in Dixon plots. All in all, these expressions may be useful tools for modelling in vivo and biotechnological processes.
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Affiliation(s)
- Agustín Hernández
- Unit for Integrated Research on Tropical Biodiversity - BIOTROP, Centre for Biological and Health Sciences, Federal University of Sao Carlos, Sao Carlos (SP), Brazil
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17
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Li Q, Liu W, Jing N, Li Q, Yang K, Wang X, Yao J. Attack Site Density of a Highly-efficient PET Hydrolases. Protein Pept Lett 2023; 30:506-512. [PMID: 37165591 DOI: 10.2174/0929866530666230509141807] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2022] [Revised: 03/07/2023] [Accepted: 04/04/2023] [Indexed: 05/12/2023]
Abstract
INTRODUCTION Poly (ethylene terephthalate) (PET) is one of the most abundant polyester materials used in daily life and it is also one of the main culprits of environmental pollution. ICCG (F243I/D238C/S283C/Y127G) is an enzyme that performs four modifications on the leaf branch compost keratase (LCC). It shows excellent performance in the hydrolysis of PET and has a great potential in further applications. METHOD Here, we used ICCG to degrade PET particles of various sizes and use the density of attack sites (Γattack) and kinetic parameters to evaluate the effect of particle size on enzyme degradation efficiency. We are surprised to observe that there is a certain relationship between Km and Γattack. In order to further confirm the relationship, we obtained three different enzymes (Y95K, M166S and H218S) by site-directed mutagenesis on the basis of ICCG. RESULT The results confirmed that there was a negative correlation between Km and Γattack. In addition, we also found that increasing the affinity between the enzyme and the substrate does not necessarily lead to the increase of degradation rate. CONCLUSION These findings show that the granulation of PET and the selection of appropriate particle size are helpful to improve its industrial application value. At the same time, additional protein engineering to increase ICCG performance is realistic, but it can't be limited to enhance the affinity between enzyme and substrate.
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Affiliation(s)
- Qiang Li
- School of Biological Science and Technology, University of Jinan, Jinan, 250022, China
| | - Wenhong Liu
- School of Biological Science and Technology, University of Jinan, Jinan, 250022, China
| | - Nannan Jing
- School of Biological Science and Technology, University of Jinan, Jinan, 250022, China
| | - Qingqing Li
- School of Biological Science and Technology, University of Jinan, Jinan, 250022, China
| | - Kang Yang
- School of Biological Science and Technology, University of Jinan, Jinan, 250022, China
| | - Xia Wang
- School of Biological Science and Technology, University of Jinan, Jinan, 250022, China
| | - Jianzhuang Yao
- School of Biological Science and Technology, University of Jinan, Jinan, 250022, China
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18
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A new continuous assay for quantitative assessment of enzymatic degradation of poly(ethylene terephthalate) (PET). Enzyme Microb Technol 2023; 162:110142. [DOI: 10.1016/j.enzmictec.2022.110142] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2022] [Revised: 10/01/2022] [Accepted: 10/12/2022] [Indexed: 11/06/2022]
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19
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Sun C, Meng X, Sun F, Zhang J, Tu M, Chang JS, Reungsang A, Xia A, Ragauskas AJ. Advances and perspectives on mass transfer and enzymatic hydrolysis in the enzyme-mediated lignocellulosic biorefinery: A review. Biotechnol Adv 2023; 62:108059. [PMID: 36402253 DOI: 10.1016/j.biotechadv.2022.108059] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2022] [Revised: 11/04/2022] [Accepted: 11/13/2022] [Indexed: 11/18/2022]
Abstract
Enzymatic hydrolysis is a critical process for the cellulase-mediated lignocellulosic biorefinery to produce sugar syrups that can be converted into a whole range of biofuels and biochemicals. Such a process operating at high-solid loadings (i.e., scarcely any free water or roughly ≥ 15% solids, w/w) is considered more economically feasible, as it can generate a high sugar concentration at low operation and capital costs. However, this approach remains restricted and incurs "high-solid effects", ultimately causing the lower hydrolysis yields with increasing solid loadings. The lack of available water leads to a highly viscous system with impaired mixing that exhibits strong transfer resistance and reaction limitation imposed on enzyme action. Evidently, high-solid enzymatic hydrolysis involves multi-scale mass transfer and multi-phase enzyme reaction, and thus requires a synergistic perspective of transfer and biotransformation to assess the interactions among water, biomass components, and cellulase enzymes. Porous particle characteristics of biomass and its interface properties determine the water form and distribution state surrounding the particles, which are summarized in this review aiming to identify the water-driven multi-scale/multi-phase bioprocesses. Further aided by the cognition of rheological behavior of biomass slurry, solute transfer theories, and enzyme kinetics, the coupling effects of flow-transfer-reaction are revealed under high-solid conditions. Based on the above basic features, this review lucidly explains the causes of high-solid hydrolysis hindrances, highlights the mismatched issues between transfer and reaction, and more importantly, presents the advanced strategies for transfer and reaction enhancements from the viewpoint of process optimization, reactor design, as well as enzyme/auxiliary additive customization.
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Affiliation(s)
- Chihe Sun
- Key Laboratory of Industrial Biotechnology of MOE, School of Biotechnology, Jiangnan University, Wuxi 214122, China
| | - Xianzhi Meng
- Department of Chemical & Biomolecular Engineering, University of Tennessee, Knoxville, TN 37996, USA
| | - Fubao Sun
- Key Laboratory of Industrial Biotechnology of MOE, School of Biotechnology, Jiangnan University, Wuxi 214122, China.
| | - Junhua Zhang
- Jiangsu Co-Innovation Center of Efficient Processing and Utilization of Forest Resources, College of Chemical Engineering, Nanjing Forestry University, 159 Longpan Road, Nanjing 210037, China
| | - Maobing Tu
- Department of Chemical and Environmental Engineering, University of Cincinnati, Cincinnati, OH 45221, USA
| | - Jo-Shu Chang
- Department of Chemical and Materials Engineering, Tunghai University, Taichung 407, Taiwan
| | - Alissara Reungsang
- Department of Biotechnology, Faculty of Technology, Khon Kaen University, Khon Kaen 40002, Thailand
| | - Ao Xia
- Key Laboratory of Low-grade Energy Utilization Technologies and Systems, Chongqing University, Ministry of Education, Chongqing 400044, China
| | - Arthur J Ragauskas
- Department of Chemical & Biomolecular Engineering, University of Tennessee, Knoxville, TN 37996, USA; Center for Renewable Carbon, Department of Forestry, Wildlife and Fisheries, The University of Tennessee, Knoxville, TN 37996, USA; Joint Institute of Biological Sciences, Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA.
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20
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Calloni RD, Muchut RJ, Garay AS, Arias DG, Iglesias AA, Guerrero SA. Functional and structural characterization of an endo-β-1,3-glucanase from Euglena gracilis. Biochimie 2022; 208:117-128. [PMID: 36586565 DOI: 10.1016/j.biochi.2022.12.016] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2022] [Revised: 12/20/2022] [Accepted: 12/23/2022] [Indexed: 12/29/2022]
Abstract
Endo-β-1,3-glucanases from several organisms have attracted much attention in recent years because of their capability for in vitro degrading β-1,3-glucan as a critical step for both biofuels production and short-chain oligosaccharides synthesis. In this study, we biochemically characterized a putative endo-β-1,3-glucanase (EgrGH64) belonging to the family GH64 from the single-cell protist Euglena gracilis. The gene coding for the enzyme was heterologously expressed in a prokaryotic expression system supplemented with 3% (v/v) ethanol to optimize the recombinant protein right folding. Thus, the produced enzyme was highly purified by immobilized-metal affinity and gel filtration chromatography. The enzymatic study demonstrated that EgrGH64 could hydrolyze laminarin (KM 23.5 mg ml-1,kcat 1.20 s-1) and also, but with less enzymatic efficiency, paramylon (KM 20.2 mg ml-1,kcat 0.23 ml mg-1 s-1). The major product of the hydrolysis of both substrates was laminaripentaose. The enzyme could also use ramified β-glucan from the baker's yeast cell wall as a substrate (KM 2.10 mg ml-1, kcat 0.88 ml mg-1 s-1). This latter result, combined with interfacial kinetic analysis evidenced a protein's greater efficiency for the yeast polysaccharide, and a higher number of hydrolysis sites in the β-1,3/β-1,6-glucan. Concurrently, the enzyme efficiently inhibited the fungal growth when used at 1.0 mg/mL (15.4 μM). This study contributes to assigning a correct function and determining the enzymatic specificity of EgrGH64, which emerges as a relevant biotechnological tool for processing β-glucans.
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Affiliation(s)
- Rodrigo D Calloni
- Laboratorio de Enzimología Molecular, Instituto de Agrobiotecnología del Litoral (CONICET-UNL), Santa Fe, Argentina; Facultad de Bioquímica y Ciencias Biológicas, Universidad Nacional del Litoral, Santa Fe, Argentina
| | - Robertino J Muchut
- Laboratorio de Enzimología Molecular, Instituto de Agrobiotecnología del Litoral (CONICET-UNL), Santa Fe, Argentina
| | - Alberto S Garay
- Facultad de Bioquímica y Ciencias Biológicas, Universidad Nacional del Litoral, Santa Fe, Argentina
| | - Diego G Arias
- Laboratorio de Enzimología Molecular, Instituto de Agrobiotecnología del Litoral (CONICET-UNL), Santa Fe, Argentina; Facultad de Bioquímica y Ciencias Biológicas, Universidad Nacional del Litoral, Santa Fe, Argentina
| | - Alberto A Iglesias
- Laboratorio de Enzimología Molecular, Instituto de Agrobiotecnología del Litoral (CONICET-UNL), Santa Fe, Argentina; Facultad de Bioquímica y Ciencias Biológicas, Universidad Nacional del Litoral, Santa Fe, Argentina
| | - Sergio A Guerrero
- Laboratorio de Enzimología Molecular, Instituto de Agrobiotecnología del Litoral (CONICET-UNL), Santa Fe, Argentina; Facultad de Bioquímica y Ciencias Biológicas, Universidad Nacional del Litoral, Santa Fe, Argentina.
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21
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Petrášek Z, Nidetzky B. Model of Processive Catalysis with Site Clustering and Blocking and Its Application to Cellulose Hydrolysis. J Phys Chem B 2022; 126:8472-8485. [PMID: 36251767 PMCID: PMC9623590 DOI: 10.1021/acs.jpcb.2c05956] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
Interactions between particles moving on a linear track and their possible blocking by obstacles can lead to crowding, impeding the particles' transport kinetics. When the particles are enzymes processively catalyzing a reaction along a linear polymeric substrate, these crowding and blocking effects may substantially reduce the overall catalytic rate. Cellulose hydrolysis by exocellulases processively moving along cellulose chains assembled into insoluble cellulose particles is an example of such a catalytic transport process. The details of the kinetics of cellulose hydrolysis and the causes of the often observed reduction of hydrolysis rate over time are not yet fully understood. Crowding and blocking of enzyme particles are thought to be one of the important factors affecting the cellulose hydrolysis, but its exact role and mechanism are not clear. Here, we introduce a simple model based on an elementary transport process that incorporates the crowding and blocking effects in a straightforward way. This is achieved by making a distinction between binding and non-binding sites on the chain. The model reproduces a range of experimental results, mainly related to the early phase of cellulose hydrolysis. Our results indicate that the combined effects of clustering of binding sites together with the occupancy pattern of these sites by the enzyme molecules play a decisive role in the overall kinetics of cellulose hydrolysis. It is suggested that periodic desorption and rebinding of enzyme molecules could be a basis of a strategy to partially counter the clustering of and blocking by the binding sites and so enhance the rate of cellulose hydrolysis. The general nature of the model means that it could be applicable also to other transport processes that make a distinction between binding and non-binding sites, where crowding and blocking are expected to be relevant.
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Affiliation(s)
- Zdeněk Petrášek
- Institute
of Biotechnology and Biochemical Engineering, Graz University of Technology, NAWI Graz, Petersgasse 12, A-8010Graz, Austria,
| | - Bernd Nidetzky
- Institute
of Biotechnology and Biochemical Engineering, Graz University of Technology, NAWI Graz, Petersgasse 12, A-8010Graz, Austria,Austrian
Centre of Industrial Biotechnology, Petersgasse 14, A-8010Graz, Austria,. Phone: +43 (0)316 8738409, +43 (0)316 8738400
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22
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Zurier HS, Goddard JM. Directed Immobilization of PETase on Mesoporous Silica Enables Sustained Depolymerase Activity in Synthetic Wastewater Conditions. ACS APPLIED BIO MATERIALS 2022; 5:4981-4992. [PMID: 36194455 DOI: 10.1021/acsabm.2c00700] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Microplastic accumulation in terrestrial and aquatic environments is a growing environmental challenge. Biodegradation has shown promise as an intervention strategy for reducing the spread of microplastics. The wastewater treatment system is a key intervention point in microplastic biodegradation due to its pivotal role in the water cycle at the interface between human activity and the environmental. However, the best characterized microplastic degradation enzyme, PETase, lacks the stability to perform at scale in wastewater treatment. In this work, we show that genetic fusion of PETase to a silica binding peptide enables directed immobilization of the enzyme onto silica nanoparticles. PETase activity in simulated wastewater conditions is quantified by linear regression from time zero to the time of maximum fluorescence of a fluorescent oxidized product of PETase degradation of PET microfibers. Mesoporous silica is shown to be a superior support material to nonporous silica. The resulting biocatalytic nanomaterial has up to 2.5-fold enhanced stability and 6.2-fold increased activity compared to free enzyme in unbuffered, 40 °C simulated influent (ionic strength ∼15 mM). In unbuffered, 40 °C simulated effluent (ionic strength ∼700 μM), reaction velocity and overall catalytic activity were increased by the biocatalytic material 2.1-fold relative to free PETase. All reactions were performed in 0.2 mL volumes, and enzyme concentrations were normalized across both free and immobilized samples to 9 μg/mL. Site-directed mutagenesis is shown to be a complementary technique to directed immobilization, which may aid in optimization of the biomaterial for wastewater applications. PETase stabilization in application-relevant environments as shown here enables progress toward application of PETase for microplastic biodegradation in wastewater treatment.
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Affiliation(s)
- Hannah S Zurier
- Department of Food Science and Technology, Cornell University, Ithaca, New York14853, United States
| | - Julie M Goddard
- Department of Food Science and Technology, Cornell University, Ithaca, New York14853, United States
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23
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Eiamthong B, Meesawat P, Wongsatit T, Jitdee J, Sangsri R, Patchsung M, Aphicho K, Suraritdechachai S, Huguenin-Dezot N, Tang S, Suginta W, Paosawatyanyong B, Babu MM, Chin JW, Pakotiprapha D, Bhanthumnavin W, Uttamapinant C. Discovery and Genetic Code Expansion of a Polyethylene Terephthalate (PET) Hydrolase from the Human Saliva Metagenome for the Degradation and Bio-Functionalization of PET. Angew Chem Int Ed Engl 2022; 61:e202203061. [PMID: 35656865 PMCID: PMC7613822 DOI: 10.1002/anie.202203061] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2022] [Indexed: 11/24/2022]
Abstract
We report a bioinformatic workflow and subsequent discovery of a new polyethylene terephthalate (PET) hydrolase, which we named MG8, from the human saliva metagenome. MG8 has robust PET plastic degradation activities under different temperature and salinity conditions, outperforming several naturally occurring and engineered hydrolases in degrading PET. Moreover, we genetically encoded 2,3-diaminopropionic acid (DAP) in place of the catalytic serine residue of MG8, thereby converting a PET hydrolase into a covalent binder for bio-functionalization of PET. We show that MG8(DAP), in conjunction with a split green fluorescent protein system, can be used to attach protein cargos to PET as well as other polyester plastics. The discovery of a highly active PET hydrolase from the human metagenome-currently an underexplored resource for industrial enzyme discovery-as well as the repurposing of such an enzyme into a plastic functionalization tool, should facilitate ongoing efforts to degrade and maximize reusability of PET.
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Affiliation(s)
- Bhumrapee Eiamthong
- School of Biomolecular Science and Engineering, Vidyasirimedhi Institute of Science and Technology (VISTEC), Rayong, 21210, Thailand
| | - Piyachat Meesawat
- School of Biomolecular Science and Engineering, Vidyasirimedhi Institute of Science and Technology (VISTEC), Rayong, 21210, Thailand
| | - Thanakrit Wongsatit
- School of Biomolecular Science and Engineering, Vidyasirimedhi Institute of Science and Technology (VISTEC), Rayong, 21210, Thailand
| | - Jariya Jitdee
- Department of Chemistry, Faculty of Science, Chulalongkorn University, Bangkok, 10330, Thailand
| | - Raweewan Sangsri
- Department of Biochemistry and Center for Excellence in Protein and Enzyme Technology, Faculty of Science, Mahidol University, Bangkok, 10400, Thailand
| | - Maturada Patchsung
- School of Biomolecular Science and Engineering, Vidyasirimedhi Institute of Science and Technology (VISTEC), Rayong, 21210, Thailand
| | - Kanokpol Aphicho
- School of Biomolecular Science and Engineering, Vidyasirimedhi Institute of Science and Technology (VISTEC), Rayong, 21210, Thailand
| | - Surased Suraritdechachai
- School of Biomolecular Science and Engineering, Vidyasirimedhi Institute of Science and Technology (VISTEC), Rayong, 21210, Thailand
| | | | - Shan Tang
- Medical Research Council Laboratory of Molecular Biology, Cambridge, CB2 0QH, UK
| | - Wipa Suginta
- School of Biomolecular Science and Engineering, Vidyasirimedhi Institute of Science and Technology (VISTEC), Rayong, 21210, Thailand
| | | | - M Madan Babu
- Department of Structural Biology and Center of Excellence for Data Driven Discovery, St. Jude Children's Research Hospital, Memphis, TN 38105, USA
| | - Jason W Chin
- Medical Research Council Laboratory of Molecular Biology, Cambridge, CB2 0QH, UK
| | - Danaya Pakotiprapha
- Department of Biochemistry and Center for Excellence in Protein and Enzyme Technology, Faculty of Science, Mahidol University, Bangkok, 10400, Thailand
| | - Worawan Bhanthumnavin
- Department of Chemistry, Faculty of Science, Chulalongkorn University, Bangkok, 10330, Thailand
| | - Chayasith Uttamapinant
- School of Biomolecular Science and Engineering, Vidyasirimedhi Institute of Science and Technology (VISTEC), Rayong, 21210, Thailand
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24
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Visible Light-Responsive Sulfone-Based Covalent Organic Framework as Metal-Free Nanoenzyme for Visual Colorimetric Determination of Uranium. CHEMOSENSORS 2022. [DOI: 10.3390/chemosensors10070248] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/10/2022]
Abstract
Covalent organic framework (COF) has been attracting considerable attention as a novel crystalline material owing to its extended π-electron conjugation and excellent spectral behavior. In this study, we present an imine-linked two-dimensional (2D) crystalline sulfone-based covalent organic framework (TAS-COF) synthesized by 2,4,6-triformylphloroglucinol (Tp) and 3,7-diaminodibenzo[b,d]thiophene (DAS) via a Schiff base condensation reaction. The benzothiophene sulfone endows the as-synthesized TAS-COF with excellent oxidase-like activity under visible light irradiation, ascribed to the generation of superoxide radicals (O2•−) by photo-generated electron transfer. TAS-COF can efficiently oxidase the colorless substrate 3,3′,5,5′-tetramethylbenzydine (TMB) into blue oxidized TMB (oxTMB) when exposed to visible light, and the presence of uranium (UO22+) leads to clear color fading due to the coordination between the imine of oxTMB and UO22+. A colorimetric strategy is thus developed for UO22+ determination with a detection limit of 0.07 μmol L−1. Moreover, a paper-based visual sensing platform is also constructed to offer simple and fast UO22+ content evaluation in water samples. The present study not only provides a promising strategy to prepare visible light-triggered COF-based metal-free nanoenzymes but also extends the applications of COF material in radionuclide detection.
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25
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Radkov A, Sapiro AL, Flores S, Henderson C, Saunders H, Kim R, Massa S, Thompson S, Mateusiak C, Biboy J, Zhao Z, Starita LM, Hatleberg WL, Vollmer W, Russell AB, Simorre JP, Anthony-Cahill S, Brzovic P, Hayes B, Chou S. Antibacterial potency of Type VI amidase effector toxins is dependent on substrate topology and cellular context. eLife 2022; 11:79796. [PMID: 35762582 PMCID: PMC9270033 DOI: 10.7554/elife.79796] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2022] [Accepted: 06/23/2022] [Indexed: 11/15/2022] Open
Abstract
Members of the bacterial T6SS amidase effector (Tae) superfamily of toxins are delivered between competing bacteria to degrade cell wall peptidoglycan. Although Taes share a common substrate, they exhibit distinct antimicrobial potency across different competitor species. To investigate the molecular basis governing these differences, we quantitatively defined the functional determinants of Tae1 from Pseudomonas aeruginosa PAO1 using a combination of nuclear magnetic resonance and a high-throughput in vivo genetic approach called deep mutational scanning (DMS). As expected, combined analyses confirmed the role of critical residues near the Tae1 catalytic center. Unexpectedly, DMS revealed substantial contributions to enzymatic activity from a much larger, ring-like functional hot spot extending around the entire circumference of the enzyme. Comparative DMS across distinct growth conditions highlighted how functional contribution of different surfaces is highly context-dependent, varying alongside composition of targeted cell walls. These observations suggest that Tae1 engages with the intact cell wall network through a more distributed three-dimensional interaction interface than previously appreciated, providing an explanation for observed differences in antimicrobial potency across divergent Gram-negative competitors. Further binding studies of several Tae1 variants with their cognate immunity protein demonstrate that requirements to maintain protection from Tae activity may be a significant constraint on the mutational landscape of tae1 toxicity in the wild. In total, our work reveals that Tae diversification has likely been shaped by multiple independent pressures to maintain interactions with binding partners that vary across bacterial species and conditions.
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Affiliation(s)
- Atanas Radkov
- Department of Biochemistry and Biophysics, University of California, San Francisco, San Francisco, United States
| | - Anne L Sapiro
- Department of Biochemistry and Biophysics, University of California, San Francisco, San Francisco, United States
| | | | | | - Hayden Saunders
- Department of Biochemistry and Biophysics, University of California, San Francisco, San Francisco, United States
| | - Rachel Kim
- Pacific Northwest University of Health Sciences, Yakima, United States
| | - Steven Massa
- Department of Biology, Stanford University, Stanford, United States
| | - Samuel Thompson
- Department of Bioengineering, Stanford University, Stanford, United States
| | - Chase Mateusiak
- Computer Science Department, Washington University in St. Louis, St. Louis, United States
| | - Jacob Biboy
- Centre for Bacterial Cell Biology, Newcastle University, Newcastle upon Tyne, United Kingdom
| | - Ziyi Zhao
- Department of Biochemistry and Biophysics, University of California, San Francisco, San Francisco, United States
| | - Lea M Starita
- Department of Genome Sciences, University of Washington, Seattle, United States
| | | | - Waldemar Vollmer
- Center for Bacterial Cell Biology, Newcastle University, Newcastle upon Tyne, United Kingdom
| | - Alistair B Russell
- Division of Biological Sciences, University of California, San Diego, La Jolla, United States
| | - Jean-Pierre Simorre
- Institut de Biologie Structurale, Université Grenoble Alpes, Grenoble, France
| | | | - Peter Brzovic
- Department of Biochemistry, University of Washington, Seattle, United States
| | - Beth Hayes
- Department of Biochemistry and Biophysics, University of California, San Francisco, San Francisco, United States
| | - Seemay Chou
- Department of Biochemistry and Biophysics, University of California, San Francisco, San Francisco, United States
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26
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Eiamthong B, Meesawat P, Wongsatit T, Jitdee J, Sangsri R, Patchsung M, Aphicho K, Suraritdechachai S, Huguenin-Dezot N, Tang S, Suginta W, Paosawatyanyong B, Babu MM, Chin JW, Pakotiprapha D, Bhanthumnavin W, Uttamapinant C. Discovery and Genetic Code Expansion of a Polyethylene Terephthalate (PET) Hydrolase from the Human Saliva Metagenome for the Degradation and Bio‐Functionalization of PET. Angew Chem Int Ed Engl 2022. [DOI: 10.1002/ange.202203061] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Affiliation(s)
- Bhumrapee Eiamthong
- Vidyasirimedhi Institute of Science and Technology School of Biomolecular Science and Engineering THAILAND
| | - Piyachat Meesawat
- Vidyasirimedhi Institute of Science and Technology School of Biomolecular Science and Engineering THAILAND
| | - Thanakrit Wongsatit
- Vidyasirimedhi Institute of Science and Technology School of Biomolecular Science and Engineering THAILAND
| | - Jariya Jitdee
- Chulalongkorn University Faculty of Science Chemistry THAILAND
| | | | - Maturada Patchsung
- Vidyasirimedhi Institute of Science and Technology Biomolecular Science and Engineering THAILAND
| | - Kanokpol Aphicho
- Vidyasirimedhi Institute of Science and Technology Biomolecular Science and Engineering THAILAND
| | - Surased Suraritdechachai
- Vidyasirimedhi Institute of Science and Technology Biomolecular Science and Engineering THAILAND
| | | | - Shan Tang
- MRC Laboratory of Molecular Biology Protein and nucleic acid chemistry UNITED KINGDOM
| | - Wipa Suginta
- Vidyasirimedhi Institute of Science and Technology Biomolecular Science and Engineering THAILAND
| | | | - M. Madan Babu
- St Jude Children's Research Hospital Department of Structural Biology Structural Biology UNITED STATES
| | - Jason W Chin
- MRC Laboratory of Molecular Biology Protein and nucleic acid chemistry UNITED KINGDOM
| | | | | | - Chayasith Uttamapinant
- Vidyasirimedhi Institute of Science and Technology School of Biomolecular Science and Engineering 555 Moo 1 PayupnaiWangchan Valley 21210 Rayong THAILAND
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27
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Arnling Bååth J, Jensen K, Borch K, Westh P, Kari J. Sabatier Principle for Rationalizing Enzymatic Hydrolysis of a Synthetic Polyester. JACS AU 2022; 2:1223-1231. [PMID: 35647598 PMCID: PMC9131473 DOI: 10.1021/jacsau.2c00204] [Citation(s) in RCA: 21] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/31/2022] [Revised: 04/27/2022] [Accepted: 04/27/2022] [Indexed: 05/04/2023]
Abstract
Interfacial enzyme reactions are common in Nature and in industrial settings, including the enzymatic deconstruction of poly(ethylene terephthalate) (PET) waste. Kinetic descriptions of PET hydrolases are necessary for both comparative analyses, discussions of structure-function relations and rational optimization of technical processes. We investigated whether the Sabatier principle could be used for this purpose. Specifically, we compared the kinetics of two well-known PET hydrolases, leaf-branch compost cutinase (LCC) and a cutinase from the bacterium Thermobifida fusca (TfC), when adding different concentrations of the surfactant cetyltrimethylammonium bromide (CTAB). We found that CTAB consistently lowered the strength of enzyme-PET interactions, while its effect on enzymatic turnover was strongly biphasic. Thus, at gradually increasing CTAB concentrations, turnover was initially promoted and subsequently suppressed. This correlation with maximal turnover at an intermediate binding strength was in accordance with the Sabatier principle. One consequence of these results was that both enzymes had too strong intrinsic interaction with PET for optimal turnover, especially TfC, which showed a 20-fold improvement of k cat at the maximum. LCC on the other hand had an intrinsic substrate affinity closer to the Sabatier optimum, and the turnover rate was 5-fold improved at weakened substrate binding. Our results showed that the Sabatier principle may indeed rationalize enzymatic PET degradation and support process optimization. Finally, we suggest that future discovery efforts should consider enzymes with weakened substrate binding because strong adsorption seems to limit their catalytic performance.
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Affiliation(s)
- Jenny Arnling Bååth
- Department
of Biotechnology and Biomedicine, Technical
University of Denmark, Søltofts Plads, Kgs. Lyngby DK-2800, Denmark
| | - Kenneth Jensen
- Novozymes
A/S, Biologiens Vej 2, Kgs. Lyngby DK-2800, Denmark
| | - Kim Borch
- Novozymes
A/S, Biologiens Vej 2, Kgs. Lyngby DK-2800, Denmark
| | - Peter Westh
- Department
of Biotechnology and Biomedicine, Technical
University of Denmark, Søltofts Plads, Kgs. Lyngby DK-2800, Denmark
- . Phone: +45 45 25 26 41
| | - Jeppe Kari
- Department
of Science and Environment, Roskilde University, Universitetsvej 1, Roskilde DK-4000, Denmark
- . Phone: +45 46 74 27 20
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28
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Wei R, von Haugwitz G, Pfaff L, Mican J, Badenhorst CP, Liu W, Weber G, Austin HP, Bednar D, Damborsky J, Bornscheuer UT. Mechanism-Based Design of Efficient PET Hydrolases. ACS Catal 2022; 12:3382-3396. [PMID: 35368328 PMCID: PMC8939324 DOI: 10.1021/acscatal.1c05856] [Citation(s) in RCA: 72] [Impact Index Per Article: 36.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2021] [Revised: 02/04/2022] [Indexed: 01/06/2023]
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.
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Affiliation(s)
- Ren Wei
- Institute
of Biochemistry, Department of Biotechnology & Enzyme Catalysis, University of Greifswald, Felix-Hausdorff-Str. 4, D-17487 Greifswald, Germany,
| | - Gerlis von Haugwitz
- Institute
of Biochemistry, Department of Biotechnology & Enzyme Catalysis, University of Greifswald, Felix-Hausdorff-Str. 4, D-17487 Greifswald, Germany
| | - Lara Pfaff
- Institute
of Biochemistry, Department of Biotechnology & Enzyme Catalysis, University of Greifswald, Felix-Hausdorff-Str. 4, D-17487 Greifswald, Germany
| | - Jan Mican
- Loschmidt
Laboratories, Department of Experimental Biology and RECETOX, Faculty
of Science, Masaryk University, 625 00 Brno, Czech Republic,International
Clinical Research Center, St. Anne’s University Hospital and
Faculty of Medicine, Masaryk University, 656 91 Brno, Czech Republic
| | - Christoffel P.
S. Badenhorst
- Institute
of Biochemistry, Department of Biotechnology & Enzyme Catalysis, University of Greifswald, Felix-Hausdorff-Str. 4, D-17487 Greifswald, Germany
| | - Weidong Liu
- Tianjin
Institute of Industrial Biotechnology, Chinese Academy of Sciences, 32 West 7th Avenue, Tianjin Airport
Economic Area, Tianjin, 300308, China
| | - Gert Weber
- Macromolecular
Crystallography, Helmholtz-Zentrum Berlin
für Materialien und Energie, Albert-Einstein-Straße 15, D-12489 Berlin, Germany
| | - Harry P. Austin
- Institute
of Biochemistry, Department of Biotechnology & Enzyme Catalysis, University of Greifswald, Felix-Hausdorff-Str. 4, D-17487 Greifswald, Germany
| | - David Bednar
- Loschmidt
Laboratories, Department of Experimental Biology and RECETOX, Faculty
of Science, Masaryk University, 625 00 Brno, Czech Republic,International
Clinical Research Center, St. Anne’s University Hospital and
Faculty of Medicine, Masaryk University, 656 91 Brno, Czech Republic
| | - Jiri Damborsky
- Loschmidt
Laboratories, Department of Experimental Biology and RECETOX, Faculty
of Science, Masaryk University, 625 00 Brno, Czech Republic,International
Clinical Research Center, St. Anne’s University Hospital and
Faculty of Medicine, Masaryk University, 656 91 Brno, Czech Republic
| | - Uwe T. Bornscheuer
- Institute
of Biochemistry, Department of Biotechnology & Enzyme Catalysis, University of Greifswald, Felix-Hausdorff-Str. 4, D-17487 Greifswald, Germany,
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29
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Chang AC, Patel A, Perry S, Soong YV, Ayafor C, Wong HW, Xie D, Sobkowicz MJ. Understanding consequences and tradeoffs of melt processing as a pretreatment for enzymatic depolymerization of poly(ethylene terephthalate). Macromol Rapid Commun 2022; 43:e2100929. [PMID: 35298859 DOI: 10.1002/marc.202100929] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2021] [Revised: 03/06/2022] [Indexed: 11/05/2022]
Abstract
dummy This article is protected by copyright. All rights reserved.
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Affiliation(s)
- Allen C Chang
- Plastics Engineering, University of Massachusetts Lowell, Lowell, MA, 01851, USA
| | - Akanksha Patel
- Plastics Engineering, University of Massachusetts Lowell, Lowell, MA, 01851, USA
| | - Sarah Perry
- Plastics Engineering, University of Massachusetts Lowell, Lowell, MA, 01851, USA
| | - Yahue V Soong
- Biomedical and Biotechnology, University of Massachusetts Lowell, Lowell, MA, 01851, USA
| | - Christian Ayafor
- Energy Engineering, University of Massachusetts Lowell, Lowell, MA, 01851, USA
| | - Hsi-Wu Wong
- Chemical Engineering, University of Massachusetts Lowell, Lowell, MA, 01851, USA
| | - Dongming Xie
- Chemical Engineering, University of Massachusetts Lowell, Lowell, MA, 01851, USA
| | - Margaret J Sobkowicz
- Plastics Engineering, University of Massachusetts Lowell, Lowell, MA, 01851, USA
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30
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Kim K, Song S, Sung J. Non‐steady‐state enzyme reaction dynamics. B KOREAN CHEM SOC 2022. [DOI: 10.1002/bkcs.12465] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Kyungwoo Kim
- Department of Chemistry and Institute of Innovative Functional Imaging Chung‐Ang University Seoul South Korea
| | - Sanggeun Song
- Department of Chemistry and Institute of Innovative Functional Imaging Chung‐Ang University Seoul South Korea
| | - Jaeyoung Sung
- Department of Chemistry and Institute of Innovative Functional Imaging Chung‐Ang University Seoul South Korea
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31
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Fanin N, Mooshammer M, Sauvadet M, Meng C, Alvarez G, Bernard L, Bertrand I, Blagodatskaya E, Bon L, Fontaine S, Niu S, Lashermes G, Maxwell TL, Weintraub M, Wingate L, Moorhead D, Nottingham A. Soil enzymes in response to climate warming: mechanisms and feedbacks. Funct Ecol 2022. [DOI: 10.1111/1365-2435.14027] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Affiliation(s)
- Nicolas Fanin
- INRAE Bordeaux Sciences Agro UMR 1391 ISPA 71 avenue Edouard Bourlaux, CS 20032 F33882 Villenave‐d’Ornon cedex France
| | - Maria Mooshammer
- Department of Environmental Science, Policy, and Management University of California Berkeley Berkeley CA USA
| | - Marie Sauvadet
- CIRAD UPR GECO F97285 Le Lamentin, Martinique France
- CIRAD, GECO Univ Montpellier Montpellier France
| | - Cheng Meng
- Key Laboratory of Ecosystem Network Observation and Modeling Institute of Geographic Sciences and Natural Resources Research Chinese Academy of Sciences Beijing 100101 China
| | - Gaël Alvarez
- INRAE Université Clermont Auvergne VetAgro Sup UMR Ecosystème Prairial 63000 Clermont Ferrand France
| | - Laëtitia Bernard
- INRAE IRD, CIRAD Institut Agro Univ Montpellier UMR Eco&Sols Montpellier France
| | - Isabelle Bertrand
- INRAE IRD, CIRAD Institut Agro Univ Montpellier UMR Eco&Sols Montpellier France
| | - Evgenia Blagodatskaya
- Department of Soil Ecology Helmholtz Centre for Environmental Research – UFZ Halle, Saale Germany
- Agro‐Technological Institute RUDN University Moscow Russia
| | - Lucie Bon
- INRAE Bordeaux Sciences Agro UMR 1391 ISPA 71 avenue Edouard Bourlaux, CS 20032 F33882 Villenave‐d’Ornon cedex France
| | - Sébastien Fontaine
- INRAE Université Clermont Auvergne VetAgro Sup UMR Ecosystème Prairial 63000 Clermont Ferrand France
| | - Shuli Niu
- Key Laboratory of Ecosystem Network Observation and Modeling Institute of Geographic Sciences and Natural Resources Research Chinese Academy of Sciences Beijing 100101 China
| | - Gwenaelle Lashermes
- INRAE Université de Reims Champagne‐Ardenne UMR A 614 FARE 51097 Reims France
| | - Tania L. Maxwell
- INRAE Bordeaux Sciences Agro UMR 1391 ISPA 71 avenue Edouard Bourlaux, CS 20032 F33882 Villenave‐d’Ornon cedex France
| | | | - Lisa Wingate
- INRAE Bordeaux Sciences Agro UMR 1391 ISPA 71 avenue Edouard Bourlaux, CS 20032 F33882 Villenave‐d’Ornon cedex France
| | - Daryl Moorhead
- Department of Environmental Sciences University of Toledo 2801 W. Bancroft St Toledo Ohio 43606‐3390 USA
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32
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Erickson E, Shakespeare TJ, Bratti F, Buss BL, Graham R, Hawkins MA, König G, Michener WE, Miscall J, Ramirez KJ, Rorrer NA, Zahn M, Pickford AR, McGeehan JE, Beckham GT. Comparative Performance of PETase as a Function of Reaction Conditions, Substrate Properties, and Product Accumulation. CHEMSUSCHEM 2022; 15:e202101932. [PMID: 34587366 DOI: 10.1002/cssc.202101932] [Citation(s) in RCA: 27] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/09/2021] [Revised: 09/28/2021] [Indexed: 05/21/2023]
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, the Ideonella sakaiensis PETase wild-type enzyme was compared to a previously reported improved variant (W159H/S238F). The thermostability of each enzyme was compared and a 1.45 Å resolution structure of the mutant was described, 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 showed that reaction temperature had the strongest influence on performance between the two enzymes. It was also shown that both enzymes achieved higher levels of PET conversion for substrates with moderate crystallinity relative to amorphous substrates. Finally, the impact of product accumulation on reaction progress was assessed for the hydrolysis of both PET and bis(2-hydroxyethyl) terephthalate (BHET). Each enzyme displayed different inhibition profiles to mono(2-hydroxyethyl) terephthalate (MHET) and TPA, while both were 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.
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Affiliation(s)
- Erika Erickson
- Renewable Resources and Enabling Sciences Center, National Renewable Energy Laboratory, Golden, CO 80401, United States
- BOTTLE Consortium, Golden, CO 80401, United States
| | - Thomas J Shakespeare
- BOTTLE Consortium, Golden, CO 80401, United States
- Centre for Enzyme Innovation, School of Biological Sciences, Institute of Biological and Biomedical Sciences, University of Portsmouth, Portsmouth, PO1 2DY, United Kingdom
| | - Felicia Bratti
- Renewable Resources and Enabling Sciences Center, National Renewable Energy Laboratory, Golden, CO 80401, United States
- BOTTLE Consortium, Golden, CO 80401, United States
| | - Bonnie L Buss
- Renewable Resources and Enabling Sciences Center, National Renewable Energy Laboratory, Golden, CO 80401, United States
- BOTTLE Consortium, Golden, CO 80401, United States
| | - Rosie Graham
- BOTTLE Consortium, Golden, CO 80401, United States
- Centre for Enzyme Innovation, School of Biological Sciences, Institute of Biological and Biomedical Sciences, University of Portsmouth, Portsmouth, PO1 2DY, United Kingdom
| | - McKenzie A Hawkins
- Renewable Resources and Enabling Sciences Center, National Renewable Energy Laboratory, Golden, CO 80401, United States
- BOTTLE Consortium, Golden, CO 80401, United States
| | - Gerhard König
- Centre for Enzyme Innovation, School of Biological Sciences, Institute of Biological and Biomedical Sciences, University of Portsmouth, Portsmouth, PO1 2DY, United Kingdom
| | - William E Michener
- Renewable Resources and Enabling Sciences Center, National Renewable Energy Laboratory, Golden, CO 80401, United States
- BOTTLE Consortium, Golden, CO 80401, United States
| | - Joel Miscall
- Renewable Resources and Enabling Sciences Center, National Renewable Energy Laboratory, Golden, CO 80401, United States
- BOTTLE Consortium, Golden, CO 80401, United States
| | - Kelsey J Ramirez
- Renewable Resources and Enabling Sciences Center, National Renewable Energy Laboratory, Golden, CO 80401, United States
- BOTTLE Consortium, Golden, CO 80401, United States
| | - Nicholas A Rorrer
- Renewable Resources and Enabling Sciences Center, National Renewable Energy Laboratory, Golden, CO 80401, United States
- BOTTLE Consortium, Golden, CO 80401, United States
| | - Michael Zahn
- Centre for Enzyme Innovation, School of Biological Sciences, Institute of Biological and Biomedical Sciences, University of Portsmouth, Portsmouth, PO1 2DY, United Kingdom
| | - Andrew R Pickford
- BOTTLE Consortium, Golden, CO 80401, United States
- Centre for Enzyme Innovation, School of Biological Sciences, Institute of Biological and Biomedical Sciences, University of Portsmouth, Portsmouth, PO1 2DY, United Kingdom
| | - John E McGeehan
- BOTTLE Consortium, Golden, CO 80401, United States
- Centre for Enzyme Innovation, School of Biological Sciences, Institute of Biological and Biomedical Sciences, University of Portsmouth, Portsmouth, PO1 2DY, United Kingdom
| | - Gregg T Beckham
- Renewable Resources and Enabling Sciences Center, National Renewable Energy Laboratory, Golden, CO 80401, United States
- BOTTLE Consortium, Golden, CO 80401, United States
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33
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Qu X, Zou J, Shen Y, Zhao B, Liang J, Wang Z, Zhang Y, Niu L. High-efficiency peroxidase mimics for fluorescence detection of H 2O 2 and l-cysteine. Analyst 2022; 147:1808-1814. [DOI: 10.1039/d1an02310a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A novel fluorescent sensor based on a Au–Ag bimetallic peroxidase-like enzyme was constructed for the sensitive detection of l-cysteine and H2O2.
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Affiliation(s)
- Xiaodan Qu
- State Key Laboratory of Electroanalytical Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun, Jilin, 130022, P.R. China
- University of Science and Technology of China, Hefei, Anhui, 230026, P.R. China
- Center for Advanced Analytical Science, c/o School of Chemistry and Chemical Engineering, Guangzhou Key Laboratory of Sensing Materials & Devices, Guangzhou University, Guangzhou, Guangdong, 510006, P. R. China
| | - Jinhui Zou
- Center for Advanced Analytical Science, c/o School of Chemistry and Chemical Engineering, Guangzhou Key Laboratory of Sensing Materials & Devices, Guangzhou University, Guangzhou, Guangdong, 510006, P. R. China
| | - Yujie Shen
- Center for Advanced Analytical Science, c/o School of Chemistry and Chemical Engineering, Guangzhou Key Laboratory of Sensing Materials & Devices, Guangzhou University, Guangzhou, Guangdong, 510006, P. R. China
| | - Bolin Zhao
- Center for Advanced Analytical Science, c/o School of Chemistry and Chemical Engineering, Guangzhou Key Laboratory of Sensing Materials & Devices, Guangzhou University, Guangzhou, Guangdong, 510006, P. R. China
- School of Civil Engineering, Guangzhou University, Guangzhou, Guangdong, 510006, P. R. China
| | - Jiahui Liang
- Center for Advanced Analytical Science, c/o School of Chemistry and Chemical Engineering, Guangzhou Key Laboratory of Sensing Materials & Devices, Guangzhou University, Guangzhou, Guangdong, 510006, P. R. China
| | - Zhenxin Wang
- State Key Laboratory of Electroanalytical Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun, Jilin, 130022, P.R. China
- University of Science and Technology of China, Hefei, Anhui, 230026, P.R. China
| | - Yuwei Zhang
- Center for Advanced Analytical Science, c/o School of Chemistry and Chemical Engineering, Guangzhou Key Laboratory of Sensing Materials & Devices, Guangzhou University, Guangzhou, Guangdong, 510006, P. R. China
| | - Li Niu
- Center for Advanced Analytical Science, c/o School of Chemistry and Chemical Engineering, Guangzhou Key Laboratory of Sensing Materials & Devices, Guangzhou University, Guangzhou, Guangdong, 510006, P. R. China
- School of Civil Engineering, Guangzhou University, Guangzhou, Guangdong, 510006, P. R. China
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Monclaro AV, Gorgulho Silva CDO, Gomes HAR, Moreira LRDS, Filho EXF. The enzyme interactome concept in filamentous fungi linked to biomass valorization. BIORESOURCE TECHNOLOGY 2022; 344:126200. [PMID: 34710591 DOI: 10.1016/j.biortech.2021.126200] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/28/2021] [Revised: 10/19/2021] [Accepted: 10/20/2021] [Indexed: 05/15/2023]
Abstract
Biomass represents an abundant and inexpensive source of sugars and aromatic compounds that can be used as raw materials for conversion into value-added bioproducts. Filamentous fungi are sources of plant cell wall degrading enzymes in nature. Understanding the interactions between enzymes is crucial for optimizing biomass degradation processes. Herein, the concept of the interactome is presented as a holistic approach that depicts the interactions among enzymes, substrates, metabolites, and inhibitors. The interactome encompasses several stages of biomass degradation, starting with the sensing of the substrate and the subsequent synthesis of hydrolytic and oxidative enzymes (fungus-substrate interaction). Enzyme-enzyme interactions are exemplified in the complex processes of lignocellulosic biomass degradation. The enzyme-substrate-metabolite-inhibitor interaction also provides a better understanding of biomass conversion, allowing bioproduct production from recalcitrant agro-industrial residues, thus bringing greater value to residual biomass. Finally, technological applications are presented for optimizing the interactome at various levels.
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Affiliation(s)
- Antonielle Vieira Monclaro
- Center for Microbial Ecology and Technology (CMET), Department of Biotechnology, Faculty of Bioscience Engineering, Ghent University, Coupure Links 653, 9000 Ghent, Belgium; Center for Advanced Process Technology and Urban Resource Efficiency (CAPTURE), Frieda Saeysstraat, 9052 Ghent, Belgium
| | - Caio de Oliveira Gorgulho Silva
- Faculty of Chemistry, Biotechnology and Food Science, Norwegian University of Life Sciences (NMBU), P.O. Box 5003, 1432 Ås, Norway; Protein Chemistry and Enzyme Technology Section, DTU Bioengineering, Department of Biotechnology and Biomedicine, Technical University of Denmark, 2800 Kgs Lyngby, Denmark
| | - Helder Andrey Rocha Gomes
- Health Science School, University Center of the Federal District (UDF), DF, Brasília 70390045, Brazil
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Rennison A, Winther JR, Varrone C. Rational Protein Engineering to Increase the Activity and Stability of IsPETase Using the PROSS Algorithm. Polymers (Basel) 2021; 13:polym13223884. [PMID: 34833182 PMCID: PMC8621346 DOI: 10.3390/polym13223884] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2021] [Revised: 11/01/2021] [Accepted: 11/04/2021] [Indexed: 02/07/2023] Open
Abstract
Polyethylene terephthalate (PET) is the most widely used polyester plastic, with applications in the textile and packaging industry. Currently, re-moulding is the main path for PET recycling, but this eventually leads to an unsustainable loss of quality; thus, other means of recycling are required. Enzymatic hydrolysis offers the possibility of monomer formation under mild conditions and opens up alternative and infinite recycling paths. Here, IsPETase, derived from the bacterium Ideonella sakaiensis, is considered to be the most active enzyme for PET degradation under mild conditions, and although several studies have demonstrated improvements to both the stability and activity of this enzyme, stability at even moderate temperatures is still an issue. In the present study, we have used sequence and structure-based bioinformatic tools to identify mutations to increase the thermal stability of the enzyme so as to increase PET degradation activity during extended hydrolysis reactions. We found that amino acid substitution S136E showed significant increases to activity and stability. S136E is a previously unreported variant that led to a 3.3-fold increase in activity relative to wild type.
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Affiliation(s)
- Andrew Rennison
- Section for Biomolecular Sciences, Linderstrøm-Lang Centre for Protein Science, Department of Biology, University of Copenhagen, Ole Maaloes Vej 5, 2200 Copenhagen, Denmark;
| | - Jakob R. Winther
- Section for Biomolecular Sciences, Linderstrøm-Lang Centre for Protein Science, Department of Biology, University of Copenhagen, Ole Maaloes Vej 5, 2200 Copenhagen, Denmark;
- Correspondence: (J.R.W.); (C.V.)
| | - Cristiano Varrone
- Section for Sustainable Biotechnology, Department of Chemistry and BioScience, Aalborg University, A.C. Meyers Vænge 15, C2, 2450 Copenhagen, Denmark
- Correspondence: (J.R.W.); (C.V.)
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Pirillo V, Pollegioni L, Molla G. Analytical methods for the investigation of enzyme-catalyzed degradation of polyethylene terephthalate. FEBS J 2021; 288:4730-4745. [PMID: 33792200 PMCID: PMC8453989 DOI: 10.1111/febs.15850] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2020] [Revised: 03/03/2021] [Accepted: 03/29/2021] [Indexed: 01/11/2023]
Abstract
The polyester PET (poly(ethylene terephthalate)) plastic is chemically inert and remarkably persistent, posing relevant and global pollution concerns due to its accumulation in ecosystems across the globe. In past years, research focused on identifying bacteria active on PET and on the specific enzymes responsible for its degradation. Here, the enzymatic degradation of PET can be considered as an 'erosion process' that takes place on the surface of an insoluble material and results in an unusual, substrate-limited kinetic condition. In this review, we report on the most suitable models to evaluate the kinetics of PET-hydrolyzing enzymes, which takes into consideration the amount of enzyme adsorbed on the substrate, the enzyme-accessible ester bonds, and the product inhibition effects. Careful kinetic analysis is especially relevant to compare enzymes from different sources and evolved variants generated by protein engineering studies as well. Furthermore, the analytical methods most suitable to screen natural bacteria and recombinant variant libraries generated by protein engineering have been also reported. These methods rely on different detection systems and are performed both on model compounds and on different PET samples (e.g., nanoparticles, microparticles, and waste products). All this meaningful information represents an optimal starting point and boosts the process of identifying systems able to biologically recycle PET waste products.
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Affiliation(s)
- Valentina Pirillo
- The Protein Factory 2.0’Dipartimento di Biotecnologie e Scienze della VitaUniversità degli Studi dell'InsubriaVareseItaly
| | - Loredano Pollegioni
- The Protein Factory 2.0’Dipartimento di Biotecnologie e Scienze della VitaUniversità degli Studi dell'InsubriaVareseItaly
| | - Gianluca Molla
- The Protein Factory 2.0’Dipartimento di Biotecnologie e Scienze della VitaUniversità degli Studi dell'InsubriaVareseItaly
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Ellis LD, Rorrer NA, Sullivan KP, Otto M, McGeehan JE, Román-Leshkov Y, Wierckx N, Beckham GT. Chemical and biological catalysis for plastics recycling and upcycling. Nat Catal 2021. [DOI: 10.1038/s41929-021-00648-4] [Citation(s) in RCA: 117] [Impact Index Per Article: 39.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
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38
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Kari J, Molina GA, Schaller KS, Schiano-di-Cola C, Christensen SJ, Badino SF, Sørensen TH, Røjel NS, Keller MB, Sørensen NR, Kolaczkowski B, Olsen JP, Krogh KBRM, Jensen K, Cavaleiro AM, Peters GHJ, Spodsberg N, Borch K, Westh P. Physical constraints and functional plasticity of cellulases. Nat Commun 2021; 12:3847. [PMID: 34158485 PMCID: PMC8219668 DOI: 10.1038/s41467-021-24075-y] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2020] [Accepted: 05/17/2021] [Indexed: 11/16/2022] Open
Abstract
Enzyme reactions, both in Nature and technical applications, commonly occur at the interface of immiscible phases. Nevertheless, stringent descriptions of interfacial enzyme catalysis remain sparse, and this is partly due to a shortage of coherent experimental data to guide and assess such work. In this work, we produced and kinetically characterized 83 cellulases, which revealed a conspicuous linear free energy relationship (LFER) between the substrate binding strength and the activation barrier. The scaling occurred despite the investigated enzymes being structurally and mechanistically diverse. We suggest that the scaling reflects basic physical restrictions of the hydrolytic process and that evolutionary selection has condensed cellulase phenotypes near the line. One consequence of the LFER is that the activity of a cellulase can be estimated from its substrate binding strength, irrespectively of structural and mechanistic details, and this appears promising for in silico selection and design within this industrially important group of enzymes.
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Affiliation(s)
- Jeppe Kari
- Department of Biotechnology and Biomedicine, Technical University of Denmark, Kongens Lyngby, Denmark
| | - Gustavo A Molina
- Department of Biotechnology and Biomedicine, Technical University of Denmark, Kongens Lyngby, Denmark
| | - Kay S Schaller
- Department of Biotechnology and Biomedicine, Technical University of Denmark, Kongens Lyngby, Denmark
| | - Corinna Schiano-di-Cola
- Department of Biotechnology and Biomedicine, Technical University of Denmark, Kongens Lyngby, Denmark
| | - Stefan J Christensen
- Department of Biotechnology and Biomedicine, Technical University of Denmark, Kongens Lyngby, Denmark
| | - Silke F Badino
- Department of Biotechnology and Biomedicine, Technical University of Denmark, Kongens Lyngby, Denmark
| | | | - Nanna S Røjel
- Department of Science and Environment, Roskilde University, Universitetsvej 1, Roskilde, Denmark
| | - Malene B Keller
- Department of Geosciences and Natural Resource Management, University of Copenhagen, Frederiksberg C, Denmark
| | - Nanna Rolsted Sørensen
- Department of Science and Environment, Roskilde University, Universitetsvej 1, Roskilde, Denmark
| | - Bartlomiej Kolaczkowski
- Department of Science and Environment, Roskilde University, Universitetsvej 1, Roskilde, Denmark
| | | | | | | | | | - Günther H J Peters
- Department of Chemistry, Technical University of Denmark, Kongens Lyngby, Denmark
| | | | | | - Peter Westh
- Department of Biotechnology and Biomedicine, Technical University of Denmark, Kongens Lyngby, Denmark.
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Vogel K, Wei R, Pfaff L, Breite D, Al-Fathi H, Ortmann C, Estrela-Lopis I, Venus T, Schulze A, Harms H, Bornscheuer UT, Maskow T. Enzymatic degradation of polyethylene terephthalate nanoplastics analyzed in real time by isothermal titration calorimetry. THE SCIENCE OF THE TOTAL ENVIRONMENT 2021; 773:145111. [PMID: 33940717 DOI: 10.1016/j.scitotenv.2021.145111] [Citation(s) in RCA: 29] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/15/2020] [Revised: 01/06/2021] [Accepted: 01/06/2021] [Indexed: 06/12/2023]
Abstract
Plastics are globally used for a variety of benefits. As a consequence of poor recycling or reuse, improperly disposed plastic waste accumulates in terrestrial and aquatic ecosystems to a considerable extent. Large plastic waste items become fragmented to small particles through mechanical and (photo)chemical processes. Particles with sizes ranging from millimeter (microplastics, <5 mm) to nanometer (nanoplastics, NP, <100 nm) are apparently persistent and have adverse effects on ecosystems and human health. Current research therefore focuses on whether and to what extent microorganisms or enzymes can degrade these NP. In this study, we addressed the question of what information isothermal titration calorimetry, which tracks the heat of reaction of the chain scission of a polyester, can provide about the kinetics and completeness of the degradation process. The majority of the heat represents the cleavage energy of the ester bonds in polymer backbones providing real-time kinetic information. Calorimetry operates even in complex matrices. Using the example of the cutinase-catalyzed degradation of polyethylene terephthalate (PET) nanoparticles, we found that calorimetry (isothermal titration calorimetry-ITC) in combination with thermokinetic models is excellently suited for an in-depth analysis of the degradation processes of NP. For instance, we can separately quantify i) the enthalpy of surface adsorption ∆AdsH = 129 ± 2 kJ mol-1, ii) the enthalpy of the cleavage of the ester bonds ∆EBH = -58 ± 1.9 kJ mol-1 and the apparent equilibrium constant of the enzyme substrate complex K = 0.046 ± 0.015 g L-1. It could be determined that the heat production of PET NP degradation depends to 95% on the reaction heat and only to 5% on the adsorption heat. The fact that the percentage of cleaved ester bonds (η = 12.9 ± 2.4%) is quantifiable with the new method is of particular practical importance. The new method promises a quantification of enzymatic and microbial adsorption to NP and their degradation in mimicked real-world aquatic conditions.
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Affiliation(s)
- Kristina Vogel
- Department of Environmental Microbiology, Helmholtz-Centre for Environmental Research - UFZ, Permoserstraße 15, D-04318 Leipzig, Germany; Institute for Drug Discovery, Leipzig University Medical School, Leipzig University, Bruederstr, 34, D-04103 Leipzig, Germany
| | - Ren Wei
- Department of Biotechnology and Enzyme Catalysis, Institute for Biochemistry, University of Greifswald, Felix-Hausdorff-Str. 4, D-17487 Greifswald, Germany.
| | - Lara Pfaff
- Department of Biotechnology and Enzyme Catalysis, Institute for Biochemistry, University of Greifswald, Felix-Hausdorff-Str. 4, D-17487 Greifswald, Germany
| | - Daniel Breite
- Leibniz Institute of Surface Engineering (IOM), Permoserstraße 15, D-04318 Leipzig, Germany
| | - Hassan Al-Fathi
- Department of Environmental Microbiology, Helmholtz-Centre for Environmental Research - UFZ, Permoserstraße 15, D-04318 Leipzig, Germany
| | | | - Irina Estrela-Lopis
- Institute for Medical Physics and Biophysics, Medical Faculty, Leipzig University, Härtelstr, 16-18, D-04107 Leipzig, Germany
| | - Tom Venus
- Institute for Medical Physics and Biophysics, Medical Faculty, Leipzig University, Härtelstr, 16-18, D-04107 Leipzig, Germany
| | - Agnes Schulze
- Leibniz Institute of Surface Engineering (IOM), Permoserstraße 15, D-04318 Leipzig, Germany
| | - Hauke Harms
- Department of Environmental Microbiology, Helmholtz-Centre for Environmental Research - UFZ, Permoserstraße 15, D-04318 Leipzig, Germany
| | - Uwe T Bornscheuer
- Department of Biotechnology and Enzyme Catalysis, Institute for Biochemistry, University of Greifswald, Felix-Hausdorff-Str. 4, D-17487 Greifswald, Germany
| | - Thomas Maskow
- Department of Environmental Microbiology, Helmholtz-Centre for Environmental Research - UFZ, Permoserstraße 15, D-04318 Leipzig, Germany.
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40
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Anuganti M, Fu H, Ekatan S, Kumar CV, Lin Y. Kinetic Study on Enzymatic Hydrolysis of Cellulose in an Open, Inhibition-Free System. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2021; 37:5180-5192. [PMID: 33872034 DOI: 10.1021/acs.langmuir.1c00115] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Due to the complexity of cellulases and the requirement of enzyme adsorption on cellulose prior to reactions, it is difficult to evaluate their reaction with a general mechanistic scheme. Nevertheless, it is of great interest to come up with an approximate analytic description of a valid model for the purpose of developing an intuitive understanding of these complex enzyme systems. Herein, we used the surface plasmonic resonance method to monitor the action of a cellobiohydrolase by itself, as well as its mixture with a synergetic endoglucanase, on the surface of a regenerated model cellulose film, under continuous flow conditions. We found a phenomenological approach by taking advantage of the long steady state of cellulose hydrolysis in the open, inhibition-free system. This provided a direct and reliable way to analyze the adsorption and reaction processes with a minimum number of fitting parameters. We investigated a generalized Langmuir-Michaelis-Menten model to describe a full set of kinetic results across a range of enzyme concentrations, compositions, and temperatures. The overall form of the equations describing the pseudo-steady-state kinetics of the flow-system shares some interesting similarities with the Michaelis-Menten equation. The use of familiar Michaelis-Menten parameters in the analysis provides a unifying framework to study cellulase kinetics. The strategy may provide a shortcut for approaching a quantitative while intuitive understanding of enzymatic degradation of cellulose from top to bottom. The open system approach and the kinetic analysis should be applicable to a variety of cellulases and reaction systems to accelerate the progress in the field.
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Affiliation(s)
- Murali Anuganti
- Department of Chemistry, University of Connecticut, Storrs, Connecticut 06269, United States
| | - Hailin Fu
- Department of Chemistry, University of Connecticut, Storrs, Connecticut 06269, United States
| | - Stephen Ekatan
- Polymer Program, Institute of Material Sciences, University of Connecticut, Storrs, Connecticut 06269, United States
| | - Challa V Kumar
- Department of Chemistry, University of Connecticut, Storrs, Connecticut 06269, United States
| | - Yao Lin
- Department of Chemistry, University of Connecticut, Storrs, Connecticut 06269, United States
- Polymer Program, Institute of Material Sciences, University of Connecticut, Storrs, Connecticut 06269, United States
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Piovarci I, Melikishvili S, Tatarko M, Hianik T, Thompson M. Detection of Sub-Nanomolar Concentration of Trypsin by Thickness-Shear Mode Acoustic Biosensor and Spectrophotometry. BIOSENSORS 2021; 11:117. [PMID: 33920444 PMCID: PMC8070231 DOI: 10.3390/bios11040117] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/11/2021] [Revised: 03/26/2021] [Accepted: 04/06/2021] [Indexed: 05/03/2023]
Abstract
The determination of protease activity is very important for disease diagnosis, drug development, and quality and safety assurance for dairy products. Therefore, the development of low-cost and sensitive methods for assessing protease activity is crucial. We report two approaches for monitoring protease activity: in a volume and at surface, via colorimetric and acoustic wave-based biosensors operated in the thickness-shear mode (TSM), respectively. The TSM sensor was based on a β-casein substrate immobilized on a piezoelectric quartz crystal transducer. After an enzymatic reaction with trypsin, it cleaved the surface-bound β-casein, which increased the resonant frequency of the crystal. The limit of detection (LOD) was 0.48 ± 0.08 nM. A label-free colorimetric assay for trypsin detection has also been performed using β-casein and 6-mercaptohexanol (MCH) functionalized gold nanoparticles (AuNPs/MCH-β-casein). Due to the trypsin cleavage of β-casein, the gold nanoparticles lost shelter, and MCH increased the attractive force between the modified AuNPs. Consequently, AuNPs aggregated, and the red shift of the absorption spectra was observed. Spectrophotometric assay enabled an LOD of 0.42 ± 0.03 nM. The Michaelis-Menten constant, KM, for reverse enzyme reaction has also been estimated by both methods. This value for the colorimetric assay (0.56 ± 0.10 nM) is lower in comparison with those for the TSM sensor (0.92 ± 0.44 nM). This is likely due to the better access of the trypsin to the β-casein substrate at the surface of AuNPs in comparison with those at the TSM transducer.
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Affiliation(s)
- Ivan Piovarci
- Department of Nuclear Physics and Biophysics, Faculty of Mathematics, Physics and Informatics, Comenius University, Mlynska dolina F1, 84248 Bratislava, Slovakia; (I.P.); (S.M.); (M.T.)
| | - Sopio Melikishvili
- Department of Nuclear Physics and Biophysics, Faculty of Mathematics, Physics and Informatics, Comenius University, Mlynska dolina F1, 84248 Bratislava, Slovakia; (I.P.); (S.M.); (M.T.)
| | - Marek Tatarko
- Department of Nuclear Physics and Biophysics, Faculty of Mathematics, Physics and Informatics, Comenius University, Mlynska dolina F1, 84248 Bratislava, Slovakia; (I.P.); (S.M.); (M.T.)
| | - Tibor Hianik
- Department of Nuclear Physics and Biophysics, Faculty of Mathematics, Physics and Informatics, Comenius University, Mlynska dolina F1, 84248 Bratislava, Slovakia; (I.P.); (S.M.); (M.T.)
| | - Michael Thompson
- Lash Miller Laboratories, Department of Chemistry, University of Toronto, Toronto, ON M5S 3H6, Canada
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Møller MS, El Bouaballati S, Henrissat B, Svensson B. Functional diversity of three tandem C-terminal carbohydrate-binding modules of a β-mannanase. J Biol Chem 2021; 296:100638. [PMID: 33838183 PMCID: PMC8121702 DOI: 10.1016/j.jbc.2021.100638] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2020] [Revised: 03/29/2021] [Accepted: 04/05/2021] [Indexed: 11/16/2022] Open
Abstract
Carbohydrate active enzymes, such as those involved in plant cell wall and storage polysaccharide biosynthesis and deconstruction, often contain repeating noncatalytic carbohydrate-binding modules (CBMs) to compensate for low-affinity binding typical of protein–carbohydrate interactions. The bacterium Saccharophagus degradans produces an endo-β-mannanase of glycoside hydrolase family 5 subfamily 8 with three phylogenetically distinct family 10 CBMs located C-terminally from the catalytic domain (SdGH5_8-CBM10x3). However, the functional roles and cooperativity of these CBM domains in polysaccharide binding are not clear. To learn more, we studied the full-length enzyme, three stepwise CBM family 10 (CBM10) truncations, and GFP fusions of the individual CBM10s and all three domains together by pull-down assays, affinity gel electrophoresis, and activity assays. Only the C-terminal CBM10-3 was found to bind strongly to microcrystalline cellulose (dissociation constant, Kd = 1.48 μM). CBM10-3 and CBM10-2 bound galactomannan with similar affinity (Kd = 0.2–0.4 mg/ml), but CBM10-1 had 20-fold lower affinity for this substrate. CBM10 truncations barely affected specific activity on carob galactomannan and konjac glucomannan. Full-length SdGH5_8-CBM10x3 was twofold more active on the highly galactose-decorated viscous guar gum galactomannan and crystalline ivory nut mannan at high enzyme concentrations, but the specific activity was fourfold to ninefold reduced at low enzyme and substrate concentrations compared with the enzyme lacking CBM10-2 and CBM10-3. Comparison of activity and binding data for the different enzyme forms indicates unproductive and productive polysaccharide binding to occur. We conclude that the C-terminal-most CBM10-3 secures firm binding, with contribution from CBM10-2, which with CBM10-1 also provides spatial flexibility.
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Affiliation(s)
- Marie Sofie Møller
- Department of Biotechnology and Biomedicine, Technical University of Denmark, Lyngby, Denmark.
| | - Souad El Bouaballati
- Department of Biotechnology and Biomedicine, Technical University of Denmark, Lyngby, Denmark
| | - Bernard Henrissat
- Architecture et Fonction des Macromolécules Biologiques, CNRS, Aix-Marseille Université, Marseille, France; Department of Biological Sciences, King Abdulaziz University, Jeddah, Saudi Arabia
| | - Birte Svensson
- Department of Biotechnology and Biomedicine, Technical University of Denmark, Lyngby, Denmark
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A comparative biochemical investigation of the impeding effect of C1-oxidizing LPMOs on cellobiohydrolases. J Biol Chem 2021; 296:100504. [PMID: 33675751 PMCID: PMC8047454 DOI: 10.1016/j.jbc.2021.100504] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2021] [Revised: 02/17/2021] [Accepted: 03/02/2021] [Indexed: 11/20/2022] Open
Abstract
Lytic polysaccharide monooxygenases (LPMOs) are known to act synergistically with glycoside hydrolases in industrial cellulolytic cocktails. However, a few studies have reported severe impeding effects of C1-oxidizing LPMOs on the activity of reducing-end cellobiohydrolases. The mechanism for this effect remains unknown, but it may have important implications as reducing-end cellobiohydrolases make up a significant part of such cocktails. To elucidate whether the impeding effect is general for different reducing-end cellobiohydrolases and study the underlying mechanism, we conducted a comparative biochemical investigation of the cooperation between a C1-oxidizing LPMO from Thielavia terrestris and three reducing-end cellobiohydrolases; Trichoderma reesei (TrCel7A), T. terrestris (TtCel7A), and Myceliophthora heterothallica (MhCel7A). The enzymes were heterologously expressed in the same organism and thoroughly characterized biochemically. The data showed distinct differences in synergistic effects between the LPMO and the cellobiohydrolases; TrCel7A was severely impeded, TtCel7A was moderately impeded, while MhCel7A was slightly boosted by the LPMO. We investigated effects of C1-oxidations on cellulose chains on the activity of the cellobiohydrolases and found reduced activity against oxidized cellulose in steady-state and pre-steady-state experiments. The oxidations led to reduced maximal velocity of the cellobiohydrolases and reduced rates of substrate complexation. The extent of these effects differed for the cellobiohydrolases and scaled with the extent of the impeding effect observed in the synergy experiments. Based on these results, we suggest that C1-oxidized chain ends are poor attack sites for reducing-end cellobiohydrolases. The severity of the impeding effects varied considerably among the cellobiohydrolases, which may be relevant to consider for optimization of industrial cocktails.
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Bååth JA, Borch K, Jensen K, Brask J, Westh P. Comparative Biochemistry of Four Polyester (PET) Hydrolases*. Chembiochem 2021; 22:1627-1637. [PMID: 33351214 DOI: 10.1002/cbic.202000793] [Citation(s) in RCA: 38] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2020] [Revised: 12/22/2020] [Indexed: 11/08/2022]
Abstract
The potential of bioprocessing in a circular plastic economy has strongly stimulated research into the enzymatic degradation of different synthetic polymers. Particular interest has been devoted to the commonly used polyester, poly(ethylene terephthalate) (PET), and a number of PET hydrolases have been described. However, a kinetic framework for comparisons of PET hydrolases (or other plastic-degrading enzymes) acting on the insoluble substrate has not been established. Herein, we propose such a framework, which we have tested against kinetic measurements for four PET hydrolases. The analysis provided values of kcat and KM , as well as an apparent specificity constant in the conventional units of M-1 s-1 . These parameters, together with experimental values for the number of enzyme attack sites on the PET surface, enabled comparative analyses. A variant of the PET hydrolase from Ideonella sakaiensis was the most efficient enzyme at ambient conditions; it relied on a high kcat rather than a low KM . Moreover, both soluble and insoluble PET fragments were consistently hydrolyzed much faster than intact PET. This suggests that interactions between polymer strands slow down PET degradation, whereas the chemical steps of catalysis and the low accessibility associated with solid substrate were less important for the overall rate. Finally, the investigated enzymes showed a remarkable substrate affinity, and reached half the saturation rate on PET when the concentration of attack sites in the suspension was only about 50 nM. We propose that this is linked to nonspecific adsorption, which promotes the nearness of enzyme and attack sites.
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Affiliation(s)
- Jenny Arnling Bååth
- Department of Biotechnology and Biomedicine, Technical University of Denmark, Søltofts Plads, 2800 Kgs., Lyngby, Denmark
| | - Kim Borch
- Novozymes A/S, Biologiens Vej 2, 2800 Kgs., Lyngby, Denmark
| | - Kenneth Jensen
- Novozymes A/S, Biologiens Vej 2, 2800 Kgs., Lyngby, Denmark
| | - Jesper Brask
- Novozymes A/S, Biologiens Vej 2, 2800 Kgs., Lyngby, Denmark
| | - Peter Westh
- Department of Biotechnology and Biomedicine, Technical University of Denmark, Søltofts Plads, 2800 Kgs., Lyngby, Denmark
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45
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Srinivasan B. Explicit Treatment of Non-Michaelis-Menten and Atypical Kinetics in Early Drug Discovery*. ChemMedChem 2020; 16:899-918. [PMID: 33231926 DOI: 10.1002/cmdc.202000791] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2020] [Indexed: 12/27/2022]
Abstract
Biological systems are highly regulated. They are also highly resistant to sudden perturbations enabling them to maintain the dynamic equilibrium essential to sustain life. This robustness is conferred by regulatory mechanisms that influence the activity of enzymes/proteins within their cellular context to adapt to changing environmental conditions. However, the initial rules governing the study of enzyme kinetics were mostly tested and implemented for cytosolic enzyme systems that were easy to isolate and/or recombinantly express. Moreover, these enzymes lacked complex regulatory modalities. Now, with academic labs and pharmaceutical companies turning their attention to more-complex systems (for instance, multiprotein complexes, oligomeric assemblies, membrane proteins and post-translationally modified proteins), the initial axioms defined by Michaelis-Menten (MM) kinetics are rendered inadequate, and the development of a new kind of kinetic analysis to study these systems is required. This review strives to present an overview of enzyme kinetic mechanisms that are atypical and, oftentimes, do not conform to the classical MM kinetics. Further, it presents initial ideas on the design and analysis of experiments in early drug-discovery for such systems, to enable effective screening and characterisation of small-molecule inhibitors with desirable physiological outcomes.
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Affiliation(s)
- Bharath Srinivasan
- Mechanistic Biology and Profiling Discovery Sciences, R&D, AstraZeneca, 310, Milton Rd, Milton CB4 0WG, Cambridge, UK
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46
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A steady-state approach for inhibition of heterogeneous enzyme reactions. Biochem J 2020; 477:1971-1982. [PMID: 32391552 DOI: 10.1042/bcj20200083] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2020] [Revised: 05/07/2020] [Accepted: 05/11/2020] [Indexed: 02/02/2023]
Abstract
The kinetic theory of enzymes that modify insoluble substrates is still underdeveloped, despite the prevalence of this type of reaction both in vivo and industrial applications. Here, we present a steady-state kinetic approach to investigate inhibition occurring at the solid-liquid interface. We propose to conduct experiments under enzyme excess (E0 ≫ S0), i.e. the opposite limit compared with the conventional Michaelis-Menten framework. This inverse condition is practical for insoluble substrates and elucidates how the inhibitor reduces enzyme activity through binding to the substrate. We claim that this type of inhibition is common for interfacial enzyme reactions because substrate accessibility is low, and we show that it can be analyzed by experiments and rate equations that are analogous to the conventional approach, except that the roles of enzyme and substrate have been swapped. To illustrate the approach, we investigated the major cellulases from Trichoderma reesei (Cel6A and Cel7A) acting on insoluble cellulose. As model inhibitors, we used catalytically inactive variants of Cel6A and Cel7A. We made so-called inverse Michaelis-Menten curves at different concentrations of inhibitors and found that a new rate equation accounted well for the data. In most cases, we found a mixed type of surface-site inhibition mechanism, and this probably reflected that the inhibitor both competed with the enzyme for the productive binding-sites (competitive inhibition) and hampered the processive movement on the surface (uncompetitive inhibition). These results give new insights into the complex interplay of Cel7A and Cel6A on cellulose and the approach may be applicable to other heterogeneous enzyme reactions.
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47
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Kont R, Bissaro B, Eijsink VGH, Väljamäe P. Kinetic insights into the peroxygenase activity of cellulose-active lytic polysaccharide monooxygenases (LPMOs). Nat Commun 2020; 11:5786. [PMID: 33188177 PMCID: PMC7666214 DOI: 10.1038/s41467-020-19561-8] [Citation(s) in RCA: 51] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2020] [Accepted: 10/13/2020] [Indexed: 01/06/2023] Open
Abstract
Lytic polysaccharide monooxygenases (LPMOs) are widely distributed in Nature, where they catalyze the hydroxylation of glycosidic bonds in polysaccharides. Despite the importance of LPMOs in the global carbon cycle and in industrial biomass conversion, the catalytic properties of these monocopper enzymes remain enigmatic. Strikingly, there is a remarkable lack of kinetic data, likely due to a multitude of experimental challenges related to the insoluble nature of LPMO substrates, like cellulose and chitin, and to the occurrence of multiple side reactions. Here, we employed competition between well characterized reference enzymes and LPMOs for the H2O2 co-substrate to kinetically characterize LPMO-catalyzed cellulose oxidation. LPMOs of both bacterial and fungal origin showed high peroxygenase efficiencies, with kcat/KmH2O2 values in the order of 105-106 M-1 s-1. Besides providing crucial insight into the cellulolytic peroxygenase reaction, these results show that LPMOs belonging to multiple families and active on multiple substrates are true peroxygenases.
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Affiliation(s)
- Riin Kont
- Institute of Molecular and Cell Biology, University of Tartu, Tartu, Estonia
| | - Bastien Bissaro
- Faculty of Chemistry, Biotechnology and Food Science, NMBU-Norwegian University of Life Sciences, Ås, Norway.,INRAE, Aix Marseille University, UMR1163 Biodiversité et Biotechnologie Fongiques, 13009, Marseille, France
| | - Vincent G H Eijsink
- Faculty of Chemistry, Biotechnology and Food Science, NMBU-Norwegian University of Life Sciences, Ås, Norway
| | - Priit Väljamäe
- Institute of Molecular and Cell Biology, University of Tartu, Tartu, Estonia.
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48
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Abstract
Enzymology is concerned with the study of enzyme structure, function, regulation and kinetics. It is an interdisciplinary subject that can be treated as an exclusive sphere of exhaustive inquiry within mathematical, physico-chemical and biological sciences. Hence, teaching of enzymology, in general, and enzyme kinetics, in particular, should be undertaken in an interdisciplinary manner for a holistic appreciation of this subject. Further, analogous examples from everyday life should form an integral component of the teaching for an intuitive grasp of the subject matter. Furthermore, simulation-based appreciation of enzyme kinetics should be preferred over simplifying assumptions and approximations of traditional enzyme kinetics teaching. In this Words of Advice, I outline the domain depth of enzymology across the various disciplines and provide initial ideas on how appropriate analogies can provide firm insights into the subject. Further, I demonstrate how an intuitive feel for the subject can help not only in grasping abstract concepts but also extending it in experimental design and subsequent interpretation. Use of simulations in grasping complex concepts is also advocated given the advantages this medium offers over traditional approaches involving images and molecular models. Furthermore, I discuss the merits of incorporating the historical backdrop of major discoveries in enzymological teaching. We, at AstraZeneca, have experimented with this approach with the desired outcome of generating interest in the subject from people practising diverse disciplines.
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Affiliation(s)
- Bharath Srinivasan
- Mechanistic Biology and Profiling, Discovery Sciences, R&D, AstraZeneca, Cambridge, UK
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49
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Chen Y, Jiao L, Yan H, Xu W, Wu Y, Wang H, Gu W, Zhu C. Hierarchically Porous S/N Codoped Carbon Nanozymes with Enhanced Peroxidase-like Activity for Total Antioxidant Capacity Biosensing. Anal Chem 2020; 92:13518-13524. [PMID: 32869631 DOI: 10.1021/acs.analchem.0c02982] [Citation(s) in RCA: 61] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Design of highly active carbon nanozymes and further establishment of ultrasensitive biosensors remain a challenge. Herein, hierarchically porous carbon nanozymes with sulfur (S)/nitrogen (N) codoping (SNC) were developed. Compared with N-doped carbon (NC) nanozymes, SNC nanozymes have a smaller Michaelis-Menten constant and higher specific activities, demonstrating that the S-doping in SNC nanozymes could not only enhance their affinity toward substrates but also improve their catalytic performance. These results may be caused by the synergistic effect of heteroatoms (S and N). Because of the good enzyme-like activity, the proposed SNC nanozymes were exploited to the colorimetric detection of the total antioxidant capacity (TAC) using ascorbic acid as a typical model with a limit of detection of 0.08 mM. Because of its high sensitivity and selectivity and encouraging performance, the detection method presented practical feasibility for the TAC assay in commercial beverages. This work paves a way to design the highly active carbon nanozymes and expand their applications in the construction of high-performance biosensors.
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Affiliation(s)
- Yifeng Chen
- Key Laboratory of Pesticide and Chemical Biology of Ministry of Education, International Joint Research Center for Intelligent Biosensing Technology and Health, College of Chemistry, Central China Normal University, Wuhan 430079, P.R. China
| | - Lei Jiao
- Key Laboratory of Pesticide and Chemical Biology of Ministry of Education, International Joint Research Center for Intelligent Biosensing Technology and Health, College of Chemistry, Central China Normal University, Wuhan 430079, P.R. China
| | - Hongye Yan
- Key Laboratory of Pesticide and Chemical Biology of Ministry of Education, International Joint Research Center for Intelligent Biosensing Technology and Health, College of Chemistry, Central China Normal University, Wuhan 430079, P.R. China
| | - Weiqing Xu
- Key Laboratory of Pesticide and Chemical Biology of Ministry of Education, International Joint Research Center for Intelligent Biosensing Technology and Health, College of Chemistry, Central China Normal University, Wuhan 430079, P.R. China
| | - Yu Wu
- Key Laboratory of Pesticide and Chemical Biology of Ministry of Education, International Joint Research Center for Intelligent Biosensing Technology and Health, College of Chemistry, Central China Normal University, Wuhan 430079, P.R. China
| | - Hengjia Wang
- Key Laboratory of Pesticide and Chemical Biology of Ministry of Education, International Joint Research Center for Intelligent Biosensing Technology and Health, College of Chemistry, Central China Normal University, Wuhan 430079, P.R. China
| | - Wenling Gu
- Key Laboratory of Pesticide and Chemical Biology of Ministry of Education, International Joint Research Center for Intelligent Biosensing Technology and Health, College of Chemistry, Central China Normal University, Wuhan 430079, P.R. China
| | - Chengzhou Zhu
- Key Laboratory of Pesticide and Chemical Biology of Ministry of Education, International Joint Research Center for Intelligent Biosensing Technology and Health, College of Chemistry, Central China Normal University, Wuhan 430079, P.R. China
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50
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Christensen SJ, Badino SF, Cavaleiro AM, Borch K, Westh P. Functional analysis of chimeric TrCel6A enzymes with different carbohydrate binding modules. Protein Eng Des Sel 2020; 32:401-409. [PMID: 32100026 DOI: 10.1093/protein/gzaa003] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2019] [Revised: 01/10/2019] [Accepted: 01/13/2019] [Indexed: 11/14/2022] Open
Abstract
The glycoside hydrolase (GH) family 6 is an important group of enzymes that constitute an essential part of industrial enzyme cocktails used to convert lignocellulose into fermentable sugars. In nature, enzymes from this family often have a carbohydrate binding module (CBM) from the CBM family 1. These modules are known to promote adsorption to the cellulose surface and influence enzymatic activity. Here, we have investigated the functional diversity of CBMs found within the GH6 family. This was done by constructing five chimeric enzymes based on the model enzyme, TrCel6A, from the soft-rot fungus Trichoderma reesei. The natural CBM of this enzyme was exchanged with CBMs from other GH6 enzymes originating from different cellulose degrading fungi. The chimeric enzymes were expressed in the same host and investigated in adsorption and quasi-steady-state kinetic experiments. Our results quantified functional differences of these phylogenetically distant binding modules. Thus, the partitioning coefficient for substrate binding varied 4-fold, while the maximal turnover (kcat) showed a 2-fold difference. The wild-type enzyme showed the highest cellulose affinity on all tested substrates and the highest catalytic turnover. The CBM from Serendipita indica strongly promoted the enzyme's ability to form productive complexes with sites on the substrate surface but showed lower turnover of the complex. We conclude that the CBM plays an important role for the functional differences between GH6 wild-type enzymes.
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Affiliation(s)
- Stefan Jarl Christensen
- Research Unit for Functional Biomaterials, Department of Science and Environment, Roskilde University, building 28B, DK-4000, Roskilde, Denmark
| | - Silke Flindt Badino
- Research Unit for Functional Biomaterials, Department of Science and Environment, Roskilde University, building 28B, DK-4000, Roskilde, Denmark
| | - Ana Mafalda Cavaleiro
- Research Unit for Functional Biomaterials, Department of Science and Environment, Roskilde University, building 28B, DK-4000, Roskilde, Denmark.,Novozymes A/S, Department of Enzyme Discovery, Rævehøjvej 32A, DK-2800 Kgs. Lyngby, Denmark
| | - Kim Borch
- Novozymes A/S, Department of Enzyme Discovery, Rævehøjvej 32A, DK-2800 Kgs. Lyngby, Denmark
| | - Peter Westh
- Department of Biotechnology and Biomedicine, Technical University of Denmark, building 224, DK-2800, Kgs. Lyngby, Denmark
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