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Lerner A, Benzvi C, Vojdani A. The Frequently Used Industrial Food Process Additive, Microbial Transglutaminase: Boon or Bane. Nutr Rev 2024:nuae087. [PMID: 38960726 DOI: 10.1093/nutrit/nuae087] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/05/2024] Open
Abstract
Microbial transglutaminase (mTG) is a frequently consumed processed food additive, and use of its cross-linked complexes is expanding rapidly. It was designated as a processing aid and was granted the generally recognized as safe (GRAS) classification decades ago, thus avoiding thorough assessment according to current criteria of toxicity and public health safety. In contrast to the manufacturer's declarations and claims, mTG and/or its transamidated complexes are proinflammatory, immunogenic, allergenic, pathogenic, and potentially toxic, hence raising concerns for public health. Being a member of the transglutaminase family and functionally imitating the tissue transglutaminase, mTG was recently identified as a potential inducer of celiac disease. Microbial transglutaminase and its docked complexes have numerous detrimental effects. Those harmful aspects are denied by the manufacturers, who claim the enzyme is deactivated when heated or by gastric acidity, and that its covalently linked isopeptide bonds are safe. The present narrative review describes the potential side effects of mTG, highlighting its thermostability and activity over a broad pH range, thus, challenging the manufacturers' and distributers' safety claims. The national food regulatory authorities and the scientific community are urged to reevaluate mTG's GRAS status, prioritizing public health protection against the possible risks associated with this enzyme and its health-damaging consequences.
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Affiliation(s)
- Aaron Lerner
- Research Department, Chaim Sheba Medical Center, The Zabludowicz Research Center for Autoimmune Diseases, 52621 Tel Hashomer, Israel
| | - Carina Benzvi
- Research Department, Chaim Sheba Medical Center, The Zabludowicz Research Center for Autoimmune Diseases, 52621 Tel Hashomer, Israel
| | - Aristo Vojdani
- Research Department, Immunosciences Lab., Inc., Los Angeles, CA 90035, USA
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Masiá C, Ong L, Logan A, Stockmann R, Gambetta J, Jensen PE, Rahimi Yazdi S, Gras S. Enhancing the textural and rheological properties of fermentation-induced pea protein emulsion gels with transglutaminase. SOFT MATTER 2023; 20:133-143. [PMID: 38054382 DOI: 10.1039/d3sm01001e] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/07/2023]
Abstract
The aim of this study was to assess how transglutaminase (TG) impacts the microstructure, texture, and rheological properties of fermentation-induced pea protein emulsion gels. Additionally, the study examined the influence of storage time on the functional properties of these gels. Fermentation-induced pea protein gels were produced in the presence or absence of TG and stored for 1, 4, 8, 12, and 16 weeks. Texture analysis, rheological measurements, moisture content and microstructure evaluation with confocal laser scanning microscopy (CLSM) and 3D image analysis were conducted to explore the effects of TG on the structural and rheological properties of the fermented samples. The porosity of the protein networks in the pea gels decreased in the presence of TG, the storage modulus increased and the textural characteristics were significantly improved, resulting in harder and more springy gels. The gel porosity increased in gels with and without TG after storage but the effect of storage on textural and rheological properties was limited, indicating limited structural rearrangement once the fermentation-induced pea protein emulsion gels are formed. Greater coalescence was observed for oil droplets within the gel matrix after 16 weeks of storage in the absence of TG, consistent with these protein structures being weaker than the more structurally stable TG-treated gels. This study shows that TG treatment is a powerful tool to enhance the textural and rheological properties of fermentation-induced pea protein emulsion gels.
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Affiliation(s)
- Carmen Masiá
- Department of Food Science, University of Copenhagen, Rolighedsvej 26, 1958 Frederiksberg, Denmark.
- Plant Based Application Department, Chr. Hansen A/S, Bøge Alle 10-12, 2970 Hørsholm, Denmark
- The Bio21 Molecular Science and Biotechnology Institute, The University of Melbourne, Parkville, VIC 3010, Australia
- CSIRO Agriculture and Food, 671 Sneydes Road, Werribee, Victoria 3030, Australia
| | - Lydia Ong
- The Bio21 Molecular Science and Biotechnology Institute, The University of Melbourne, Parkville, VIC 3010, Australia
| | - Amy Logan
- CSIRO Agriculture and Food, 671 Sneydes Road, Werribee, Victoria 3030, Australia
| | - Regine Stockmann
- CSIRO Agriculture and Food, 671 Sneydes Road, Werribee, Victoria 3030, Australia
| | - Joanna Gambetta
- CSIRO Agriculture and Food, 671 Sneydes Road, Werribee, Victoria 3030, Australia
| | - Poul Erik Jensen
- Department of Food Science, University of Copenhagen, Rolighedsvej 26, 1958 Frederiksberg, Denmark.
| | - Saeed Rahimi Yazdi
- Plant Based Application Department, Chr. Hansen A/S, Bøge Alle 10-12, 2970 Hørsholm, Denmark
| | - Sally Gras
- The Bio21 Molecular Science and Biotechnology Institute, The University of Melbourne, Parkville, VIC 3010, Australia
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Liu Y, Jia K, Chen H, Wang Z, Zhao W, Zhu L. Cold-adapted enzymes: mechanisms, engineering and biotechnological application. Bioprocess Biosyst Eng 2023; 46:1399-1410. [PMID: 37486422 DOI: 10.1007/s00449-023-02904-2] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2023] [Accepted: 07/05/2023] [Indexed: 07/25/2023]
Abstract
Most cold-adapted enzymes display high catalytic activity at low temperatures (20-25 °C) and can still maintain more than 40-50% of their maximum activity at lower temperatures (0-10 °C) but are inactivated after a moderate increase in temperature. The activity of some cold-adapted enzymes increases significantly in the presence of high salt concentrations and metal ions. Interestingly, we also observed that some cold-adapted enzymes have a wide range of optimum temperatures, exhibiting not only maximum activity under low-temperature conditions but also the ability to maintain high enzyme activity under high-temperature conditions, which is a novel feature of cold-adapted enzymes. This unique property of cold-adapted enzymes is generally attractive for biotechnological and industrial applications because these enzymes can reduce energy consumption and the chance of microbial contamination, thereby lowering the production costs and maintaining the flavor, taste and quality of foods. How high catalytic activity is maintained at low temperatures remains unknown. The relationship between the structure of cold-adapted enzymes and their activity, flexibility and stability is complex, and thus far, a unified explanation has not been provided. Herein, we systematically review the sources, catalytic characteristics and cold adaptation of enzymes from four enzymes categories systematically and discuss how these properties may be exploited in biotechnology. A thorough understanding of the properties, catalytic mechanisms, and engineering of cold-adapted enzymes is critical for future biotechnological applications in the detergent industry and food and beverage industries.
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Affiliation(s)
- Yan Liu
- Cooperative Innovation Center of Industrial Fermentation (Ministry of Education and Hubei Province), Key Laboratory of Fermentation Engineering (Ministry of Education), Hubei Key Laboratory of Industrial Microbiology, National "111" Center for Cellular Regulation and Molecular Pharmaceutics, Hubei University of Technology, Wuhan, 430068, China
| | - Kaizhi Jia
- Cooperative Innovation Center of Industrial Fermentation (Ministry of Education and Hubei Province), Key Laboratory of Fermentation Engineering (Ministry of Education), Hubei Key Laboratory of Industrial Microbiology, National "111" Center for Cellular Regulation and Molecular Pharmaceutics, Hubei University of Technology, Wuhan, 430068, China
| | - Hongyang Chen
- Cooperative Innovation Center of Industrial Fermentation (Ministry of Education and Hubei Province), Key Laboratory of Fermentation Engineering (Ministry of Education), Hubei Key Laboratory of Industrial Microbiology, National "111" Center for Cellular Regulation and Molecular Pharmaceutics, Hubei University of Technology, Wuhan, 430068, China
| | - Zhulin Wang
- Cooperative Innovation Center of Industrial Fermentation (Ministry of Education and Hubei Province), Key Laboratory of Fermentation Engineering (Ministry of Education), Hubei Key Laboratory of Industrial Microbiology, National "111" Center for Cellular Regulation and Molecular Pharmaceutics, Hubei University of Technology, Wuhan, 430068, China
| | - Wei Zhao
- State Key Laboratory of Microbial Technology, Shandong University, Qingdao, 266237, China
| | - Liwen Zhu
- Cooperative Innovation Center of Industrial Fermentation (Ministry of Education and Hubei Province), Key Laboratory of Fermentation Engineering (Ministry of Education), Hubei Key Laboratory of Industrial Microbiology, National "111" Center for Cellular Regulation and Molecular Pharmaceutics, Hubei University of Technology, Wuhan, 430068, China.
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Kolotylo V, Piwowarek K, Kieliszek M. Microbiological transglutaminase: Biotechnological application in the food industry. Open Life Sci 2023; 18:20220737. [PMID: 37791057 PMCID: PMC10543708 DOI: 10.1515/biol-2022-0737] [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: 07/12/2023] [Revised: 08/31/2023] [Accepted: 09/03/2023] [Indexed: 10/05/2023] Open
Abstract
Microbial transglutaminases (mTGs) belong to the family of global TGs, isolated and characterised by various bacterial strains, with the first being Streptomyces mobaraensis. This literature review also discusses TGs of animal and plant origin. TGs catalyse the formation of an isopeptide bond, cross-linking the amino and acyl groups. Due to its broad enzymatic activity, TG is extensively utilised in the food industry. The annual net growth in the utilisation of enzymes in the food processing industry is estimated to be 21.9%. As of 2020, the global food enzymes market was valued at around $2.3 billion USD (mTG market was estimated to be around $200 million USD). Much of this growth is attributed to the applications of mTG, benefiting both producers and consumers. In the food industry, TG enhances gelation and modifies emulsification, foaming, viscosity, and water-holding capacity. Research on TG, mainly mTG, provides increasing insights into the wide range of applications of this enzyme in various industrial sectors and promotes enzymatic processing. This work presents the characteristics of TGs, their properties, and the rationale for their utilisation. The review aims to provide theoretical foundations that will assist researchers worldwide in building a methodological framework and furthering the advancement of biotechnology research.
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Affiliation(s)
- Vitaliy Kolotylo
- Department of Food Biotechnology and Microbiology, Institute of Food Sciences, Warsaw University of Life Sciences – SGGW, Nowoursynowska 159 C, 02-776Warsaw, Poland
| | - Kamil Piwowarek
- Department of Food Biotechnology and Microbiology, Institute of Food Sciences, Warsaw University of Life Sciences – SGGW, Nowoursynowska 159 C, 02-776Warsaw, Poland
| | - Marek Kieliszek
- Department of Food Biotechnology and Microbiology, Institute of Food Sciences, Warsaw University of Life Sciences – SGGW, Nowoursynowska 159 C, 02-776Warsaw, Poland
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Tian X, Zhao K, Teng A, Li Y, Wang W. A rethinking of collagen as tough biomaterials in meat packaging: assembly from native to synthetic. Crit Rev Food Sci Nutr 2022; 64:957-977. [PMID: 35997287 DOI: 10.1080/10408398.2022.2111401] [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] [Indexed: 11/03/2022]
Abstract
Due to the high moisture-associated typical rheology and the changeable and harsh processing conditions in the production process, packaging materials for meat products have higher requirements including a sufficient mechanical strength and proper ductility. Collagen, a highly conserved structural protein consisting of a triple helix of Gly-X-Y repeats, has been proved to be suitable packaging material for meat products. The treated animal digestive tract (i.e. the casing) is the perfect natural packaging material for wrapping meat into sausage. Its thin walls, strong toughness and impact resistance make it the oldest and best edible meat packaging. Collagen casing is another wisdom of meat packaging, which is made by collagen fibers from hide skin, presenting a rapid growth in casing market. To strengthen mechanical strength and barrier behaviors of collagen-based packaging materials, different physical, chemical, and biological cross-linking methods are springing up exuberantly, as well as a variety of reinforcement approaches including nanotechnology. In addition, the rapid development of biomimetic technology also provides a good research idea and means for the promotion of collagen's assembly and relevant mechanical properties. This review can offer some reference on fundamental theory and practical application of collagenous materials in meat products.
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Affiliation(s)
- Xiaojing Tian
- College of Food Science and Engineering, Tianjin University of Science & Technology, Tianjin, China
| | - KaiXuan Zhao
- College of Food Science and Engineering, Tianjin University of Science & Technology, Tianjin, China
| | - Anguo Teng
- College of Food Science and Engineering, Tianjin University of Science & Technology, Tianjin, China
| | - Yu Li
- College of Biotechnology, Tianjin University of Science & Technology, Tianjin, China
| | - Wenhang Wang
- College of Food Science and Engineering, Tianjin University of Science & Technology, Tianjin, China
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Cold-active enzymes in the dairy industry: Insight into cold adaption mechanisms and their applications. Trends Food Sci Technol 2022. [DOI: 10.1016/j.tifs.2022.05.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Koczoń P, Josefsson H, Michorowska S, Tarnowska K, Kowalska D, Bartyzel BJ, Niemiec T, Lipińska E, Gruczyńska-Sękowska E. The Influence of the Structure of Selected Polymers on Their Properties and Food-Related Applications. Polymers (Basel) 2022; 14:polym14101962. [PMID: 35631843 PMCID: PMC9146511 DOI: 10.3390/polym14101962] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2022] [Revised: 04/14/2022] [Accepted: 05/09/2022] [Indexed: 11/16/2022] Open
Abstract
Every application of a substance results from the macroscopic property of the substance that is related to the substance’s microscopic structure. For example, the forged park gate in your city was produced thanks to the malleability and ductility of metals, which are related to the ability of shifting of layers of metal cations, while fire extinguishing powders use the high boiling point of compounds related to their regular ionic and covalent structures. This also applies to polymers. The purpose of this review is to summarise and present information on selected food-related biopolymers, with special attention on their respective structures, related properties, and resultant applications. Moreover, this paper also highlights how the treatment method used affects the structure, properties, and, hence, applications of some polysaccharides. Despite a strong focus on food-related biopolymers, this review is addressed to a broad community of both material engineers and food researchers.
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Affiliation(s)
- Piotr Koczoń
- Department of Chemistry, Institute of Food Sciences, Warsaw University of Life Sciences, 02-776 Warsaw, Poland; (P.K.); (K.T.); (D.K.)
| | | | - Sylwia Michorowska
- Department of Bioanalysis and Drug Analysis, Faculty of Pharmacy, Medical University of Warsaw, 02-097 Warsaw, Poland;
| | - Katarzyna Tarnowska
- Department of Chemistry, Institute of Food Sciences, Warsaw University of Life Sciences, 02-776 Warsaw, Poland; (P.K.); (K.T.); (D.K.)
| | - Dorota Kowalska
- Department of Chemistry, Institute of Food Sciences, Warsaw University of Life Sciences, 02-776 Warsaw, Poland; (P.K.); (K.T.); (D.K.)
| | - Bartłomiej J. Bartyzel
- Department of Morphological Sciences, Institute of Veterinary Medicine, Warsaw University of Life Sciences, 02-776 Warsaw, Poland;
| | - Tomasz Niemiec
- Animals Nutrition Department, Institute of Animal Sciences, Warsaw University of Life Sciences, 02-786 Warsaw, Poland;
| | - Edyta Lipińska
- Department of Biotechnology, Microbiology and Food Evaluation, Institute of Food Sciences, Warsaw University of Life Sciences, 02-776 Warsaw, Poland;
| | - Eliza Gruczyńska-Sękowska
- Department of Chemistry, Institute of Food Sciences, Warsaw University of Life Sciences, 02-776 Warsaw, Poland; (P.K.); (K.T.); (D.K.)
- Correspondence:
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Zhang Y, Li C, Geary T, Jardim A, He S, Simpson BK. Cold setting of gelatin–antioxidant peptides composite hydrogels using a new psychrophilic recombinant transglutaminase (rTGase). Food Hydrocoll 2022. [DOI: 10.1016/j.foodhyd.2021.107116] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Lerner A, Benzvi C. Microbial Transglutaminase Is a Very Frequently Used Food Additive and Is a Potential Inducer of Autoimmune/Neurodegenerative Diseases. TOXICS 2021; 9:toxics9100233. [PMID: 34678929 PMCID: PMC8537092 DOI: 10.3390/toxics9100233] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/24/2021] [Revised: 09/14/2021] [Accepted: 09/22/2021] [Indexed: 12/12/2022]
Abstract
Microbial transglutaminase (mTG) is a heavily used food additive and its industrial transamidated complexes usage is rising rapidly. It was classified as a processing aid and was granted the GRAS (generally recognized as safe) definition, thus escaping full and thorough toxic and safety evaluations. Despite the manufacturers claims, mTG or its cross-linked compounds are immunogenic, pathogenic, proinflammatory, allergenic and toxic, and pose a risk to public health. The enzyme is a member of the transglutaminase family and imitates the posttranslational modification of gluten, by the tissue transglutaminase, which is the autoantigen of celiac disease. The deamidated and transamidated gliadin peptides lose their tolerance and induce the gluten enteropathy. Microbial transglutaminase and its complexes increase intestinal permeability, suppresses enteric protective pathways, enhances microbial growth and gliadin peptide’s epithelial uptake and can transcytose intra-enterocytically to face the sub-epithelial immune cells. The present review updates on the potentially detrimental side effects of mTG, aiming to interest the scientific community, induce food regulatory authorities’ debates on its safety, and protect the public from the mTG unwanted effects.
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Affiliation(s)
- Aaron Lerner
- Chaim Sheba Medical Center, The Zabludowicz Research Center for Autoimmune Diseases, Tel Hashomer 5262000, Israel;
- Ariel University, Ariel 40700, Israel
- Correspondence: ; Tel.: +972-525-919484
| | - Carina Benzvi
- Chaim Sheba Medical Center, The Zabludowicz Research Center for Autoimmune Diseases, Tel Hashomer 5262000, Israel;
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Lerner A, Ramesh A, Matthias T. The temperature and pH repertoire of the transglutaminase family is expanding. FEBS Open Bio 2021; 10:492-494. [PMID: 32170837 PMCID: PMC7137796 DOI: 10.1002/2211-5463.12839] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2020] [Accepted: 03/11/2020] [Indexed: 12/11/2022] Open
Abstract
Transglutaminases (TGs) play important roles in the food industry, pharmacology, and biotechnology, but as protein cross‐linkers, their complexes are stable, resistant, immunogenic, and potentially pathogenic. Many TGs have been characterized, but they operate in narrow temperature and pH range limits. In a research article in this issue, Clemens Furnes and colleagues describe a novel cold‐adapted TG from Atlantic cod, which expands the operating boundaries to a lower temperature and a wider pH. In this accompanying commentary, we discuss how this TG opens new applications in cold environments and can be deactivated by heating. New sources of TGs should be explored in hot environments like hot springs, in order to increase the temperature and widen the pH ranges for human and industrial benefits.
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Yusof NA, Hashim NHF, Bharudin I. Cold Adaptation Strategies and the Potential of Psychrophilic Enzymes from the Antarctic Yeast, Glaciozyma antarctica PI12. J Fungi (Basel) 2021; 7:jof7070528. [PMID: 34209103 PMCID: PMC8306469 DOI: 10.3390/jof7070528] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2021] [Revised: 06/19/2021] [Accepted: 06/25/2021] [Indexed: 12/20/2022] Open
Abstract
Psychrophilic organisms possess several adaptive strategies which allow them to sustain life at low temperatures between −20 to 20 °C. Studies on Antarctic psychrophiles are interesting due to the multiple stressors that exist on the permanently cold continent. These organisms produce, among other peculiarities, cold-active enzymes which not only have tremendous biotechnological potential but are valuable models for fundamental research into protein structure and function. Recent innovations in omics technologies such as genomics, transcriptomics, proteomics and metabolomics have contributed a remarkable perspective of the molecular basis underpinning the mechanisms of cold adaptation. This review critically discusses similar and different strategies of cold adaptation in the obligate psychrophilic yeast, Glaciozyma antarctica PI12 at the molecular (genome structure, proteins and enzymes, gene expression) and physiological (antifreeze proteins, membrane fluidity, stress-related proteins) levels. Our extensive studies on G. antarctica have revealed significant insights towards the innate capacity of- and the adaptation strategies employed by this psychrophilic yeast for life in the persistent cold. Furthermore, several cold-active enzymes and proteins with biotechnological potential are also discussed.
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Affiliation(s)
- Nur Athirah Yusof
- Biotechnology Research Institute, Universiti Malaysia Sabah, Jalan UMS, Kota Kinabalu 88400, Sabah, Malaysia;
| | - Noor Haza Fazlin Hashim
- Water Quality Laboratory, National Water Research Institute Malaysia (NAHRIM), Ministry of Environment and Water, Jalan Putra Permai, Seri Kembangan 43300, Selangor, Malaysia;
| | - Izwan Bharudin
- Department of Biological Sciences and Biotechnology, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, Bangi 43600, Selangor, Malaysia
- Correspondence:
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12
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Effect of introducing a disulfide bridge on the thermostability of microbial transglutaminase from Streptomyces mobaraensis. Appl Microbiol Biotechnol 2021; 105:2737-2745. [PMID: 33738551 DOI: 10.1007/s00253-021-11200-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2020] [Revised: 02/11/2021] [Accepted: 02/24/2021] [Indexed: 10/21/2022]
Abstract
Microbial transglutaminase (MTG) has been used extensively in academic research and the food industry through cross-linking or posttranslational modification of proteins. In our previous paper, the activity-increased MTG mutants were obtained by means of rational mutagenesis and random mutagenesis coupled with the newly developed screening system. In addition, the improvement of heat resistance of MTG is needed to expand further its industrial applications. Here, a structure-based rational enzyme engineering approach was applied to improve the thermostability of MTG by introducing an artificial disulfide bridge. As a result of narrowing down candidates using a rational approach, we successfully engineered a disulfide bridge into the N-terminal region of MTG by substituting Thr-7 and Glu-58 with cysteine. The T7C/E58C mutant was observed to have a de novo disulfide bridge and showed an increased melting temperature (Tm value) of 4.3 °C with retained enzymatic activity. To address the benefit-gained reason, we focused on the Cβ temperature factor of the amino-acid residues that might form a disulfide bridge in MTG. Introducing the disulfide bridge had no remarkable effect on the mutant aiming to stabilize the high temperature factor. On the other hand, the mutation was effective on the relatively stable region. The introduction of a disulfide bridge may therefore be effective to stabilize further the relatively stable part. This finding is considered to be useful for the rational design of mutants aiming at heat resistance of proteins.Key Points• Microbial transglutaminase (MTG) is used as a binder in the food industry.• MTG has the potential for use in the manufacturing of various commercial materials.• Enhanced thermostability was observed for the disulfide bridge mutant, T7C/G58C.
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Maddock RMA, Pollard GJ, Moreau NG, Perry JJ, Race PR. Enzyme-catalysed polymer cross-linking: Biocatalytic tools for chemical biology, materials science and beyond. Biopolymers 2020; 111:e23390. [PMID: 32640085 DOI: 10.1002/bip.23390] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2020] [Revised: 06/13/2020] [Accepted: 06/15/2020] [Indexed: 12/11/2022]
Abstract
Intermolecular cross-linking is one of the most important techniques that can be used to fundamentally alter the material properties of a polymer. The introduction of covalent bonds between individual polymer chains creates 3D macromolecular assemblies with enhanced mechanical properties and greater chemical or thermal tolerances. In contrast to many chemical cross-linking reactions, which are the basis of thermoset plastics, enzyme catalysed processes offer a complimentary paradigm for the assembly of cross-linked polymer networks through their predictability and high levels of control. Additionally, enzyme catalysed reactions offer an inherently 'greener' and more biocompatible approach to covalent bond formation, which could include the use of aqueous solvents, ambient temperatures, and heavy metal-free reagents. Here, we review recent progress in the development of biocatalytic methods for polymer cross-linking, with a specific focus on the most promising candidate enzyme classes and their underlying catalytic mechanisms. We also provide exemplars of the use of enzyme catalysed cross-linking reactions in industrially relevant applications, noting the limitations of these approaches and outlining strategies to mitigate reported deficiencies.
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Affiliation(s)
- Rosie M A Maddock
- School of Biochemistry, University of Bristol, University Walk, Bristol, UK.,BrisSynBio Synthetic Biology Research Centre, Life Sciences Building, Tyndall Avenue University of Bristol, Bristol, UK
| | - Gregory J Pollard
- School of Biochemistry, University of Bristol, University Walk, Bristol, UK
| | - Nicolette G Moreau
- School of Biochemistry, University of Bristol, University Walk, Bristol, UK
| | - Justin J Perry
- Department of Applied Sciences, Northumbria University, Ellison Building, Newcastle upon Tyne, UK
| | - Paul R Race
- School of Biochemistry, University of Bristol, University Walk, Bristol, UK.,BrisSynBio Synthetic Biology Research Centre, Life Sciences Building, Tyndall Avenue University of Bristol, Bristol, UK
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