1
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Feng J, Li H, Lu Y, Li R, Cavaco-Paulo A, Fu J. Non-ionic surfactant PEG: Enhanced cutinase-catalyzed hydrolysis of polyethylene terephthalate. Int J Biol Macromol 2024; 273:133049. [PMID: 38857727 DOI: 10.1016/j.ijbiomac.2024.133049] [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: 03/22/2024] [Revised: 05/16/2024] [Accepted: 06/07/2024] [Indexed: 06/12/2024]
Abstract
To enhance the enzymatic digestibility of polyethylene terephthalate (PET), which is highly oriented and crystallized, a polyethylene glycol (PEG) surfactant of varying molecular weights was utilized to improve the stability of mutant cutinase from Humicola insolens (HiC) and to increase the accessibility of the enzyme to the substrate. Leveraging the optimal conditions for HiC hydrolysis of PET, the introduction of 1 % w/v PEG significantly increased the yield of PET hydrolysis products. PEG600 was particularly effective, increasing the yield by 64.58 % compared to using HiC alone. Moreover, the mechanisms by which PEG600 and PEG6000 enhance enzyme digestion were extensively examined using circular dichroism and fluorescence spectroscopy. The results from CD and fluorescence analyses indicated that PEG alters the protein conformation, thereby affecting the catalytic effect of the enzyme. Moreover, PEG improved the affinity between HiC and PET by lowering the surface tension of the solution, substantially enhancing PET hydrolysis. This study suggests that PEG holds considerable promise as an enzyme protector, significantly aiding in the hydrophilic modification and degradation of PET in an environmentally friendly and sustainable manner.
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Affiliation(s)
- Jundan Feng
- Jiangsu Engineering Technology Research Centre for Functional Textiles, Jiangnan University, No.1800 Lihu Avenue, Wuxi, China
| | - Huimin Li
- Jiangsu Engineering Technology Research Centre for Functional Textiles, Jiangnan University, No.1800 Lihu Avenue, Wuxi, China
| | - Yuzheng Lu
- Jiangsu Engineering Technology Research Centre for Functional Textiles, Jiangnan University, No.1800 Lihu Avenue, Wuxi, China; Mechanical Engineering College, Tarim University, Alar, Xinjiang, China
| | - Rong Li
- Jiangsu Engineering Technology Research Centre for Functional Textiles, Jiangnan University, No.1800 Lihu Avenue, Wuxi, China
| | | | - Jiajia Fu
- Jiangsu Engineering Technology Research Centre for Functional Textiles, Jiangnan University, No.1800 Lihu Avenue, Wuxi, China.
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2
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Charlier C, Gavalda S, Grga J, Perrot L, Gabrielli V, Löhr F, Schörghuber J, Lichtenecker R, Arnal G, Marty A, Tournier V, Lippens G. Exploring the pH dependence of an improved PETase. Biophys J 2024; 123:1542-1552. [PMID: 38664965 PMCID: PMC11213969 DOI: 10.1016/j.bpj.2024.04.026] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2024] [Revised: 03/20/2024] [Accepted: 04/23/2024] [Indexed: 05/12/2024] Open
Abstract
Enzymatic recycling of plastic and especially of polyethylene terephthalate (PET) has shown great potential to reduce its negative impact on our society. PET hydrolases (PETases) have been optimized using rational design and machine learning, but the mechanistic details of the PET depolymerization process remain unclear. Belonging to the carboxylic-ester hydrolase family with a canonical Ser-His-Asp catalytic triad, their observed alkaline pH optimum is generally thought to be related to the protonation state of the catalytic His. Here, we explore this aspect in the context of LCCICCG, an optimized PETase, derived from the leaf-branch compost cutinase enzyme. We use NMR to identify the dominant tautomeric structure of the six histidines. Five show surprisingly low pKa values below 4.0, whereas the catalytic H242 in the active enzyme displays a pKa value that varies from 4.9 to 4.7 when temperatures increase from 30°C to 50°C. Whereas the hydrolytic activity of the enzyme toward a soluble substrate can be modeled by the corresponding protonation/deprotonation curve, an important discrepancy is found when the substrate is the solid plastic. This opens the way to further mechanistic understanding of the PETase activity and underscores the importance of studying the enzyme at the liquid-solid interface.
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Affiliation(s)
- Cyril Charlier
- Toulouse Biotechnology Institute (TBI), University of Toulouse, CNRS, INRAE, INSA Toulouse, Toulouse Cedex, France
| | - Sabine Gavalda
- Carbios, Parc Cataroux - Bâtiment B80, Clermont-Ferrand, France
| | - Jelena Grga
- Toulouse Biotechnology Institute (TBI), University of Toulouse, CNRS, INRAE, INSA Toulouse, Toulouse Cedex, France
| | - Laura Perrot
- Toulouse Biotechnology Institute (TBI), University of Toulouse, CNRS, INRAE, INSA Toulouse, Toulouse Cedex, France
| | - Valeria Gabrielli
- Toulouse Biotechnology Institute (TBI), University of Toulouse, CNRS, INRAE, INSA Toulouse, Toulouse Cedex, France
| | - Frank Löhr
- Institute of Biophysical Chemistry, Center for Biomolecular Magnetic Resonance, Goethe, University Frankfurt, Frankfurt am Main, Germany
| | - Julia Schörghuber
- Institute of Organic Chemistry, University of Vienna, Währingerstraße 38, Vienna, Austria
| | - Roman Lichtenecker
- Institute of Organic Chemistry, University of Vienna, Währingerstraße 38, Vienna, Austria; MAG-LAB, Vienna, Austria
| | - Grégory Arnal
- Carbios, Parc Cataroux - Bâtiment B80, Clermont-Ferrand, France
| | - Alain Marty
- Carbios, Parc Cataroux - Bâtiment B80, Clermont-Ferrand, France
| | | | - Guy Lippens
- Toulouse Biotechnology Institute (TBI), University of Toulouse, CNRS, INRAE, INSA Toulouse, Toulouse Cedex, France.
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3
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Bergeson AR, Silvera AJ, Alper HS. Bottlenecks in biobased approaches to plastic degradation. Nat Commun 2024; 15:4715. [PMID: 38830860 PMCID: PMC11148140 DOI: 10.1038/s41467-024-49146-8] [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: 07/29/2023] [Accepted: 05/23/2024] [Indexed: 06/05/2024] Open
Abstract
Plastic waste is an environmental challenge, but also presents a biotechnological opportunity as a unique carbon substrate. With modern biotechnological tools, it is possible to enable both recycling and upcycling. To realize a plastics bioeconomy, significant intrinsic barriers must be overcome using a combination of enzyme, strain, and process engineering. This article highlights advances, challenges, and opportunities for a variety of common plastics.
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Affiliation(s)
- Amelia R Bergeson
- McKetta Department of Chemical Engineering, The University of Texas at Austin, Austin, TX, USA
| | - Ashli J Silvera
- McKetta Department of Chemical Engineering, The University of Texas at Austin, Austin, TX, USA
| | - Hal S Alper
- McKetta Department of Chemical Engineering, The University of Texas at Austin, Austin, TX, USA.
- Institute for Cellular and Molecular Biology, The University of Texas at Austin, Austin, TX, USA.
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4
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Zarubin M, Andreev E, Kravchenko E, Pinaeva U, Nechaev A, Apel P. Developing tardigrade-inspired material: Track membranes functionalized with Dsup protein for cell-free DNA isolation. Biotechnol Prog 2024:e3478. [PMID: 38699905 DOI: 10.1002/btpr.3478] [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: 11/29/2023] [Revised: 04/09/2024] [Accepted: 04/24/2024] [Indexed: 05/05/2024]
Abstract
When developing functionalized biomaterials, the proteins from extremophilic organisms, in particular unique tardigrade disordered proteins, are of great value. The damage suppressor protein (Dsup), initially discovered in the tardigrade Ramazzottius varieornatus and found to be an efficient DNA protector under oxidative and irradiation stress, has been hypothesized to possess a good potential for the development of the material, which can isolate cell-free DNA. With this in mind, DNA-nonadsorbing polyethylene terephthalate track membranes have been functionalized using the Dsup protein via covalent bonding with glutaraldehyde. The filtration experiments have verified the ability of track membranes with the immobilized Dsup protein to adsorb cell-free DNA, with an accumulation capacity of 70 ± 19 mg m-2. The resulting track membrane-based biomaterial might be used in various devices for filtration and separation of cell-free DNA molecules from biological solutions and environmental samples, and also for their accumulation, storage, and further manipulation.
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Affiliation(s)
- Mikhail Zarubin
- Dzhelepov Laboratory of Nuclear Problems, International Intergovernmental Organization Joint Institute for Nuclear Research (DLNP JINR), Dubna, Russia
| | - Evgeny Andreev
- Flerov Laboratory of Nuclear Reactions, International Intergovernmental Organization Joint Institute for Nuclear Research (FLNR JINR), Dubna, Russia
| | - Elena Kravchenko
- Dzhelepov Laboratory of Nuclear Problems, International Intergovernmental Organization Joint Institute for Nuclear Research (DLNP JINR), Dubna, Russia
| | - Uliana Pinaeva
- Flerov Laboratory of Nuclear Reactions, International Intergovernmental Organization Joint Institute for Nuclear Research (FLNR JINR), Dubna, Russia
| | - Alexander Nechaev
- Flerov Laboratory of Nuclear Reactions, International Intergovernmental Organization Joint Institute for Nuclear Research (FLNR JINR), Dubna, Russia
| | - Pavel Apel
- Flerov Laboratory of Nuclear Reactions, International Intergovernmental Organization Joint Institute for Nuclear Research (FLNR JINR), Dubna, Russia
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5
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Kong D, Zhang H, Yuan Y, Wu J, Liu Z, Chen S, Zhang F, Wang L. Enhanced biodegradation activity toward polyethylene by fusion protein of anchor peptide and Streptomyces sp. strain K30 latex clearing protein. Int J Biol Macromol 2024; 264:130378. [PMID: 38428774 DOI: 10.1016/j.ijbiomac.2024.130378] [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: 06/01/2023] [Revised: 02/20/2024] [Accepted: 02/20/2024] [Indexed: 03/03/2024]
Abstract
Polyethylene is the most commonly used plastic product, and its biodegradation is a worldwide problem. Latex clearing protein derived from Streptomyces sp. strain K30 (LcpK30) has been reported to be able to break the carbon-carbon double bond inside oxidized polyethylene and is an effective biodegradation enzyme for polyethylene. However, the binding of the substrate to the enzyme was difficult due to the hydrophobic nature of polyethylene. Therefore, to further improve the efficiency of LcpK30, the effect of different anchor peptides on the binding capacity of LcpK30 to the substrate was screened in this study. The results of fluorescence confocal microscopy showed that the anchoring peptide LCI had the most significant improvement in effect and was finally selected for further application in a UV-irradiated PE degradation system. The degradation results showed that LCI was able to improve the degradation efficiency of LcpK30 by approximately 1.15 times in the presence of equimolar amounts of protein compared with wild-type. This study further improves the application of LcpK30 in the field of polyethylene degradation by modification.
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Affiliation(s)
- Demin Kong
- Key Laboratory of Industrial Biotechnology, Ministry of Education and School of Biotechnology, Jiangnan University, 1800 Lihu Avenue, Wuxi 214122, China; State Key Laboratory of Food Science and Resources, Jiangnan University, 1800 Lihu Avenue, Wuxi 214122, China; International Joint Laboratory on Food Safety, Jiangnan University, 1800 Lihu Avenue, Wuxi 214122, China
| | - Hui Zhang
- Key Laboratory of Industrial Biotechnology, Ministry of Education and School of Biotechnology, Jiangnan University, 1800 Lihu Avenue, Wuxi 214122, China; State Key Laboratory of Food Science and Resources, Jiangnan University, 1800 Lihu Avenue, Wuxi 214122, China; International Joint Laboratory on Food Safety, Jiangnan University, 1800 Lihu Avenue, Wuxi 214122, China
| | - Yuan Yuan
- Key Laboratory of Industrial Biotechnology, Ministry of Education and School of Biotechnology, Jiangnan University, 1800 Lihu Avenue, Wuxi 214122, China; State Key Laboratory of Food Science and Resources, Jiangnan University, 1800 Lihu Avenue, Wuxi 214122, China; International Joint Laboratory on Food Safety, Jiangnan University, 1800 Lihu Avenue, Wuxi 214122, China
| | - Jing Wu
- Key Laboratory of Industrial Biotechnology, Ministry of Education and School of Biotechnology, Jiangnan University, 1800 Lihu Avenue, Wuxi 214122, China; State Key Laboratory of Food Science and Resources, Jiangnan University, 1800 Lihu Avenue, Wuxi 214122, China; International Joint Laboratory on Food Safety, Jiangnan University, 1800 Lihu Avenue, Wuxi 214122, China
| | - Zhanzhi Liu
- Key Laboratory of Industrial Biotechnology, Ministry of Education and School of Biotechnology, Jiangnan University, 1800 Lihu Avenue, Wuxi 214122, China; State Key Laboratory of Food Science and Resources, Jiangnan University, 1800 Lihu Avenue, Wuxi 214122, China; International Joint Laboratory on Food Safety, Jiangnan University, 1800 Lihu Avenue, Wuxi 214122, China
| | - Sheng Chen
- Key Laboratory of Industrial Biotechnology, Ministry of Education and School of Biotechnology, Jiangnan University, 1800 Lihu Avenue, Wuxi 214122, China; State Key Laboratory of Food Science and Resources, Jiangnan University, 1800 Lihu Avenue, Wuxi 214122, China; International Joint Laboratory on Food Safety, Jiangnan University, 1800 Lihu Avenue, Wuxi 214122, China
| | - Fengshan Zhang
- Shandong Huatai Paper Co., Ltd. and Shandong Yellow Triangle Biotechnology Industry Research Institute Co. Ltd, Dongying 257335, China
| | - Lei Wang
- Key Laboratory of Industrial Biotechnology, Ministry of Education and School of Biotechnology, Jiangnan University, 1800 Lihu Avenue, Wuxi 214122, China; State Key Laboratory of Food Science and Resources, Jiangnan University, 1800 Lihu Avenue, Wuxi 214122, China; International Joint Laboratory on Food Safety, Jiangnan University, 1800 Lihu Avenue, Wuxi 214122, China.
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6
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Clark R, Shaver MP. Depolymerization within a Circular Plastics System. Chem Rev 2024; 124:2617-2650. [PMID: 38386877 PMCID: PMC10941197 DOI: 10.1021/acs.chemrev.3c00739] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2023] [Revised: 01/18/2024] [Accepted: 02/08/2024] [Indexed: 02/24/2024]
Abstract
The societal importance of plastics contrasts with the carelessness with which they are disposed. Their superlative properties lead to economic and environmental efficiency, but the linearity of plastics puts the climate, human health, and global ecosystems at risk. Recycling is fundamental to transitioning this linear model into a more sustainable, circular economy. Among recycling technologies, chemical depolymerization offers a route to virgin quality recycled plastics, especially when valorizing complex waste streams poorly served by mechanical methods. However, chemical depolymerization exists in a complex and interlinked system of end-of-life fates, with the complementarity of each approach key to environmental, economic, and societal sustainability. This review explores the recent progress made into the depolymerization of five commercial polymers: poly(ethylene terephthalate), polycarbonates, polyamides, aliphatic polyesters, and polyurethanes. Attention is paid not only to the catalytic technologies used to enhance depolymerization efficiencies but also to the interrelationship with other recycling technologies and to the systemic constraints imposed by a global economy. Novel polymers, designed for chemical depolymerization, are also concisely reviewed in terms of their underlying chemistry and potential for integration with current plastic systems.
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Affiliation(s)
- Robbie
A. Clark
- Department
of Materials, School of Natural Sciences, University of Manchester, Manchester M13 9PL, United
Kingdom
- Sustainable
Materials Innovation Hub, Henry Royce Institute, University of Manchester, Manchester M13 9PL, United
Kingdom
| | - Michael P. Shaver
- Department
of Materials, School of Natural Sciences, University of Manchester, Manchester M13 9PL, United
Kingdom
- Sustainable
Materials Innovation Hub, Henry Royce Institute, University of Manchester, Manchester M13 9PL, United
Kingdom
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7
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Rennison AP, Nousi A, Westh P, Marie R, Møller MS. Unveiling PET Hydrolase Surface Dynamics through Fluorescence Microscopy. Chembiochem 2024; 25:e202300661. [PMID: 38224131 DOI: 10.1002/cbic.202300661] [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: 09/27/2023] [Revised: 12/21/2023] [Accepted: 01/13/2024] [Indexed: 01/16/2024]
Abstract
PET hydrolases are an emerging class of enzymes that are being heavily researched for their use in bioprocessing polyethylene terephthalate (PET). While work has been done in studying the binding of PET oligomers to the active site of these enzymes, the dynamics of PET hydrolases binding to a bulk PET surface is an unexplored area. Here, methods were developed for total internal reflection fluorescence (TIRF) microscopy and fluorescence recovery after photobleaching (FRAP) microscopy to study the adsorption and desorption dynamics of these proteins onto a PET surface. TIRF microscopy was employed to measure both on and off rates of two of the most commonly studied PET hydrolases, PHL7 and LCC, on a PET surface. It was found that these proteins have a much slower off rates on the order of 10-3 s-1 , comparable to non-productive binding in enzymes such as cellulose. In combination with FRAP microscopy, a dynamic model is proposed in which adsorption and desorption dominates over lateral diffusion over the surface. The results of this study could have implications for the future engineering of PET hydrolases, either to target them to a PET surface or to modulate interaction with their substrate.
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Affiliation(s)
- A P Rennison
- Department of Biotechnology and Biomedicine, Technical University of Denmark, 2800, Kongens Lyngby, Denmark
| | - A Nousi
- Department of Health Technology, Technical University of Denmark, 2800, Kongens Lyngby, Denmark
| | - P Westh
- Department of Biotechnology and Biomedicine, Technical University of Denmark, 2800, Kongens Lyngby, Denmark
| | - R Marie
- Department of Health Technology, Technical University of Denmark, 2800, Kongens Lyngby, Denmark
| | - M S Møller
- Department of Biotechnology and Biomedicine, Technical University of Denmark, 2800, Kongens Lyngby, Denmark
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8
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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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9
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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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10
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Determinants for an Efficient Enzymatic Catalysis in Poly(Ethylene Terephthalate) Degradation. Catalysts 2023. [DOI: 10.3390/catal13030591] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/18/2023] Open
Abstract
The enzymatic degradation of the recalcitrant poly(ethylene terephthalate) (PET) has been an important biotechnological goal. The present review focuses on the state of the art in enzymatic degradation of PET, and the challenges ahead. This review covers (i) enzymes acting on PET, (ii) protein improvements through selection or engineering, (iii) strategies to improve biocatalyst–polymer interaction and monomer yields. Finally, this review discusses critical points on PET degradation, and their related experimental aspects, that include the control of physicochemical parameters. The search for, and engineering of, PET hydrolases, have been widely studied to achieve this, and several examples are discussed here. Many enzymes, from various microbial sources, have been studied and engineered, but recently true PET hydrolases (PETases), active at moderate temperatures, were reported. For a circular economy process, terephtalic acid (TPA) production is critical. Some thermophilic cutinases and engineered PETases have been reported to release terephthalic acid in significant amounts. Some bottlenecks in enzyme performance are discussed, including enzyme activity, thermal stability, substrate accessibility, PET microstructures, high crystallinity, molecular mass, mass transfer, and efficient conversion into reusable fragments.
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11
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Mrigwani A, Pitaliya M, Kaur H, Kasilingam B, Thakur B, Guptasarma P. Rational mutagenesis of Thermobifida fusca cutinase to modulate the enzymatic degradation of polyethylene terephthalate. Biotechnol Bioeng 2023; 120:674-686. [PMID: 36514261 DOI: 10.1002/bit.28305] [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: 07/08/2022] [Revised: 12/08/2022] [Accepted: 12/11/2022] [Indexed: 12/15/2022]
Abstract
Thermobifida fusca cutinase (TfCut2) is a carboxylesterase (CE) which degrades polyethylene terephthalate (PET) as well as its degradation intermediates [such as oligoethylene terephthalate (OET), or bis-/mono-hydroxyethyl terephthalate (BHET/MHET)] into terephthalic acid (TPA). Comparisons of the surfaces of certain CEs (including TfCut2) were combined with docking and molecular dynamics simulations involving 2HE-(MHET)3, a three-terephthalate OET, to support the rational design of 22 variants with potential for improved generation of TPA from PET, comprising 15 single mutants (D12L, E47F, G62A, L90A, L90F, H129W, W155F, ΔV164, A173C, H184A, H184S, F209S, F209I, F249A, and F249R), 6 double mutants [H129W/T136S, A173C/A206C, A173C/A210C, G62A/L90F, G62A/F209I, and G62A/F249R], and 1 triple mutant [G62A/F209I/F249R]. Of these, nine displayed no activity, three displayed decreased activity, three displayed comparable activity, and seven displayed increased (~1.3- to ~7.2-fold) activity against solid PET, while all variants displayed activity against BHET. Of the variants that displayed increased activity against PET, four displayed more activity than G62A, the most-active mutant of TfCut2 known till date. Of these four, three displayed even more activity than LCC (G62A/F209I, G62A/F249R, and G62A/F209I/F249R), a CE known to be ~5-fold more active than wild-type TfCut2. These improvements derived from changes in PET binding and not changes in catalytic efficiency.
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Affiliation(s)
- Arpita Mrigwani
- Centre for Protein Science, Design and Engineering (CPSDE) and Hyperthermophile Enzyme Hydrolase Research Centre (HEHRC), Department of Biological Sciences, Indian Institute of Science Education and Research (IISER) Mohali, SAS Nagar (Mohali), Punjab, India
| | - Madhav Pitaliya
- Centre for Protein Science, Design and Engineering (CPSDE) and Hyperthermophile Enzyme Hydrolase Research Centre (HEHRC), Department of Biological Sciences, Indian Institute of Science Education and Research (IISER) Mohali, SAS Nagar (Mohali), Punjab, India
| | - Harman Kaur
- Centre for Protein Science, Design and Engineering (CPSDE) and Hyperthermophile Enzyme Hydrolase Research Centre (HEHRC), Department of Biological Sciences, Indian Institute of Science Education and Research (IISER) Mohali, SAS Nagar (Mohali), Punjab, India
| | - Bharathraj Kasilingam
- Centre for Protein Science, Design and Engineering (CPSDE) and Hyperthermophile Enzyme Hydrolase Research Centre (HEHRC), Department of Biological Sciences, Indian Institute of Science Education and Research (IISER) Mohali, SAS Nagar (Mohali), Punjab, India
| | - Bhishem Thakur
- Centre for Protein Science, Design and Engineering (CPSDE) and Hyperthermophile Enzyme Hydrolase Research Centre (HEHRC), Department of Biological Sciences, Indian Institute of Science Education and Research (IISER) Mohali, SAS Nagar (Mohali), Punjab, India
| | - Purnananda Guptasarma
- Centre for Protein Science, Design and Engineering (CPSDE) and Hyperthermophile Enzyme Hydrolase Research Centre (HEHRC), Department of Biological Sciences, Indian Institute of Science Education and Research (IISER) Mohali, SAS Nagar (Mohali), Punjab, India
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12
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Schubert S, Schaller K, Bååth JA, Hunt C, Borch K, Jensen K, Brask J, Westh P. Reaction Pathways for the Enzymatic Degradation of Poly(Ethylene Terephthalate): What Characterizes an Efficient PET-Hydrolase? Chembiochem 2023; 24:e202200516. [PMID: 36399069 PMCID: PMC10108200 DOI: 10.1002/cbic.202200516] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2022] [Revised: 11/16/2022] [Accepted: 11/16/2022] [Indexed: 11/19/2022]
Abstract
Bioprocessing of polyester waste has emerged as a promising tool in the quest for a cyclic plastic economy. One key step is the enzymatic breakdown of the polymer, and this entails a complicated pathway with substrates, intermediates, and products of variable size and solubility. We have elucidated this pathway for poly(ethylene terephthalate) (PET) and four enzymes. Specifically, we combined different kinetic measurements and a novel stochastic model and found that the ability to hydrolyze internal bonds in the polymer (endo-lytic activity) was a key parameter for overall enzyme performance. Endo-lytic activity promoted the release of soluble PET fragments with two or three aromatic rings, which, in turn, were broken down with remarkable efficiency (kcat /KM values of about 105 M-1 s-1 ) in the aqueous bulk. This meant that approximatly 70 % of the final, monoaromatic products were formed via soluble di- or tri-aromatic intermediates.
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Affiliation(s)
- Sune Schubert
- Department of Biotechnology and Biomedicine, Technical University of Denmark, Søltofts Plads, 2800 Kgs., Lyngby, Denmark
| | - Kay Schaller
- Department of Biotechnology and Biomedicine, Technical University of Denmark, Søltofts Plads, 2800 Kgs., Lyngby, Denmark
| | | | - Cameron Hunt
- 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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13
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Hayes HC, Luk LYP. Investigating the effects of cyclic topology on the performance of a plastic degrading enzyme for polyethylene terephthalate degradation. Sci Rep 2023; 13:1267. [PMID: 36690710 PMCID: PMC9870871 DOI: 10.1038/s41598-023-27780-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2022] [Accepted: 01/09/2023] [Indexed: 01/24/2023] Open
Abstract
Agitation is a commonly encountered stress for enzymes during all stages of production and application, but investigations that aim to improve their tolerance using topological engineering have yet to be reported. Here, the plastic-degrading enzyme IsPETase was cyclized in a range of topologies including a cyclic monomer, cyclic dimer and catenane using SpyTag/SpyCatcher technologies, and their tolerance towards different stresses including mechanical agitation was investigated. The cyclic dimer and catenane topologies were less susceptible to agitation-induced inactivation resulting in enhancement of polyethylene terephthalate (PET) degradation. While contrary to conventional belief, cyclic topologies did not improve tolerance of IsPETase towards heat or proteolytic treatment, the close proximity of active sites in the dimeric and catenane variants was found to enhance PET conversion into small soluble products. Together, these findings illustrate that it is worthwhile to explore the topology engineering of enzymes used in heterogeneous catalysis as it improves factors that are often overlooked in homogeneous catalysis studies.
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Affiliation(s)
- Heather C Hayes
- School of Chemistry, Cardiff University Main Building, Park Place, Cardiff, CF10 3AT, UK
- Cardiff Catalysis Institute, Cardiff University Main Building, Park Place, Cardiff, CF10 3AT, UK
| | - Louis Y P Luk
- School of Chemistry, Cardiff University Main Building, Park Place, Cardiff, CF10 3AT, UK.
- Cardiff Catalysis Institute, Cardiff University Main Building, Park Place, Cardiff, CF10 3AT, UK.
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14
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Tarazona NA, Wei R, Brott S, Pfaff L, Bornscheuer UT, Lendlein A, Machatschek R. Rapid depolymerization of poly(ethylene terephthalate) thin films by a dual-enzyme system and its impact on material properties. CHEM CATALYSIS 2022; 2:3573-3589. [PMID: 37350932 PMCID: PMC10284027 DOI: 10.1016/j.checat.2022.11.004] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/21/2022] [Revised: 10/17/2022] [Accepted: 11/04/2022] [Indexed: 06/24/2023]
Abstract
Enzymatic hydrolysis holds great promise for plastic waste recycling and upcycling. The interfacial catalysis mode, and the variability of polymer specimen properties under different degradation conditions, add to the complexity and difficulty of understanding polymer cleavage and engineering better biocatalysts. We present a systemic approach to studying the enzyme-catalyzed surface erosion of poly(ethylene terephthalate) (PET) while monitoring/controlling operating conditions in real time with simultaneous detection of mass loss and changes in viscoelastic behavior. PET nanofilms placed on water showed a porous morphology and a thickness-dependent glass transition temperature (Tg) between 40°C and 44°C, which is >20°C lower than the Tg of bulk amorphous PET. Hydrolysis by a dual-enzyme system containing thermostabilized variants of Ideonella sakaiensis PETase and MHETase resulted in a maximum depolymerization of 70% in 1 h at 50°C. We demonstrate that increased accessible surface area, amorphization, and Tg reduction speed up PET degradation while simultaneously lowering the threshold for degradation-induced crystallization.
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Affiliation(s)
- Natalia A. Tarazona
- Institute of Active Polymers, Helmholtz-Zentrum Hereon, Kantstraße 55, 14513 Teltow, Germany
| | - Ren Wei
- Institute of Biochemistry, University of Greifswald, Felix-Hausdorff-Straße 8, 17489 Greifswald, Germany
| | - Stefan Brott
- Institute of Biochemistry, University of Greifswald, Felix-Hausdorff-Straße 8, 17489 Greifswald, Germany
| | - Lara Pfaff
- Institute of Biochemistry, University of Greifswald, Felix-Hausdorff-Straße 8, 17489 Greifswald, Germany
| | - Uwe T. Bornscheuer
- Institute of Biochemistry, University of Greifswald, Felix-Hausdorff-Straße 8, 17489 Greifswald, Germany
| | - Andreas Lendlein
- Institute of Active Polymers, Helmholtz-Zentrum Hereon, Kantstraße 55, 14513 Teltow, Germany
- Institute of Chemistry, University of Potsdam, Karl-Liebknecht-Straße 24-25, 14469 Potsdam, Germany
| | - Rainhard Machatschek
- Institute of Active Polymers, Helmholtz-Zentrum Hereon, Kantstraße 55, 14513 Teltow, Germany
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15
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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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16
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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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17
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Pirillo V, Orlando M, Tessaro D, Pollegioni L, Molla G. An Efficient Protein Evolution Workflow for the Improvement of Bacterial PET Hydrolyzing Enzymes. Int J Mol Sci 2021; 23:ijms23010264. [PMID: 35008691 PMCID: PMC8745736 DOI: 10.3390/ijms23010264] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2021] [Revised: 12/23/2021] [Accepted: 12/24/2021] [Indexed: 12/23/2022] Open
Abstract
Enzymatic degradation is a promising green approach to bioremediation and recycling of the polymer poly(ethylene terephthalate) (PET). In the past few years, several PET-hydrolysing enzymes (PHEs) have been discovered, and new variants have been evolved by protein engineering. Here, we report on a straightforward workflow employing semi-rational protein engineering combined to a high-throughput screening of variant libraries for their activity on PET nanoparticles. Using this approach, starting from the double variant W159H/S238F of Ideonella sakaiensis 201-F6 PETase, the W159H/F238A-ΔIsPET variant, possessing a higher hydrolytic activity on PET, was identified. This variant was stabilized by introducing two additional known substitutions (S121E and D186H) generating the TS-ΔIsPET variant. By using 0.1 mg mL−1 of TS-ΔIsPET, ~10.6 mM of degradation products were produced in 2 days from 9 mg mL−1 PET microparticles (~26% depolymerization yield). Indeed, TS-ΔIsPET allowed a massive degradation of PET nanoparticles (>80% depolymerization yield) in 1.5 h using only 20 μg of enzyme mL−1. The rationale underlying the effect on the catalytic parameters due to the F238A substitution was studied by enzymatic investigation and molecular dynamics/docking analysis. The present workflow is a well-suited protocol for the evolution of PHEs to help generate an efficient enzymatic toolbox for polyester degradation.
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Affiliation(s)
- Valentina Pirillo
- “The Protein Factory 2.0”, Dipartimento di Biotecnologie e Scienze della Vita, Università degli Studi dell’Insubria, Via J.H. Dunant 3, 21100 Varese, Italy; (V.P.); (M.O.)
| | - Marco Orlando
- “The Protein Factory 2.0”, Dipartimento di Biotecnologie e Scienze della Vita, Università degli Studi dell’Insubria, Via J.H. Dunant 3, 21100 Varese, Italy; (V.P.); (M.O.)
| | - Davide Tessaro
- Dipartimento di Chimica, Materiali e Ingegneria Chimica “Giulio Natta”, Politecnico di Milano, p.za L. da Vinci 32, 20133 Milano, Italy;
| | - Loredano Pollegioni
- “The Protein Factory 2.0”, Dipartimento di Biotecnologie e Scienze della Vita, Università degli Studi dell’Insubria, Via J.H. Dunant 3, 21100 Varese, Italy; (V.P.); (M.O.)
- Correspondence: (L.P.); (G.M.)
| | - Gianluca Molla
- “The Protein Factory 2.0”, Dipartimento di Biotecnologie e Scienze della Vita, Università degli Studi dell’Insubria, Via J.H. Dunant 3, 21100 Varese, Italy; (V.P.); (M.O.)
- Correspondence: (L.P.); (G.M.)
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