1
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Mukhopadhyay A, Karu K, Dalby PA. Two-substrate enzyme engineering using small libraries that combine the substrate preferences from two different variant lineages. Sci Rep 2024; 14:1287. [PMID: 38218974 PMCID: PMC10787763 DOI: 10.1038/s41598-024-51831-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2023] [Accepted: 01/09/2024] [Indexed: 01/15/2024] Open
Abstract
Improving the range of substrates accepted by enzymes with high catalytic activity remains an important goal for the industrialisation of biocatalysis. Many enzymes catalyse two-substrate reactions which increases the complexity in engineering them for the synthesis of alternative products. Often mutations are found independently that can improve the acceptance of alternatives to each of the two substrates. Ideally, we would be able to combine mutations identified for each of the two alternative substrates, and so reprogramme new enzyme variants that synthesise specific products from their respective two-substrate combinations. However, as we have previously observed for E. coli transketolase, the mutations that improved activity towards aromatic acceptor aldehydes, did not successfully recombine with mutations that switched the donor substrate to pyruvate. This likely results from several active site residues having multiple roles that can affect both of the substrates, as well as structural interactions between the mutations themselves. Here, we have designed small libraries, including both natural and non-natural amino acids, based on the previous mutational sites that impact on acceptance of the two substrates, to achieve up to 630× increases in kcat for the reaction with 3-formylbenzoic acid (3-FBA) and pyruvate. Computational docking was able to determine how the mutations shaped the active site to improve the proximity of the 3-FBA substrate relative to the enamine-TPP intermediate, formed after the initial reaction with pyruvate. This work opens the way for small libraries to rapidly reprogramme enzyme active sites in a plug and play approach to catalyse new combinations of two-substrate reactions.
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Affiliation(s)
- Arka Mukhopadhyay
- Department of Biochemical Engineering, UCL, Bernard Katz Building, Gower Street, London, WC1E 6BT, UK
| | - Kersti Karu
- Department of Chemistry, UCL, 20 Gordon Street, London, WC1H 0AJ, UK
| | - Paul A Dalby
- Department of Biochemical Engineering, UCL, Bernard Katz Building, Gower Street, London, WC1E 6BT, UK.
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2
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Grandi E, Feyza Özgen F, Schmidt S, Poelarends GJ. Enzymatic Oxy- and Amino-Functionalization in Biocatalytic Cascade Synthesis: Recent Advances and Future Perspectives. Angew Chem Int Ed Engl 2023; 62:e202309012. [PMID: 37639631 DOI: 10.1002/anie.202309012] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2023] [Revised: 08/27/2023] [Accepted: 08/28/2023] [Indexed: 08/31/2023]
Abstract
Biocatalytic cascades are a powerful tool for building complex molecules containing oxygen and nitrogen functionalities. Moreover, the combination of multiple enzymes in one pot offers the possibility to minimize downstream processing and waste production. In this review, we illustrate various recent efforts in the development of multi-step syntheses involving C-O and C-N bond-forming enzymes to produce high value-added compounds, such as pharmaceuticals and polymer precursors. Both in vitro and in vivo examples are discussed, revealing the respective advantages and drawbacks. The use of engineered enzymes to boost the cascades outcome is also addressed and current co-substrate and cofactor recycling strategies are presented, highlighting the importance of atom economy. Finally, tools to overcome current challenges for multi-enzymatic oxy- and amino-functionalization reactions are discussed, including flow systems with immobilized biocatalysts and cascades in confined nanomaterials.
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Affiliation(s)
- Eleonora Grandi
- Department of Chemical and Pharmaceutical Biology, University of Groningen, Antonius Deusinglaan 1, 9713 AV, Groningen, The Netherlands
| | - Fatma Feyza Özgen
- Department of Chemical and Pharmaceutical Biology, University of Groningen, Antonius Deusinglaan 1, 9713 AV, Groningen, The Netherlands
| | - Sandy Schmidt
- Department of Chemical and Pharmaceutical Biology, University of Groningen, Antonius Deusinglaan 1, 9713 AV, Groningen, The Netherlands
| | - Gerrit J Poelarends
- Department of Chemical and Pharmaceutical Biology, University of Groningen, Antonius Deusinglaan 1, 9713 AV, Groningen, The Netherlands
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3
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Buller R, Lutz S, Kazlauskas RJ, Snajdrova R, Moore JC, Bornscheuer UT. From nature to industry: Harnessing enzymes for biocatalysis. Science 2023; 382:eadh8615. [PMID: 37995253 DOI: 10.1126/science.adh8615] [Citation(s) in RCA: 26] [Impact Index Per Article: 26.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2023] [Accepted: 10/17/2023] [Indexed: 11/25/2023]
Abstract
Biocatalysis harnesses enzymes to make valuable products. This green technology is used in countless applications from bench scale to industrial production and allows practitioners to access complex organic molecules, often with fewer synthetic steps and reduced waste. The last decade has seen an explosion in the development of experimental and computational tools to tailor enzymatic properties, equipping enzyme engineers with the ability to create biocatalysts that perform reactions not present in nature. By using (chemo)-enzymatic synthesis routes or orchestrating intricate enzyme cascades, scientists can synthesize elaborate targets ranging from DNA and complex pharmaceuticals to starch made in vitro from CO2-derived methanol. In addition, new chemistries have emerged through the combination of biocatalysis with transition metal catalysis, photocatalysis, and electrocatalysis. This review highlights recent key developments, identifies current limitations, and provides a future prospect for this rapidly developing technology.
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Affiliation(s)
- R Buller
- Competence Center for Biocatalysis, Institute of Chemistry and Biotechnology, Zurich University of Applied Sciences, 8820 Wädenswil, Switzerland
| | - S Lutz
- Codexis Incorporated, Redwood City, CA 94063, USA
| | - R J Kazlauskas
- Department of Biochemistry, Molecular Biology and Biophysics, Biotechnology Institute, University of Minnesota, Saint Paul, MN 55108, USA
| | - R Snajdrova
- Novartis Institutes for BioMedical Research, Global Discovery Chemistry, 4056 Basel, Switzerland
| | - J C Moore
- MRL, Merck & Co., Rahway, NJ 07065, USA
| | - U T Bornscheuer
- Institute of Biochemistry, Dept. of Biotechnology and Enzyme Catalysis, Greifswald University, Greifswald, Germany
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4
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Morris P, García-Arrazola R, Rios-Solis L, Dalby PA. Biophysical characterization of the inactivation of E. coli transketolase by aqueous co-solvents. Sci Rep 2021; 11:23584. [PMID: 34880340 PMCID: PMC8654844 DOI: 10.1038/s41598-021-03001-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2021] [Accepted: 11/24/2021] [Indexed: 11/09/2022] Open
Abstract
Transketolase (TK) has been previously engineered, using semi-rational directed evolution and substrate walking, to accept increasingly aliphatic, cyclic, and then aromatic substrates. This has ultimately led to the poor water solubility of new substrates, as a potential bottleneck to further exploitation of this enzyme in biocatalysis. Here we used a range of biophysical studies to characterise the response of both E. coli apo- and holo-TK activity and structure to a range of polar organic co-solvents: acetonitrile (AcCN), n-butanol (nBuOH), ethyl acetate (EtOAc), isopropanol (iPrOH), and tetrahydrofuran (THF). The mechanism of enzyme deactivation was found to be predominantly via solvent-induced local unfolding. Holo-TK is thermodynamically more stable than apo-TK and yet for four of the five co-solvents it retained less activity than apo-TK after exposure to organic solvents, indicating that solvent tolerance was not simply correlated to global conformational stability. The co-solvent concentrations required for complete enzyme inactivation was inversely proportional to co-solvent log(P), while the unfolding rate was directly proportional, indicating that the solvents interact with and partially unfold the enzyme through hydrophobic contacts. Small amounts of aggregate formed in some cases, but this was not sufficient to explain the enzyme inactivation. TK was found to be tolerant to 15% (v/v) iPrOH, 10% (v/v) AcCN, or 6% (v/v) nBuOH over 3 h. This work indicates that future attempts to engineer the enzyme to better tolerate co-solvents should focus on increasing the stability of the protein to local unfolding, particularly in and around the cofactor-binding loops.
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Affiliation(s)
- Phattaraporn Morris
- Department of Biochemical Engineering, University College London, Bernard Katz Building, Gower Street, London, WC1E 6BT, UK
- Chemical Metrology and Biometry Department, National Institute of Metrology, 3/4-5 Moo 3, Klong 5, Klong Luang, 12120, Pathumthani, Thailand
| | - Ribia García-Arrazola
- Department of Biochemical Engineering, University College London, Bernard Katz Building, Gower Street, London, WC1E 6BT, UK
| | - Leonardo Rios-Solis
- Institute for Bioengineering, School of Engineering, University of Edinburgh, Edinburgh, EH9 3JL, UK
- Centre for Synthetic and Systems Biology (SynthSys), University of Edinburgh, King's Buildings, Edinburgh, EH9 3JL, UK
| | - Paul A Dalby
- Department of Biochemical Engineering, University College London, Bernard Katz Building, Gower Street, London, WC1E 6BT, UK.
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5
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Jones K, Snodgrass HM, Belsare K, Dickinson BC, Lewis JC. Phage-Assisted Continuous Evolution and Selection of Enzymes for Chemical Synthesis. ACS CENTRAL SCIENCE 2021; 7:1581-1590. [PMID: 34584960 PMCID: PMC8461764 DOI: 10.1021/acscentsci.1c00811] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/06/2021] [Indexed: 05/04/2023]
Abstract
Ligand-dependent biosensors are valuable tools for coupling the intracellular concentrations of small molecules to easily detectable readouts such as absorbance, fluorescence, or cell growth. While ligand-dependent biosensors are widely used for monitoring the production of small molecules in engineered cells and for controlling or optimizing biosynthetic pathways, their application to directed evolution for biocatalysts remains underexplored. As a consequence, emerging continuous evolution technologies are rarely applied to biocatalyst evolution. Here, we develop a panel of ligand-dependent biosensors that can detect a range of small molecules. We demonstrate that these biosensors can link enzymatic activity to the production of an essential phage protein to enable biocatalyst-dependent phage-assisted continuous evolution (PACE) and phage-assisted continuous selection (PACS). By combining these phage-based evolution and library selection technologies, we demonstrate that we can evolve enzyme variants with improved and expanded catalytic properties. Finally, we show that the genetic diversity resulting from a highly mutated PACS library is enriched for active enzyme variants with altered substrate scope. These results lay the foundation for using phage-based continuous evolution and selection technologies to engineer biocatalysts with novel substrate scope and reactivity.
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Affiliation(s)
- Krysten
A. Jones
- Department
of Chemistry, The University of Chicago, Chicago, Illinois 60637, United States
| | - Harrison M. Snodgrass
- Department
of Chemistry, Indiana University, Bloomington, Indiana 47401, United States
| | - Ketaki Belsare
- Department
of Chemistry, The University of Chicago, Chicago, Illinois 60637, United States
| | - Bryan C. Dickinson
- Department
of Chemistry, The University of Chicago, Chicago, Illinois 60637, United States
- E-mail:
| | - Jared C. Lewis
- Department
of Chemistry, Indiana University, Bloomington, Indiana 47401, United States
- E-mail:
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6
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Cigan E, Eggbauer B, Schrittwieser JH, Kroutil W. The role of biocatalysis in the asymmetric synthesis of alkaloids - an update. RSC Adv 2021; 11:28223-28270. [PMID: 35480754 PMCID: PMC9038100 DOI: 10.1039/d1ra04181a] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2021] [Accepted: 07/30/2021] [Indexed: 12/19/2022] Open
Abstract
Alkaloids are a group of natural products with interesting pharmacological properties and a long history of medicinal application. Their complex molecular structures have fascinated chemists for decades, and their total synthesis still poses a considerable challenge. In a previous review, we have illustrated how biocatalysis can make valuable contributions to the asymmetric synthesis of alkaloids. The chemo-enzymatic strategies discussed therein have been further explored and improved in recent years, and advances in amine biocatalysis have vastly expanded the opportunities for incorporating enzymes into synthetic routes towards these important natural products. The present review summarises modern developments in chemo-enzymatic alkaloid synthesis since 2013, in which the biocatalytic transformations continue to take an increasingly 'central' role.
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Affiliation(s)
- Emmanuel Cigan
- Institute of Chemistry, University of Graz, NAWI Graz, BioTechMed Graz, BioHealth Heinrichstrasse 28/II 8010 Graz Austria
| | - Bettina Eggbauer
- Institute of Chemistry, University of Graz, NAWI Graz, BioTechMed Graz, BioHealth Heinrichstrasse 28/II 8010 Graz Austria
| | - Joerg H Schrittwieser
- Institute of Chemistry, University of Graz, NAWI Graz, BioTechMed Graz, BioHealth Heinrichstrasse 28/II 8010 Graz Austria
| | - Wolfgang Kroutil
- Institute of Chemistry, University of Graz, NAWI Graz, BioTechMed Graz, BioHealth Heinrichstrasse 28/II 8010 Graz Austria
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7
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Liu Q, Xie X, Tang M, Tao W, Shi T, Zhang Y, Huang T, Zhao Y, Deng Z, Lin S. One-Pot Asymmetric Synthesis of an Aminodiol Intermediate of Florfenicol Using Engineered Transketolase and Transaminase. ACS Catal 2021. [DOI: 10.1021/acscatal.1c01229] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Affiliation(s)
- Qi Liu
- State Key Laboratory of Microbial Metabolism, Joint International Research Laboratory on Metabolic & Developmental Sciences, School of Life Sciences & Biotechnology, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai 200240, China
| | - Xinyue Xie
- State Key Laboratory of Microbial Metabolism, Joint International Research Laboratory on Metabolic & Developmental Sciences, School of Life Sciences & Biotechnology, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai 200240, China
| | - Mancheng Tang
- State Key Laboratory of Microbial Metabolism, Joint International Research Laboratory on Metabolic & Developmental Sciences, School of Life Sciences & Biotechnology, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai 200240, China
| | - Wentao Tao
- State Key Laboratory of Microbial Metabolism, Joint International Research Laboratory on Metabolic & Developmental Sciences, School of Life Sciences & Biotechnology, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai 200240, China
| | - Ting Shi
- State Key Laboratory of Microbial Metabolism, Joint International Research Laboratory on Metabolic & Developmental Sciences, School of Life Sciences & Biotechnology, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai 200240, China
| | - Yuanzhen Zhang
- State Key Laboratory of Microbial Metabolism, Joint International Research Laboratory on Metabolic & Developmental Sciences, School of Life Sciences & Biotechnology, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai 200240, China
| | - Tingting Huang
- State Key Laboratory of Microbial Metabolism, Joint International Research Laboratory on Metabolic & Developmental Sciences, School of Life Sciences & Biotechnology, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai 200240, China
| | - Yilei Zhao
- State Key Laboratory of Microbial Metabolism, Joint International Research Laboratory on Metabolic & Developmental Sciences, School of Life Sciences & Biotechnology, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai 200240, China
| | - Zixin Deng
- State Key Laboratory of Microbial Metabolism, Joint International Research Laboratory on Metabolic & Developmental Sciences, School of Life Sciences & Biotechnology, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai 200240, China
| | - Shuangjun Lin
- State Key Laboratory of Microbial Metabolism, Joint International Research Laboratory on Metabolic & Developmental Sciences, School of Life Sciences & Biotechnology, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai 200240, China
- Frontiers Science Center for Transformative Molecules, Shanghai Jiao Tong University, Shanghai 200240, China
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8
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Medina FE, Prejanò M. Water Molecules Allow the Intramolecular Activation of the Thiamine Di-Phosphate Cofactor in Human Transketolase: Mechanistic Insights into a Famous Proposal. ACS Catal 2021. [DOI: 10.1021/acscatal.0c05414] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Affiliation(s)
- Fabiola E. Medina
- Departamento de Ciencias Químicas, Facultad de Ciencias Exactas, Universidad Andres Bello, Autopista Concepción-Talcahuano, Talcahuano 7100, Chile
| | - Mario Prejanò
- Department of Organic Chemistry, Arrhenius Laboratory, Stockholm University, Stockholm SE-10691, Sweden
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9
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Wilkinson HC, Dalby PA. Fine-tuning the activity and stability of an evolved enzyme active-site through noncanonical amino-acids. FEBS J 2020; 288:1935-1955. [PMID: 32897608 DOI: 10.1111/febs.15560] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2020] [Revised: 08/14/2020] [Accepted: 09/02/2020] [Indexed: 01/17/2023]
Abstract
Site-specific saturation mutagenesis within enzyme active sites can radically alter reaction specificity, though often with a trade-off in stability. Extending saturation mutagenesis with a range of noncanonical amino acids (ncAA) potentially increases the ability to improve activity and stability simultaneously. Previously, an Escherichia coli transketolase variant (S385Y/D469T/R520Q) was evolved to accept aromatic aldehydes not converted by wild-type. The aromatic residue Y385 was critical to the new acceptor substrate binding, and so was explored here beyond the natural aromatic residues, to probe side chain structure and electronics effects on enzyme function and stability. A series of five variants introduced decreasing aromatic ring electron density at position 385 in the order para-aminophenylalanine (pAMF), tyrosine (Y), phenylalanine (F), para-cyanophenylalanine (pCNF) and para-nitrophenylalanine (pNTF), and simultaneously modified the hydrogen-bonding potential of the aromatic substituent from accepting to donating. The fine-tuning of residue 385 yielded variants with a 43-fold increase in specific activity for 50 mm 3-HBA and 100% increased kcat (pCNF), 290% improvement in Km (pNTF), 240% improvement in kcat /Km (pAMF) and decreased substrate inhibition relative to Y. Structural modelling suggested switching of the ring-substituted functional group, from donating to accepting, stabilised a helix-turn (D259-H261) through an intersubunit H-bond with G262, to give a 7.8 °C increase in the thermal transition mid-point, Tm , and improved packing of pAMF. This is one of the first examples in which both catalytic activity and stability are simultaneously improved via site-specific ncAA incorporation into an enzyme active site, and further demonstrates the benefits of expanding designer libraries to include ncAAs.
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Affiliation(s)
- Henry C Wilkinson
- Department of Biochemical Engineering, University College London, London, UK
| | - Paul A Dalby
- Department of Biochemical Engineering, University College London, London, UK
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10
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Abstract
On the occasion of Professor Frances H. Arnold's recent acceptance of the 2018 Nobel Prize in Chemistry, we honor her numerous contributions to the fields of directed evolution and biocatalysis. Arnold pioneered the development of directed evolution methods for engineering enzymes as biocatalysts. Her highly interdisciplinary research has provided a ground not only for understanding the mechanisms of enzyme evolution but also for developing commercially viable enzyme biocatalysts and biocatalytic processes. In this Account, we highlight some of her notable contributions in the past three decades in the development of foundational directed evolution methods and their applications in the design and engineering of enzymes with desired functions for biocatalysis. Her work has created a paradigm shift in the broad catalysis field.
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Affiliation(s)
- Rudi Fasan
- Department of Chemistry, University of Rochester, Rochester, New York 14627, United States
| | - S. B. Jennifer Kan
- Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, California 91125, United States
| | - Huimin Zhao
- Departments of Chemical and Biomolecular Engineering, Chemistry, and Biochemistry, Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana−Champaign, Urbana, Illinois 61801, United States
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11
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Ferrario V, Fischer M, Zhu Y, Pleiss J. Modelling of substrate access and substrate binding to cephalosporin acylases. Sci Rep 2019; 9:12402. [PMID: 31455800 PMCID: PMC6712217 DOI: 10.1038/s41598-019-48849-z] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2019] [Accepted: 08/14/2019] [Indexed: 01/16/2023] Open
Abstract
Semisynthetic cephalosporins are widely used antibiotics currently produced by different chemical steps under harsh conditions, which results in a considerable amount of toxic waste. Biocatalytic synthesis by the cephalosporin acylase from Pseudomonas sp. strain N176 is a promising alternative. Despite intensive engineering of the enzyme, the catalytic activity is still too low for a commercially viable process. To identify the bottlenecks which limit the success of protein engineering efforts, a series of MD simulations was performed to study for two acylase variants (WT, M6) the access of the substrate cephalosporin C from the bulk to the active site and the stability of the enzyme-substrate complex. In both variants, cephalosporin C was binding to a non-productive substrate binding site (E86α, S369β, S460β) at the entrance to the binding pocket, preventing substrate access. A second non-productive binding site (G372β, W376β, L457β) was identified within the binding pocket, which competes with the active site for substrate binding. Noteworthy, substrate binding to the protein surface followed a Langmuir model resulting in binding constants K = 7.4 and 9.2 mM for WT and M6, respectively, which were similar to the experimentally determined Michaelis constants KM = 11.0 and 8.1 mM, respectively.
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Affiliation(s)
- Valerio Ferrario
- Institute of Biochemistry and Technical Biochemistry, University of Stuttgart, Allmandring 31, 70569, Stuttgart, Germany
| | - Mona Fischer
- Institute of Biochemistry and Technical Biochemistry, University of Stuttgart, Allmandring 31, 70569, Stuttgart, Germany
| | - Yushan Zhu
- Department of Chemical Engineering, Tsinghua University, Beijing, 100084, China
| | - Jürgen Pleiss
- Institute of Biochemistry and Technical Biochemistry, University of Stuttgart, Allmandring 31, 70569, Stuttgart, Germany.
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12
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Exploiting correlated molecular-dynamics networks to counteract enzyme activity-stability trade-off. Proc Natl Acad Sci U S A 2018; 115:E12192-E12200. [PMID: 30530661 PMCID: PMC6310800 DOI: 10.1073/pnas.1812204115] [Citation(s) in RCA: 52] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Rigidifying flexible sites is a powerful method to improve enzyme stability. However, if the highly flexible regions form the active site, modifying them risks losing activity due to the activity–stability trade-off. We hypothesized here that regions outside the active site whose dynamics were highly correlated to flexible active sites, would provide good targets for stabilizing mutations. To test this hypothesis, six variants were constructed in the 3M variant of Escherichia coli transketolase. The best variant had a 10.8-fold improved half-life at 55 °C, and increased the Tm and Tagg by 3 °C and 4.3 °C, respectively. The variants even increased the activity, by up to threefold. This study highlights how protein engineering strategies could be potentially improved by considering long-range dynamics. The directed evolution of enzymes for improved activity or substrate specificity commonly leads to a trade-off in stability. We have identified an activity–stability trade-off and a loss in unfolding cooperativity for a variant (3M) of Escherichia coli transketolase (TK) engineered to accept aromatic substrates. Molecular dynamics simulations of 3M revealed increased flexibility in several interconnected active-site regions that also form part of the dimer interface. Mutating the newly flexible active-site residues to regain stability risked losing the new activity. We hypothesized that stabilizing mutations could be targeted to residues outside of the active site, whose dynamics were correlated with the newly flexible active-site residues. We previously stabilized WT TK by targeting mutations to highly flexible regions. These regions were much less flexible in 3M and would not have been selected a priori as targets using the same strategy based on flexibility alone. However, their dynamics were highly correlated with the newly flexible active-site regions of 3M. Introducing the previous mutations into 3M reestablished the WT level of stability and unfolding cooperativity, giving a 10.8-fold improved half-life at 55 °C, and increased midpoint and aggregation onset temperatures by 3 °C and 4.3 °C, respectively. Even the activity toward aromatic aldehydes increased up to threefold. Molecular dynamics simulations confirmed that the mutations rigidified the active-site via the correlated network. This work provides insights into the impact of rigidifying mutations within highly correlated dynamic networks that could also be useful for developing improved computational protein engineering strategies.
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13
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Baierl A, Theorell A, Mackfeld U, Marquardt P, Hoffmann F, Moers S, Nöh K, Buchholz PCF, Pleiss J, Pohl M. Towards a Mechanistic Understanding of Factors Controlling the Stereoselectivity of Transketolase. ChemCatChem 2018. [DOI: 10.1002/cctc.201800299] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Anna Baierl
- IBG-1: Biotechnology, Forschungszentrum Jülich GmbH; 52425 Jülich Germany
| | - Axel Theorell
- IBG-1: Biotechnology, Forschungszentrum Jülich GmbH; 52425 Jülich Germany
| | - Ursula Mackfeld
- IBG-1: Biotechnology, Forschungszentrum Jülich GmbH; 52425 Jülich Germany
| | - Philipp Marquardt
- IBG-1: Biotechnology, Forschungszentrum Jülich GmbH; 52425 Jülich Germany
| | | | - Stephanie Moers
- IBG-1: Biotechnology, Forschungszentrum Jülich GmbH; 52425 Jülich Germany
| | - Katharina Nöh
- IBG-1: Biotechnology, Forschungszentrum Jülich GmbH; 52425 Jülich Germany
| | - Patrick C. F. Buchholz
- Institute of Biochemistry and Technical Biochemistry; University of Stuttgart; 70569 Stuttgart Germany
| | - Jürgen Pleiss
- Institute of Biochemistry and Technical Biochemistry; University of Stuttgart; 70569 Stuttgart Germany
| | - Martina Pohl
- IBG-1: Biotechnology, Forschungszentrum Jülich GmbH; 52425 Jülich Germany
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14
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Melis R, Rosini E, Pirillo V, Pollegioni L, Molla G. In vitro evolution of an l-amino acid deaminase active on l-1-naphthylalanine. Catal Sci Technol 2018. [DOI: 10.1039/c8cy01380b] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
l-Amino acid deaminase from Proteus myxofaciens (PmaLAAD) is a promising biocatalyst for enantioselective biocatalysis that can be exploited to produce optically pure d-amino acids or α-keto acids.
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Affiliation(s)
- Roberta Melis
- Dipartimento di Biotecnologie e Scienze della Vita
- Università degli Studi dell'Insubria
- 21100 Varese
- Italy
| | - Elena Rosini
- Dipartimento di Biotecnologie e Scienze della Vita
- Università degli Studi dell'Insubria
- 21100 Varese
- Italy
| | - Valentina Pirillo
- Dipartimento di Biotecnologie e Scienze della Vita
- Università degli Studi dell'Insubria
- 21100 Varese
- Italy
| | - Loredano Pollegioni
- Dipartimento di Biotecnologie e Scienze della Vita
- Università degli Studi dell'Insubria
- 21100 Varese
- Italy
| | - Gianluca Molla
- Dipartimento di Biotecnologie e Scienze della Vita
- Università degli Studi dell'Insubria
- 21100 Varese
- Italy
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