1
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Miao R, Xu G, Ding Y, Ding Z, Woodard J, Tu T, Luo H, Wu N, Yao B, Guan F, Tian J. Engineering dual-functional and thermophilic BMHETase for efficient degradation of polyethylene terephthalate. BIORESOURCE TECHNOLOGY 2024:131556. [PMID: 39357610 DOI: 10.1016/j.biortech.2024.131556] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/08/2024] [Revised: 09/15/2024] [Accepted: 09/29/2024] [Indexed: 10/04/2024]
Abstract
Polyethylene terephthalate (PET) biodegradation is hindered by the intermediates bis (2-hydroxyethyl) terephthalate (BHET) and mono (2-hydroxyethyl) terephthalate (MHET). BMHETase, a thermophilic hydrolase identified from the UniParc database, exhibits degradation activity towards both BHET and MHET. BMHETase showed higher activity on BHET than LCCICCG and FASTPETase at temperatures ranging from 50 to 70℃. To enhance its activity in degrading MHET, BMHETase was engineered to mimic Ideonella sakaiensis MHETase. The resulting 6-point mutant's activities on MHET and BHET were 8 and 2 times those of the WT, with both optimal temperatures increased by 5℃. This enhancement may be attributed to the BMHETase6M's intensified binding ability with MHET and enlarged binding pocket. When combined with LCCICCG, BMHETase6M achieved complete degradation of MHET in PET films to terephthalic acid, indicating broad application potential. These findings suggest that BMHETase6M holds promise as a candidate for enhancing PET biodegradation efficiency and plastic waste management.
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Affiliation(s)
- Ruiju Miao
- State Key Laboratory of Animal Nutrition and Feeding, Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, Beijing 100193, China
| | - Guoshun Xu
- State Key Laboratory of Animal Nutrition and Feeding, Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, Beijing 100193, China
| | - Yekun Ding
- National Key Laboratory of Agricultural Microbiology, Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, Beijing 100081, China
| | - Zundan Ding
- National Key Laboratory of Agricultural Microbiology, Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, Beijing 100081, China.
| | - Jaie Woodard
- Department of Biomedical Engineering, University of Michigan, Ann Arbor, MI 48109, USA.
| | - Tao Tu
- State Key Laboratory of Animal Nutrition and Feeding, Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, Beijing 100193, China.
| | - Huiying Luo
- State Key Laboratory of Animal Nutrition and Feeding, Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, Beijing 100193, China.
| | - Ningfeng Wu
- National Key Laboratory of Agricultural Microbiology, Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, Beijing 100081, China.
| | - Bin Yao
- State Key Laboratory of Animal Nutrition and Feeding, Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, Beijing 100193, China.
| | - Feifei Guan
- National Key Laboratory of Agricultural Microbiology, Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, Beijing 100081, China.
| | - Jian Tian
- State Key Laboratory of Animal Nutrition and Feeding, Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, Beijing 100193, China; National Key Laboratory of Agricultural Microbiology, Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, Beijing 100081, China.
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2
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Chen SQ, Huang QS, Li Y, Wu J, Chen S, Yan ZF. Targeted aggregation of PETase towards surface of Stenotrophomonas pavanii for degradation of PET microplastics. JOURNAL OF HAZARDOUS MATERIALS 2024; 480:135895. [PMID: 39312844 DOI: 10.1016/j.jhazmat.2024.135895] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/02/2024] [Revised: 09/04/2024] [Accepted: 09/17/2024] [Indexed: 09/25/2024]
Abstract
Polyethylene terephthalate (PET) is one of the most widely used plastics, but its fragmentation into microplastics poses significant environmental challenges. The recycling of PET microplastics is hindered by their low solubility and widespread dispersion in the environment, making microbial in-situ degradation a promising solution. However, existing PET-degrading strains exhibited the limited effectiveness, primarily due to the diffusion of secreted hydrolases away from the PET surface. In this study, Stenotrophomonas pavanii JWG-G1 was engineered to achieve the targeted aggregation of PET hydrolase PETase on the cell surface by fusing it with an endogenous anchor protein. This approach aims to maximise the local concentration of PETase around PET, thereby increasing the overall rate of PET degradation. The PETase surface-aggregated system, S. pavanii/PaL-PETase, demonstrated the highest degradation efficiency, achieving 63.3 % degradation of low-crystallinity PET (lcPET) and 27.3 % degradation of high-crystallinity PET bottles (hcPET) at 30 °C. This represents the highest degradation rate reported for a displayed whole-cell system at ambient temperature. Furthermore, this system exhibited broad-spectrum degradation activity against various polyesters. These findings suggest that this system offers a promising, eco-friendly solution to PET and other polyester pollution, with potential implications for environmental bioremediation strategies.
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Affiliation(s)
- Si-Qi Chen
- School of Biotechnology and Key Laboratory of Industrial Biotechnology Ministry of Education, Jiangnan University, 1800 Lihu Avenue, Wuxi 214122, China
| | - Qing-Song Huang
- School of Biotechnology and Key Laboratory of Industrial Biotechnology Ministry of Education, Jiangnan University, 1800 Lihu Avenue, Wuxi 214122, China
| | - Yang Li
- School of Biotechnology and Key Laboratory of Industrial Biotechnology Ministry of Education, Jiangnan University, 1800 Lihu Avenue, Wuxi 214122, China
| | - Jing Wu
- School of Biotechnology and Key Laboratory of Industrial Biotechnology Ministry of Education, Jiangnan University, 1800 Lihu Avenue, Wuxi 214122, China; National Center of Technology Innovation for Dairy, Hohhot, China
| | - Sheng Chen
- School of Biotechnology and Key Laboratory of Industrial Biotechnology Ministry of Education, Jiangnan University, 1800 Lihu Avenue, Wuxi 214122, China.
| | - Zheng-Fei Yan
- School of Biotechnology and Key Laboratory of Industrial Biotechnology Ministry of Education, Jiangnan University, 1800 Lihu Avenue, Wuxi 214122, China.
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3
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Ogura Y, Hashino Y, Nakamura A. Direct Screening of PET Hydrolase Activity in Culture Medium Based on Turbidity Reduction. ACS OMEGA 2024; 9:34151-34160. [PMID: 39130604 PMCID: PMC11307985 DOI: 10.1021/acsomega.4c05488] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/12/2024] [Revised: 07/12/2024] [Accepted: 07/15/2024] [Indexed: 08/13/2024]
Abstract
The development of an efficient screening method for the activity of PET-degrading enzymes represents a significant technological advance in the field of enzyme research, with the potential to facilitate the advancement of enzymes for PET recycling. By examining the stable conditions of PET suspension and enzyme production conditions, we developed a method to quantify PET-degrading enzyme activity in E. coli culture medium using turbidity reduction as an indicator. High PET concentration or ionic strength caused aggregation of PET, and the best condition for activity detection was 0.5 mg mL-1 PET in 50 mM sodium phosphate pH 7.0. Preculture of E. coli increased the purity of enzyme secreted in medium. To evaluate the screening method, 720 colonies of the PET2-7M-H229X-F233X mutant library were analyzed and three candidates of high-activity mutants were obtained. The thermostability of the mutants could also be easily measured by measuring the residual activity after heat treatment. The H229T-F233M mutant showed 3.4 times higher degradation rate against PET film than the template enzyme at the initial time. The molecular dynamics simulation implied that the F233M mutation makes space for making an α helix and that the H229T mutation resolved the steric hindrance with Trp199. These mutations were speculated to change the angle of the Trp199 side chain of PET2 to an angle similar to that of the Trp185 of IsPETase, making it suitable for PET binding to the active center. Screening of activity using PET suspensions is compatible with robotic automation and is expected to be useful for validating computationally predicted mutations.
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Affiliation(s)
- Yui Ogura
- Department
of Agriculture, Graduate School of Integrated Science and Technology, Shizuoka University, 836 Ohya, Suruga-ku, Shizuoka 422-8529, Japan
| | - Yoshihito Hashino
- Department
of Agriculture, Graduate School of Integrated Science and Technology, Shizuoka University, 836 Ohya, Suruga-ku, Shizuoka 422-8529, Japan
| | - Akihiko Nakamura
- Department
of Applied Life Sciences, Faculty of Agriculture, Shizuoka University, 836 Ohya, Suruga-ku, Shizuoka 422-8529, Japan
- Research
Institute of Green Science and Technology, Shizuoka University, 836 Ohya, Suruga-ku, Shizuoka 422-8529, Japan
- Shizuoka
Institute for the Study of Marine Biology and Chemistry, Shizuoka, Shizuoka 422-8529, Japan
- Institute
for Molecular Science, National Institutes of Natural Sciences, 5-1 Higashiyama Myodaijicho, Okazaki, Aichi 444-8787, Japan
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4
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Zheng Y, Zhang J, You S, Lin W, Su R, Qi W. Efficient thermophilic polyethylene terephthalate hydrolase enhanced by cross correlation-based accumulated mutagenesis strategy. BIORESOURCE TECHNOLOGY 2024; 406:130929. [PMID: 38838832 DOI: 10.1016/j.biortech.2024.130929] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/27/2024] [Revised: 05/22/2024] [Accepted: 06/02/2024] [Indexed: 06/07/2024]
Abstract
Polyethylene terephthalate (PET) has caused significant pollution issues. Compared to chemical degradation with high energy consumption and cost, enzymatic degradation offers a sustainable solution for PET waste recycling. However, the hydrolytic activity of current PET hydrolases still requires improvement. In this study, a cross-correlation-based accumulated mutagenesis (CAM) strategy was developed to enhance the hydrolysis activity. By mitigating epistatic effect and combinational mutations, we achieved a highly active variant LCC-YGA (H183Y/L124G/S29A) with 2.1-fold hydrolytic activity on amorphous PET films of LCC-ICCG. Conformational analysis elucidated how the introduction of distal mutations enhanced activity. The dynamic correlation among different regions facilitated a synergistic effect, enhancing binding pocket flexibility through remote interactions. Totally, this work offers novel insights and methods for PET hydrolases engineering and provides an efficient enzyme for PET degradation and recycling.
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Affiliation(s)
- Yunxin Zheng
- State Key Laboratory of Chemical Engineering, School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072, PR China
| | - Jiaxing Zhang
- State Key Laboratory of Chemical Engineering, School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072, PR China
| | - Shengping You
- State Key Laboratory of Chemical Engineering, School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072, PR China
| | - Wei Lin
- State Key Laboratory of Chemical Engineering, School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072, PR China
| | - Rongxin Su
- State Key Laboratory of Chemical Engineering, School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072, PR China; Collaborative Innovation Centre of Chemical Science and Engineering (Tianjin), Tianjin 300072, PR China; Tianjin Key Laboratory of Membrane Science and Desalination Technology, Tianjin University, Tianjin 300072, PR China
| | - Wei Qi
- State Key Laboratory of Chemical Engineering, School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072, PR China; Collaborative Innovation Centre of Chemical Science and Engineering (Tianjin), Tianjin 300072, PR China; Tianjin Key Laboratory of Membrane Science and Desalination Technology, Tianjin University, Tianjin 300072, PR China.
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5
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Han Z, Nina MRH, Zhang X, Huang H, Fan D, Bai Y. Discovery and characterization of two novel polyethylene terephthalate hydrolases: One from a bacterium identified in human feces and one from the Streptomyces genus. JOURNAL OF HAZARDOUS MATERIALS 2024; 472:134532. [PMID: 38749251 DOI: 10.1016/j.jhazmat.2024.134532] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/24/2023] [Revised: 05/01/2024] [Accepted: 05/02/2024] [Indexed: 05/30/2024]
Abstract
Polyethylene terephthalate (PET) is widely used for various industrial applications. However, owing to its extremely slow breakdown rate, PET accumulates as plastic trash, which negatively affects the environment and human health. Here, we report two novel PET hydrolases: PpPETase from Pseudomonas paralcaligenes MRCP1333, identified in human feces, and ScPETase from Streptomyces calvus DSM 41452. These two enzymes can decompose various PET materials, including semicrystalline PET powders (Cry-PET) and low-crystallinity PET films (gf-PET). By structure-guided engineering, two variants, PpPETaseY239R/F244G/Y250G and ScPETaseA212C/T249C/N195H/N243K were obtained that decompose Cry-PET 3.1- and 1.9-fold faster than their wild-type enzymes, respectively. The co-expression of ScPETase and mono-(2-hydroxyethyl) terephthalate hydrolase from Ideonella sakaiensis (IsMHETase) resulted in 1.4-fold more degradation than the single enzyme system. This engineered strain degraded Cry-PET and gf-PET by more than 40% and 6%, respectively, after 30 d. The concentrations of terephthalic acid (TPA) in the Cry-PET and gf-PET degradation products were 37.7% and 25.6%, respectively. The discovery of these two novel PET hydrolases provides opportunities to create more powerful biocatalysts for PET biodegradation.
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Affiliation(s)
- Zhengyang Han
- State Key Laboratory of Bioreactor Engineering, Shanghai Collaborative Innovation Center for Biomanufacturing, East China University of Science and Technology, Shanghai 200237, China
| | - Mario Roque Huanca Nina
- State Key Laboratory of Bioreactor Engineering, Shanghai Collaborative Innovation Center for Biomanufacturing, East China University of Science and Technology, Shanghai 200237, China
| | - Xiaoyan Zhang
- State Key Laboratory of Bioreactor Engineering, Shanghai Collaborative Innovation Center for Biomanufacturing, East China University of Science and Technology, Shanghai 200237, China
| | - Hanyao Huang
- State Key Laboratory of Bioreactor Engineering, Shanghai Collaborative Innovation Center for Biomanufacturing, East China University of Science and Technology, Shanghai 200237, China
| | - Daidi Fan
- Shaanxi R&D Centre of Biomaterials and Fermentation Engineering, School of Chemical Engineering, Northwest University, Xi'an, Shaanxi 710069, China
| | - Yunpeng Bai
- State Key Laboratory of Bioreactor Engineering, Shanghai Collaborative Innovation Center for Biomanufacturing, East China University of Science and Technology, Shanghai 200237, China.
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6
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Kawai F, Iizuka R, Kawabata T. Engineered polyethylene terephthalate hydrolases: perspectives and limits. Appl Microbiol Biotechnol 2024; 108:404. [PMID: 38953996 PMCID: PMC11219463 DOI: 10.1007/s00253-024-13222-2] [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: 02/09/2024] [Revised: 06/03/2024] [Accepted: 06/04/2024] [Indexed: 07/04/2024]
Abstract
Polyethylene terephthalate (PET) is a major component of plastic waste. Enzymatic PET hydrolysis is the most ecofriendly recycling technology. The biorecycling of PET waste requires the complete depolymerization of PET to terephthalate and ethylene glycol. The history of enzymatic PET depolymerization has revealed two critical issues for the industrial depolymerization of PET: industrially available PET hydrolases and pretreatment of PET waste to make it susceptible to full enzymatic hydrolysis. As none of the wild-type enzymes can satisfy the requirements for industrialization, various mutational improvements have been performed, through classical technology to state-of-the-art computational/machine-learning technology. Recent engineering studies on PET hydrolases have brought a new insight that flexibility of the substrate-binding groove may improve the efficiency of PET hydrolysis while maintaining sufficient thermostability, although the previous studies focused only on enzymatic thermostability above the glass transition temperature of PET. Industrial biorecycling of PET waste is scheduled to be implemented, using micronized amorphous PET. Next stage must be the development of PET hydrolases that can efficiently degrade crystalline parts of PET and expansion of target PET materials, not only bottles but also textiles, packages, and microplastics. This review discusses the current status of PET hydrolases, their potential applications, and their profespectal goals. KEY POINTS: • PET hydrolases must be thermophilic, but their operation must be below 70 °C • Classical and state-of-the-art engineering approaches are useful for PET hydrolases • Enzyme activity on crystalline PET is most expected for future PET biorecycling.
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Affiliation(s)
- Fusako Kawai
- Graduate School of Environmental and Life Sciences, Okayama University, 1-1-1 Tsushima-Naka, Kita-Ku, Okayama, 700-8530, Japan.
| | - Ryo Iizuka
- Graduate School of Science, The University of Tokyo, 7-3-1 Hongo, Bunkyo-Ku, Tokyo, 113-0033, Japan
| | - Takeshi Kawabata
- Graduate School of Information Sciences, Tohoku University, Aoba 6-3-09, Aoba-ku, Sendai, Miyagi, 980-8579, Japan
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7
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Norton-Baker B, Denton MCR, Murphy NP, Fram B, Lim S, Erickson E, Gauthier NP, Beckham GT. Enabling high-throughput enzyme discovery and engineering with a low-cost, robot-assisted pipeline. Sci Rep 2024; 14:14449. [PMID: 38914665 PMCID: PMC11196671 DOI: 10.1038/s41598-024-64938-0] [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: 04/08/2024] [Accepted: 06/14/2024] [Indexed: 06/26/2024] Open
Abstract
As genomic databases expand and artificial intelligence tools advance, there is a growing demand for efficient characterization of large numbers of proteins. To this end, here we describe a generalizable pipeline for high-throughput protein purification using small-scale expression in E. coli and an affordable liquid-handling robot. This low-cost platform enables the purification of 96 proteins in parallel with minimal waste and is scalable for processing hundreds of proteins weekly per user. We demonstrate the performance of this method with the expression and purification of the leading poly(ethylene terephthalate) hydrolases reported in the literature. Replicate experiments demonstrated reproducibility and enzyme purity and yields (up to 400 µg) sufficient for comprehensive analyses of both thermostability and activity, generating a standardized benchmark dataset for comparing these plastic-degrading enzymes. The cost-effectiveness and ease of implementation of this platform render it broadly applicable to diverse protein characterization challenges in the biological sciences.
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Grants
- DE-SC0022024 U.S. Department of Energy, Office of Science, Office of Biological and Environmental Research (BER), Genomic Science Program
- DE-SC0022024 U.S. Department of Energy, Office of Science, Office of Biological and Environmental Research (BER), Genomic Science Program
- DE-SC0022024 U.S. Department of Energy, Office of Science, Office of Biological and Environmental Research (BER), Genomic Science Program
- DE-SC0022024 U.S. Department of Energy, Office of Science, Office of Biological and Environmental Research (BER), Genomic Science Program
- DE-SC0022024 U.S. Department of Energy, Office of Science, Office of Biological and Environmental Research (BER), Genomic Science Program
- DE-AC36-08GO28308 Advanced Materials and Manufacturing Technologies Office (AMMTO)
- DE-AC36-08GO28308 Advanced Materials and Manufacturing Technologies Office (AMMTO)
- DE-AC36-08GO28308 Advanced Materials and Manufacturing Technologies Office (AMMTO)
- DE-AC36-08GO28308 Advanced Materials and Manufacturing Technologies Office (AMMTO)
- U.S. Department of Energy Office of Energy Efficiency and Renewable Energy Bioenergy Technologies Office (BETO)
- Bio-Optimized Technologies to keep Thermoplastics out of Landfills and the Environment (BOTTLE) Consortium
- Dana-Farber Cancer Institute
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Affiliation(s)
- Brenna Norton-Baker
- Renewable Resources and Enabling Sciences Center, National Renewable Energy Laboratory, Golden, CO, USA
- BOTTLE Consortium, Golden, CO, USA
- Agile BioFoundry, Emeryville, CA, USA
| | - Mackenzie C R Denton
- Renewable Resources and Enabling Sciences Center, National Renewable Energy Laboratory, Golden, CO, USA
- BOTTLE Consortium, Golden, CO, USA
| | - Natasha P Murphy
- Renewable Resources and Enabling Sciences Center, National Renewable Energy Laboratory, Golden, CO, USA
- BOTTLE Consortium, Golden, CO, USA
| | - Benjamin Fram
- Department of Systems Biology, Harvard Medical School, Boston, MA, USA
| | - Samuel Lim
- Department of Systems Biology, Harvard Medical School, Boston, MA, USA
| | - Erika Erickson
- Renewable Resources and Enabling Sciences Center, National Renewable Energy Laboratory, Golden, CO, USA
- BOTTLE Consortium, Golden, CO, USA
| | - Nicholas P Gauthier
- Department of Systems Biology, Harvard Medical School, Boston, MA, USA.
- Department of Data Sciences, Dana-Farber Cancer Institute, Boston, MA, USA.
| | - Gregg T Beckham
- Renewable Resources and Enabling Sciences Center, National Renewable Energy Laboratory, Golden, CO, USA.
- BOTTLE Consortium, Golden, CO, USA.
- Agile BioFoundry, Emeryville, CA, USA.
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8
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Enache AC, Grecu I, Samoila P. Polyethylene Terephthalate (PET) Recycled by Catalytic Glycolysis: A Bridge toward Circular Economy Principles. MATERIALS (BASEL, SWITZERLAND) 2024; 17:2991. [PMID: 38930360 PMCID: PMC11205646 DOI: 10.3390/ma17122991] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/20/2024] [Revised: 06/13/2024] [Accepted: 06/14/2024] [Indexed: 06/28/2024]
Abstract
Plastic pollution has escalated into a critical global issue, with production soaring from 2 million metric tons in 1950 to 400.3 million metric tons in 2022. The packaging industry alone accounts for nearly 44% of this production, predominantly utilizing polyethylene terephthalate (PET). Alarmingly, over 90% of the approximately 1 million PET bottles sold every minute end up in landfills or oceans, where they can persist for centuries. This highlights the urgent need for sustainable management and recycling solutions to mitigate the environmental impact of PET waste. To better understand PET's behavior and promote its management within a circular economy, we examined its chemical and physical properties, current strategies in the circular economy, and the most effective recycling methods available today. Advancing PET management within a circular economy framework by closing industrial loops has demonstrated benefits such as reduced landfill waste, minimized energy consumption, and conserved raw resources. To this end, we identified and examined various strategies based on R-imperatives (ranging from 3R to 10R), focusing on the latest approaches aimed at significantly reducing PET waste by 2040. Additionally, a comparison of PET recycling methods (including primary, secondary, tertiary, and quaternary recycling, along with the concepts of "zero-order" and biological recycling techniques) was envisaged. Particular attention was paid to the heterogeneous catalytic glycolysis, which stands out for its rapid reaction time (20-60 min), high monomer yields (>90%), ease of catalyst recovery and reuse, lower costs, and enhanced durability. Accordingly, the use of highly efficient oxide-based catalysts for PET glycolytic degradation is underscored as a promising solution for large-scale industrial applications.
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Affiliation(s)
| | | | - Petrisor Samoila
- “Petru Poni” Institute of Macromolecular Chemistry, 41A Grigore Ghica Voda Alley, 700487 Iasi, Romania; (A.-C.E.); (I.G.)
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9
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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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10
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Naidu G, Nagar N, Poluri KM. Mechanistic Insights into Cellular and Molecular Basis of Protein-Nanoplastic Interactions. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2024; 20:e2305094. [PMID: 37786309 DOI: 10.1002/smll.202305094] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/16/2023] [Revised: 09/07/2023] [Indexed: 10/04/2023]
Abstract
Plastic waste is ubiquitously present across the world, and its nano/sub-micron analogues (plastic nanoparticles, PNPs), raise severe environmental concerns affecting organisms' health. Considering the direct and indirect toxic implications of PNPs, their biological impacts are actively being studied; lately, with special emphasis on cellular and molecular mechanistic intricacies. Combinatorial OMICS studies identified proteins as major regulators of PNP mediated cellular toxicity via activation of oxidative enzymes and generation of ROS. Alteration of protein function by PNPs results in DNA damage, organellar dysfunction, and autophagy, thus resulting in inflammation/cell death. The molecular mechanistic basis of these cellular toxic endeavors is fine-tuned at the level of structural alterations in proteins of physiological relevance. Detailed biophysical studies on such protein-PNP interactions evidenced prominent modifications in their structural architecture and conformational energy landscape. Another essential aspect of the protein-PNP interactions includes bioenzymatic plastic degradation perspective, as the interactive units of plastics are essentially nano-sized. Combining all these attributes of protein-PNP interactions, the current review comprehensively documented the contemporary understanding of the concerned interactions in the light of cellular, molecular, kinetic/thermodynamic details. Additionally, the applicatory, economical facet of these interactions, PNP biogeochemical cycle and enzymatic advances pertaining to plastic degradation has also been discussed.
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Affiliation(s)
- Goutami Naidu
- Department of Biosciences and Bioengineering, Indian Institute of Technology Roorkee, Roorkee, Uttarakhand, 247667, India
| | - Nupur Nagar
- Department of Biosciences and Bioengineering, Indian Institute of Technology Roorkee, Roorkee, Uttarakhand, 247667, India
| | - Krishna Mohan Poluri
- Department of Biosciences and Bioengineering, Indian Institute of Technology Roorkee, Roorkee, Uttarakhand, 247667, India
- Centre for Nanotechnology, Indian Institute of Technology Roorkee, Roorkee, Uttarakhand, 247667, India
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11
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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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12
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Qiu J, Chen Y, Zhang L, Wu J, Zeng X, Shi X, Liu L, Chen J. A comprehensive review on enzymatic biodegradation of polyethylene terephthalate. ENVIRONMENTAL RESEARCH 2024; 240:117427. [PMID: 37865324 DOI: 10.1016/j.envres.2023.117427] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/28/2023] [Revised: 10/11/2023] [Accepted: 10/15/2023] [Indexed: 10/23/2023]
Abstract
Polyethylene terephthalate (PET) is a polymer synthesized via the dehydration and condensation reaction between ethylene glycol and terephthalic acid. PET has emerged as one of the most extensively employed plastic materials due to its exceptional plasticity and durability. Nevertheless, PET has a complex structure and is extremely difficult to degrade in nature, causing severe pollution to the global ecological environment and posing a threat to human health. Currently, the methods for PET processing mainly include physical, chemical, and biological methods. Biological enzyme degradation is considered the most promising PET degradation method. In recent years, an increasing number of enzymes that can degrade PET have been identified, and they primarily target the ester bond of PET. This review comprehensively introduced the latest research progress in PET enzymatic degradation from the aspects of PET-degrading enzymes, PET biodegradation pathways, the catalytic mechanism of PET-degrading enzymes, and biotechnological strategies for enhancing PET-degrading enzymes. On this basis, the current challenges within the enzymatic PET degradation process were summarized, and the directions that need to be worked on in the future were pointed out. This review provides a reference and basis for the subsequent effective research on PET biodegradation.
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Affiliation(s)
- Jiarong Qiu
- School of Advanced Manufacturing, Fuzhou University, Jinjiang 362251, China; Development Center of Science and Education Park of Fuzhou University, Jinjiang, 362251, China
| | - Yuxin Chen
- School of Advanced Manufacturing, Fuzhou University, Jinjiang 362251, China
| | - Liangqing Zhang
- School of Advanced Manufacturing, Fuzhou University, Jinjiang 362251, China; Development Center of Science and Education Park of Fuzhou University, Jinjiang, 362251, China.
| | - Jinzhi Wu
- School of Advanced Manufacturing, Fuzhou University, Jinjiang 362251, China
| | - Xianhai Zeng
- College of Energy, Xiamen University, Xiamen 361102, China
| | - Xinguo Shi
- School of Advanced Manufacturing, Fuzhou University, Jinjiang 362251, China
| | - Lemian Liu
- School of Advanced Manufacturing, Fuzhou University, Jinjiang 362251, China
| | - Jianfeng Chen
- School of Advanced Manufacturing, Fuzhou University, Jinjiang 362251, China
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13
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Thomsen TB, Almdal K, Meyer AS. Significance of poly(ethylene terephthalate) (PET) substrate crystallinity on enzymatic degradation. N Biotechnol 2023; 78:162-172. [PMID: 37939899 DOI: 10.1016/j.nbt.2023.11.001] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2023] [Revised: 10/20/2023] [Accepted: 11/04/2023] [Indexed: 11/10/2023]
Abstract
Poly(ethylene terephthalate) (PET) is a semi-crystalline plastic polyester material with a global production volume of 83 Mt/year. PET is mainly used in textiles, but also widely used for packaging materials, notably plastic bottles, and is a major contributor to environmental plastic waste accumulation. Now that enzymes have been demonstrated to catalyze PET degradation, new options for sustainable bio-recycling of PET materials via enzymatic catalysis have emerged. The enzymatic degradation rate is strongly influenced by the properties of PET, notably the degree of crystallinity, XC. The higher the XC of the PET material, the slower the enzymatic rate. Crystallization of PET, resulting in increased XC, is induced thermally (via heating) and/or mechanically (via stretching), and the XC of most PET plastic bottles and microplastics exceeds what currently known enzymes can readily degrade. The enzymatic action occurs at the surface of the insoluble PET material and improves when the polyester chain mobility increases. The chain mobility increases drastically when the temperature exceeds the glass transition temperature, Tg, which is ∼40 °C at the surface layer of PET. Since PET crystallization starts at 70 °C, the ideal temperature for enzymatic degradation is just below 70 °C to balance high chain mobility and enzymatic reaction activation without inducing crystal formation. This paper reviews the current understanding on the properties of PET as an enzyme substrate and summarizes the most recent knowledge of how the crystalline and amorphous regions of PET form, and how the XC and the Tg impact the efficiency of enzymatic PET degradation.
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Affiliation(s)
- Thore Bach Thomsen
- Department of Biotechnology and Biomedicine, DTU Bioengineering, Protein Chemistry and Enzyme Technology Section, Building 221, Technical University of Denmark, 2800 Kgs Lyngby, Denmark
| | - Kristoffer Almdal
- DTU Chemistry, Building 206, Technical University of Denmark, 2800 Kgs Lyngby, Denmark
| | - Anne S Meyer
- Department of Biotechnology and Biomedicine, DTU Bioengineering, Protein Chemistry and Enzyme Technology Section, Building 221, Technical University of Denmark, 2800 Kgs Lyngby, Denmark.
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14
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Cribari MA, Unger MJ, Unarta IC, Ogorek AN, Huang X, Martell JD. Ultrahigh-Throughput Directed Evolution of Polymer-Degrading Enzymes Using Yeast Display. J Am Chem Soc 2023; 145:27380-27389. [PMID: 38051911 PMCID: PMC11058326 DOI: 10.1021/jacs.3c08291] [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] [Indexed: 12/07/2023]
Abstract
Enzymes that degrade synthetic polymers have attracted intense interest for eco-friendly plastic recycling. However, because enzymes did not evolve for the cleavage of abiotic polymers, directed evolution strategies are needed to enhance activity for plastic degradation. Previous directed evolution efforts relied on polymer degradation assays that were limited to screening ∼104 mutants. Here, we report a high-throughput yeast surface display platform to rapidly evaluate >107 enzyme mutants for increased activity in cleaving synthetic polymers. In this platform, individual yeast cells display distinct mutants, and enzyme activity is detected by a change in fluorescence upon the cleavage of a synthetic probe resembling a polymer of interest. Highly active mutants are isolated by fluorescence activated cell sorting and identified through DNA sequencing. To demonstrate this platform, we performed directed evolution of a polyethylene terephthalate (PET)-depolymerizing enzyme, leaf and branch compost cutinase (LCC). We identified activity-boosting mutations that substantially increased the kinetics of degradation of solid PET films. Biochemical assays and molecular dynamics (MD) simulations of the most active variants suggest that the H218Y mutation improves the binding of the enzyme to PET. Overall, this evolution platform increases the screening throughput of polymer-degrading enzymes by 3 orders of magnitude and identifies mutations that enhance kinetics for depolymerizing solid substrates.
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Affiliation(s)
- Mario A. Cribari
- Department of Chemistry, University of Wisconsin−Madison, Madison, Wisconsin 53706, United States
| | - Maxwell J. Unger
- Department of Chemistry, University of Wisconsin−Madison, Madison, Wisconsin 53706, United States
| | - Ilona C. Unarta
- Department of Chemistry, University of Wisconsin−Madison, Madison, Wisconsin 53706, United States
- Theoretical Chemistry Institute, Department of Chemistry, University of Wisconsin−Madison, Madison, Wisconsin 53706, United States
| | - Ashley N. Ogorek
- Department of Chemistry, University of Wisconsin−Madison, Madison, Wisconsin 53706, United States
| | - Xuhui Huang
- Department of Chemistry, University of Wisconsin−Madison, Madison, Wisconsin 53706, United States
- Theoretical Chemistry Institute, Department of Chemistry, University of Wisconsin−Madison, Madison, Wisconsin 53706, United States
| | - Jeffrey D. Martell
- Department of Chemistry, University of Wisconsin−Madison, Madison, Wisconsin 53706, United States
- Carbone Cancer Center, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin 53705, United States
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15
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Sui B, Wang T, Fang J, Hou Z, Shu T, Lu Z, Liu F, Zhu Y. Recent advances in the biodegradation of polyethylene terephthalate with cutinase-like enzymes. Front Microbiol 2023; 14:1265139. [PMID: 37849919 PMCID: PMC10577388 DOI: 10.3389/fmicb.2023.1265139] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2023] [Accepted: 09/15/2023] [Indexed: 10/19/2023] Open
Abstract
Polyethylene terephthalate (PET) is a synthetic polymer in the polyester family. It is widely found in objects used daily, including packaging materials (such as bottles and containers), textiles (such as fibers), and even in the automotive and electronics industries. PET is known for its excellent mechanical properties, chemical resistance, and transparency. However, these features (e.g., high hydrophobicity and high molecular weight) also make PET highly resistant to degradation by wild-type microorganisms or physicochemical methods in nature, contributing to the accumulation of plastic waste in the environment. Therefore, accelerated PET recycling is becoming increasingly urgent to address the global environmental problem caused by plastic wastes and prevent plastic pollution. In addition to traditional physical cycling (e.g., pyrolysis, gasification) and chemical cycling (e.g., chemical depolymerization), biodegradation can be used, which involves breaking down organic materials into simpler compounds by microorganisms or PET-degrading enzymes. Lipases and cutinases are the two classes of enzymes that have been studied extensively for this purpose. Biodegradation of PET is an attractive approach for managing PET waste, as it can help reduce environmental pollution and promote a circular economy. During the past few years, great advances have been accomplished in PET biodegradation. In this review, current knowledge on cutinase-like PET hydrolases (such as TfCut2, Cut190, HiC, and LCC) was described in detail, including the structures, ligand-protein interactions, and rational protein engineering for improved PET-degrading performance. In particular, applications of the engineered catalysts were highlighted, such as improving the PET hydrolytic activity by constructing fusion proteins. The review is expected to provide novel insights for the biodegradation of complex polymers.
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Affiliation(s)
- Beibei Sui
- School of Biological Science, Jining Medical University, Jining, Shandong, China
| | - Tao Wang
- School of Biological Science, Jining Medical University, Jining, Shandong, China
| | - Jingxiang Fang
- Rizhao Administration for Market Regulation, Rizhao, Shandong, China
| | - Zuoxuan Hou
- School of Biological Science, Jining Medical University, Jining, Shandong, China
| | - Ting Shu
- School of Biological Science, Jining Medical University, Jining, Shandong, China
| | - Zhenhua Lu
- College of Chemical and Biological Engineering, Zhejiang University, Hangzhou, Zhejiang, China
| | - Fei Liu
- School of Biological Science, Jining Medical University, Jining, Shandong, China
| | - Youshuang Zhu
- School of Biological Science, Jining Medical University, Jining, Shandong, China
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16
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Liu T, Gao H, Ren X, Xu G, Liu B, Wu N, Luo H, Wang Y, Tu T, Yao B, Guan F, Teng Y, Huang H, Tian J. Protein-protein interaction and site prediction using transfer learning. Brief Bioinform 2023; 24:bbad376. [PMID: 37870286 DOI: 10.1093/bib/bbad376] [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: 07/26/2023] [Revised: 09/14/2023] [Accepted: 10/02/2023] [Indexed: 10/24/2023] Open
Abstract
The advanced language models have enabled us to recognize protein-protein interactions (PPIs) and interaction sites using protein sequences or structures. Here, we trained the MindSpore ProteinBERT (MP-BERT) model, a Bidirectional Encoder Representation from Transformers, using protein pairs as inputs, making it suitable for identifying PPIs and their respective interaction sites. The pretrained model (MP-BERT) was fine-tuned as MPB-PPI (MP-BERT on PPI) and demonstrated its superiority over the state-of-the-art models on diverse benchmark datasets for predicting PPIs. Moreover, the model's capability to recognize PPIs among various organisms was evaluated on multiple organisms. An amalgamated organism model was designed, exhibiting a high level of generalization across the majority of organisms and attaining an accuracy of 92.65%. The model was also customized to predict interaction site propensity by fine-tuning it with PPI site data as MPB-PPISP. Our method facilitates the prediction of both PPIs and their interaction sites, thereby illustrating the potency of transfer learning in dealing with the protein pair task.
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Affiliation(s)
- Tuoyu Liu
- Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, Beijing 100081, China
| | - Han Gao
- Institute of Animal Science, Chinese Academy of Agricultural Sciences, Beijing 100193, China
| | - Xiaopu Ren
- Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, Beijing 100081, China
| | - Guoshun Xu
- Institute of Animal Science, Chinese Academy of Agricultural Sciences, Beijing 100193, China
| | - Bo Liu
- Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, Beijing 100081, China
| | - Ningfeng Wu
- Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, Beijing 100081, China
| | - Huiying Luo
- Institute of Animal Science, Chinese Academy of Agricultural Sciences, Beijing 100193, China
| | - Yuan Wang
- Institute of Animal Science, Chinese Academy of Agricultural Sciences, Beijing 100193, China
| | - Tao Tu
- Institute of Animal Science, Chinese Academy of Agricultural Sciences, Beijing 100193, China
| | - Bin Yao
- Institute of Animal Science, Chinese Academy of Agricultural Sciences, Beijing 100193, China
| | - Feifei Guan
- Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, Beijing 100081, China
| | - Yue Teng
- State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Academy of Military Medical Sciences, Beijing 100071, China
| | - Huoqing Huang
- Institute of Animal Science, Chinese Academy of Agricultural Sciences, Beijing 100193, China
| | - Jian Tian
- Institute of Animal Science, Chinese Academy of Agricultural Sciences, Beijing 100193, China
- Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, Beijing 100081, China
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17
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Makryniotis K, Nikolaivits E, Gkountela C, Vouyiouka S, Topakas E. Discovery of a polyesterase from Deinococcus maricopensis and comparison to the benchmark LCC ICCG suggests high potential for semi-crystalline post-consumer PET degradation. JOURNAL OF HAZARDOUS MATERIALS 2023; 455:131574. [PMID: 37150100 DOI: 10.1016/j.jhazmat.2023.131574] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/11/2023] [Revised: 05/02/2023] [Accepted: 05/02/2023] [Indexed: 05/09/2023]
Abstract
Plastic pollution remains a significant environmental challenge, with conventional waste management strategies proving insufficient in addressing the problem. Enzymatic degradation has emerged as a promising alternative, with LCCICCG, an engineered metagenome-derived cutinase, being the most effective in degrading polyethylene terephthalate (PET), the most commonly produced and discarded polyester. However, more efficient PET-hydrolases are needed for the upscaling of a PET-waste biorefinery. In this regard, the study reports the characterization of a novel, phylogenetically distinct, thermophilic polyesterase from Deinococcus maricopensis (DmPETase) and its comparison to LCCICCG. DmPETase is capable of degrading various synthetic polymers, including PET, polyurethane, as well as four semi-crystalline aliphatic polyesters. DmPETase was found to be comparable to LCCICCG at 50 °C in degrading semi-crystalline sections of post-consumer PET bottles, but it appeared to be less sensitive to crystallinity degree increase. This property makes DmPETase a new template for protein engineering endeavors to create an efficient biocatalyst to be integrated into the bio-recycling process of PET waste, without the need for amorphization of the materials.
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Affiliation(s)
- Konstantinos Makryniotis
- Industrial Biotechnology & Biocatalysis Group, Biotechnology Laboratory, School of Chemical Engineering, National Technical University of Athens, Athens, Greece
| | - Efstratios Nikolaivits
- Industrial Biotechnology & Biocatalysis Group, Biotechnology Laboratory, School of Chemical Engineering, National Technical University of Athens, Athens, Greece.
| | - Christina Gkountela
- Laboratory of Polymer Technology, School of Chemical Engineering, National Technical University of Athens, Athens, Greece
| | - Stamatina Vouyiouka
- Laboratory of Polymer Technology, School of Chemical Engineering, National Technical University of Athens, Athens, Greece
| | - Evangelos Topakas
- Industrial Biotechnology & Biocatalysis Group, Biotechnology Laboratory, School of Chemical Engineering, National Technical University of Athens, Athens, Greece.
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