1
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Duran C, Casadevall G, Osuna S. Harnessing conformational dynamics in enzyme catalysis to achieve nature-like catalytic efficiencies: the shortest path map tool for computational enzyme redesign. Faraday Discuss 2024; 252:306-322. [PMID: 38910409 PMCID: PMC11389851 DOI: 10.1039/d3fd00156c] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/25/2024]
Abstract
Enzymes exhibit diverse conformations, as represented in the free energy landscape (FEL). Such conformational diversity provides enzymes with the ability to evolve towards novel functions. The challenge lies in identifying mutations that enhance specific conformational changes, especially if located in distal sites from the active site cavity. The shortest path map (SPM) method, which we developed to address this challenge, constructs a graph based on the distances and correlated motions of residues observed in nanosecond timescale molecular dynamics (MD) simulations. We recently introduced a template based AlphaFold2 (tAF2) approach coupled with 10 nanosecond MD simulations to quickly estimate the conformational landscape of enzymes and assess how the FEL is shifted after mutation. In this study, we evaluate the potential of SPM when coupled with tAF2-MD in estimating conformational heterogeneity and identifying key conformationally-relevant positions. The selected model system is the beta subunit of tryptophan synthase (TrpB). We compare how the SPM pathways differ when integrating tAF2 with different MD simulation lengths from as short as 10 ns until 50 ns and considering two distinct Amber forcefield and water models (ff14SB/TIP3P versus ff19SB/OPC). The new methodology can more effectively capture the distal mutations found in laboratory evolution, thus showcasing the efficacy of tAF2-MD-SPM in rapidly estimating enzyme dynamics and identifying the key conformationally relevant hotspots for computational enzyme engineering.
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Affiliation(s)
- Cristina Duran
- Departament de Química, Institut de Química Computacional i Catàlisi, Universitat de Girona, c/Maria Aurèlia Capmany 69, 17003, Girona, Spain.
| | - Guillem Casadevall
- Departament de Química, Institut de Química Computacional i Catàlisi, Universitat de Girona, c/Maria Aurèlia Capmany 69, 17003, Girona, Spain.
| | - Sílvia Osuna
- Departament de Química, Institut de Química Computacional i Catàlisi, Universitat de Girona, c/Maria Aurèlia Capmany 69, 17003, Girona, Spain.
- ICREA, Pg. Lluís Companys 23, 08010, Barcelona, Spain
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2
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Almhjell PJ, Johnston KE, Porter NJ, Kennemur JL, Bhethanabotla VC, Ducharme J, Arnold FH. The β-subunit of tryptophan synthase is a latent tyrosine synthase. Nat Chem Biol 2024; 20:1086-1093. [PMID: 38744987 PMCID: PMC11288773 DOI: 10.1038/s41589-024-01619-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2023] [Accepted: 04/04/2024] [Indexed: 05/16/2024]
Abstract
Aromatic amino acids and their derivatives are diverse primary and secondary metabolites with critical roles in protein synthesis, cell structure and integrity, defense and signaling. All de novo aromatic amino acid production relies on a set of ancient and highly conserved chemistries. Here we introduce a new enzymatic transformation for L-tyrosine synthesis by demonstrating that the β-subunit of tryptophan synthase-which natively couples indole and L-serine to form L-tryptophan-can act as a latent 'tyrosine synthase'. A single substitution of a near-universally conserved catalytic residue unlocks activity toward simple phenol analogs and yields exclusive para carbon-carbon bond formation to furnish L-tyrosines. Structural and mechanistic studies show how a new active-site water molecule orients phenols for a nonnative mechanism of alkylation, with additional directed evolution resulting in a net >30,000-fold rate enhancement. This new biocatalyst can be used to efficiently prepare valuable L-tyrosine analogs at gram scales and provides the missing chemistry for a conceptually different pathway to L-tyrosine.
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Affiliation(s)
- Patrick J Almhjell
- Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, CA, USA
- Department of Biochemistry, Stanford University, Stanford, CA, USA
| | - Kadina E Johnston
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA, USA
- Merck & Co., Inc, South San Francisco, CA, USA
| | - Nicholas J Porter
- Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, CA, USA
- Codexis, Inc., Redwood City, CA, USA
| | - Jennifer L Kennemur
- Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, CA, USA
| | - Vignesh C Bhethanabotla
- Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, CA, USA
| | - Julie Ducharme
- Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, CA, USA
- Quebec Government Office, Los Angeles, CA, USA
| | - Frances H Arnold
- Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, CA, USA.
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA, USA.
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3
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Scheele R, Weber Y, Nintzel FEH, Herger M, Kaminski TS, Hollfelder F. Ultrahigh Throughput Evolution of Tryptophan Synthase in Droplets via an Aptamer Sensor. ACS Catal 2024; 14:6259-6271. [PMID: 38660603 PMCID: PMC11036396 DOI: 10.1021/acscatal.4c00230] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2024] [Revised: 02/29/2024] [Accepted: 03/25/2024] [Indexed: 04/26/2024]
Abstract
Tryptophan synthase catalyzes the synthesis of a wide array of noncanonical amino acids and is an attractive target for directed evolution. Droplet microfluidics offers an ultrahigh throughput approach to directed evolution (up to 107 experiments per day), enabling the search for biocatalysts in wider regions of sequence space with reagent consumption minimized to the picoliter volume (per library member). While the majority of screening campaigns in this format on record relied on an optically active reaction product, a new assay is needed for tryptophan synthase. Tryptophan is not fluorogenic in the visible light spectrum and thus falls outside the scope of conventional droplet microfluidic readouts, which are incompatible with UV light detection at high throughput. Here, we engineer a tryptophan DNA aptamer into a sensor to quantitatively report on tryptophan production in droplets. The utility of the sensor was validated by identifying five-fold improved tryptophan synthases from ∼100,000 protein variants. More generally, this work establishes the use of DNA-aptamer sensors with a fluorogenic read-out in widening the scope of droplet microfluidic evolution.
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Affiliation(s)
- Remkes
A. Scheele
- Department
of Biochemistry, University of Cambridge, Cambridge CB2 1GA, U.K.
| | - Yanik Weber
- Department
of Biochemistry, University of Cambridge, Cambridge CB2 1GA, U.K.
| | | | - Michael Herger
- Department
of Biochemistry, University of Cambridge, Cambridge CB2 1GA, U.K.
| | - Tomasz S. Kaminski
- Department
of Biochemistry, University of Cambridge, Cambridge CB2 1GA, U.K.
- Department
of Molecular Biology, Institute of Biochemistry, Faculty of Biology, University of Warsaw, 02-096 Warsaw, Poland
| | - Florian Hollfelder
- Department
of Biochemistry, University of Cambridge, Cambridge CB2 1GA, U.K.
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4
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Gao S, Wu XT, Zhang W, Richardson T, Barrow SL, Thompson-Kucera CA, Iavarone AT, Klinman JP. Temporal Resolution of Activity-Related Solvation Dynamics in the TIM Barrel Enzyme Murine Adenosine Deaminase. ACS Catal 2024; 14:4554-4567. [PMID: 39099600 PMCID: PMC11296675 DOI: 10.1021/acscatal.3c02687] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/06/2024]
Abstract
Murine adenosine deaminase (mADA) is a prototypic system for studying the thermal activation of active site chemistry within the TIM barrel family of enzyme reactions. Previous temperature-dependent hydrogen deuterium exchange studies under various conditions have identified interconnected thermal networks for heat transfer from opposing protein-solvent interfaces to active site residues in mADA. One of these interfaces contains a solvent exposed helix-loop-helix moiety that presents the hydrophobic face of its long α-helix to the backside of bound substrate. Herein we pursue the time and temperature dependence of solvation dynamics at the surface of mADA, for comparison to established kinetic parameters that represent active site chemistry. We first created a modified protein devoid of native tryptophans with close to native kinetic behavior. Single site-specific tryptophan mutants were back inserted into each of the four positions where native tryptophans reside. Measurements of nanosecond fluorescence relaxation lifetimes and Stokes shift decays, that reflect time dependent environmental reoroganization around the photo-excited state of Trp*, display minimal temperature dependences. These regions serve as controls for the behavior of a new single tryptophan inserted into a solvent exposed region near the helix-loop-helix moiety located behind the bound substrate, Lys54Trp. This installed Trp displays a significantly elevated value for Ea ( k Stokes shift ) ; further, when Phe61 within the long helix positioned behind bound substrate is replaced by a series of aliphatic hydrophobic side chains, the trends in Ea ( k Stokes shift ) mirror the earlier reported impact of the same series of function-altering hydrophobic side chains on the activation energy of catalysis, Ea ( k cat ) .The reported experimental findings implicate a solvent initiated and rapid (>ns) protein restructuring that contributes to the enthalpic activation barrier to catalysis in mADA.
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Affiliation(s)
- Shuaihua Gao
- Department of Chemistry, University of California, Berkeley, Berkeley, California, 94720, United States
- California Institute for Quantitative Biosciences, and University of California, Berkeley, Berkeley, California, 94720, United States
| | - Xin Ting Wu
- Department of Chemistry, University of California, Berkeley, Berkeley, California, 94720, United States
- California Institute for Quantitative Biosciences, and University of California, Berkeley, Berkeley, California, 94720, United States
| | - Wenju Zhang
- David R. Cheriton School of Computer Science, University of Waterloo, Waterloo, ON N2L 3G1, Canada
| | - Tyre Richardson
- Department of Chemistry, University of California, Berkeley, Berkeley, California, 94720, United States
- California Institute for Quantitative Biosciences, and University of California, Berkeley, Berkeley, California, 94720, United States
| | - Samuel L. Barrow
- Department of Chemistry, University of California, Berkeley, Berkeley, California, 94720, United States
| | - Christian A. Thompson-Kucera
- Department of Chemistry, University of California, Berkeley, Berkeley, California, 94720, United States
- California Institute for Quantitative Biosciences, and University of California, Berkeley, Berkeley, California, 94720, United States
| | - Anthony T. Iavarone
- Department of Chemistry, University of California, Berkeley, Berkeley, California, 94720, United States
- California Institute for Quantitative Biosciences, and University of California, Berkeley, Berkeley, California, 94720, United States
| | - Judith P. Klinman
- Department of Chemistry, University of California, Berkeley, Berkeley, California, 94720, United States
- California Institute for Quantitative Biosciences, and University of California, Berkeley, Berkeley, California, 94720, United States
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, California, 94720, United States
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5
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Brissos V, Borges PT, Sancho F, Lucas MF, Frazão C, Conzuelo F, Martins LO. Flexible active-site loops fine-tune substrate specificity of hyperthermophilic metallo-oxidases. J Biol Inorg Chem 2024; 29:339-351. [PMID: 38227199 PMCID: PMC11111587 DOI: 10.1007/s00775-023-02040-y] [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: 06/12/2023] [Accepted: 11/21/2023] [Indexed: 01/17/2024]
Abstract
Hyperthermophilic ('superheat-loving') archaea found in high-temperature environments such as Pyrobaculum aerophilum contain multicopper oxidases (MCOs) with remarkable efficiency for oxidizing cuprous and ferrous ions. In this work, directed evolution was used to expand the substrate specificity of P. aerophilum McoP for organic substrates. Six rounds of error-prone PCR and DNA shuffling followed by high-throughput screening lead to the identification of a hit variant with a 220-fold increased efficiency (kcat/Km) than the wild-type for 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) without compromising its intrinsic activity for metal ions. The analysis of the X-ray crystal structure reveals four proximal mutations close to the T1Cu active site. One of these mutations is within the 23-residues loop that occludes this site, a distinctive feature of prokaryotic MCOs. The increased flexibility of this loop results in an enlarged tunnel and one additional pocket that facilitates bulky substrate-enzyme interactions. These findings underscore the synergy between mutations that modulate the dynamics of the active-site loop enabling enhanced catalytic function. This study highlights the potential of targeting loops close to the T1Cu for engineering improvements suitable for biotechnological applications.
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Affiliation(s)
- Vânia Brissos
- Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Av da República, 2780-157, Oeiras, Portugal
| | - Patrícia T Borges
- Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Av da República, 2780-157, Oeiras, Portugal
| | - Ferran Sancho
- Zymvol Biomodeling, C/ Pau Claris, 94, 3B, 08010, Barcelona, Spain
| | | | - Carlos Frazão
- Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Av da República, 2780-157, Oeiras, Portugal
| | - Felipe Conzuelo
- Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Av da República, 2780-157, Oeiras, Portugal
| | - Lígia O Martins
- Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Av da República, 2780-157, Oeiras, Portugal.
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6
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Fröhlich C, Bunzel HA, Buda K, Mulholland AJ, van der Kamp MW, Johnsen PJ, Leiros HKS, Tokuriki N. Epistasis arises from shifting the rate-limiting step during enzyme evolution of a β-lactamase. Nat Catal 2024; 7:499-509. [PMID: 38828429 PMCID: PMC11136654 DOI: 10.1038/s41929-024-01117-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2023] [Accepted: 01/25/2024] [Indexed: 06/05/2024]
Abstract
Epistasis, the non-additive effect of mutations, can provide combinatorial improvements to enzyme activity that substantially exceed the gains from individual mutations. Yet the molecular mechanisms of epistasis remain elusive, undermining our ability to predict pathogen evolution and engineer biocatalysts. Here we reveal how directed evolution of a β-lactamase yielded highly epistatic activity enhancements. Evolution selected four mutations that increase antibiotic resistance 40-fold, despite their marginal individual effects (≤2-fold). Synergistic improvements coincided with the introduction of super-stochiometric burst kinetics, indicating that epistasis is rooted in the enzyme's conformational dynamics. Our analysis reveals that epistasis stemmed from distinct effects of each mutation on the catalytic cycle. The initial mutation increased protein flexibility and accelerated substrate binding, which is rate-limiting in the wild-type enzyme. Subsequent mutations predominantly boosted the chemical steps by fine-tuning substrate interactions. Our work identifies an overlooked cause for epistasis: changing the rate-limiting step can result in substantial synergy that boosts enzyme activity.
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Affiliation(s)
| | - H. Adrian Bunzel
- Department of Biosystem Science and Engineering, ETH Zurich, Basel, Switzerland
- Centre for Computational Chemistry, School of Chemistry, University of Bristol, Bristol, UK
- School of Biochemistry, University of Bristol, Bristol, UK
| | - Karol Buda
- Michael Smith Laboratories, University of British Columbia, Vancouver, British Columbia Canada
| | - Adrian J. Mulholland
- Centre for Computational Chemistry, School of Chemistry, University of Bristol, Bristol, UK
| | - Marc W. van der Kamp
- Centre for Computational Chemistry, School of Chemistry, University of Bristol, Bristol, UK
- School of Biochemistry, University of Bristol, Bristol, UK
| | - Pål J. Johnsen
- Department of Pharmacy, UiT The Arctic University of Norway, Tromsø, Norway
| | | | - Nobuhiko Tokuriki
- Michael Smith Laboratories, University of British Columbia, Vancouver, British Columbia Canada
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7
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Rix G, Williams RL, Spinner H, Hu VJ, Marks DS, Liu CC. Continuous evolution of user-defined genes at 1-million-times the genomic mutation rate. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.11.13.566922. [PMID: 38014077 PMCID: PMC10680746 DOI: 10.1101/2023.11.13.566922] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/29/2023]
Abstract
When nature maintains or evolves a gene's function over millions of years at scale, it produces a diversity of homologous sequences whose patterns of conservation and change contain rich structural, functional, and historical information about the gene. However, natural gene diversity likely excludes vast regions of functional sequence space and includes phylogenetic and evolutionary eccentricities, limiting what information we can extract. We introduce an accessible experimental approach for compressing long-term gene evolution to laboratory timescales, allowing for the direct observation of extensive adaptation and divergence followed by inference of structural, functional, and environmental constraints for any selectable gene. To enable this approach, we developed a new orthogonal DNA replication (OrthoRep) system that durably hypermutates chosen genes at a rate of >10 -4 substitutions per base in vivo . When OrthoRep was used to evolve a conditionally essential maladapted enzyme, we obtained thousands of unique multi-mutation sequences with many pairs >60 amino acids apart (>15% divergence), revealing known and new factors influencing enzyme adaptation. The fitness of evolved sequences was not predictable by advanced machine learning models trained on natural variation. We suggest that OrthoRep supports the prospective and systematic discovery of constraints shaping gene evolution, uncovering of new regions in fitness landscapes, and general applications in biomolecular engineering.
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8
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Wang Y, Wang X, Niu S, Cheng W, Liu X, Min Y, Qiu Y, Ma L, Rao B, Zhu L. Improving the Activity of Tryptophan Synthetase via a Nucleic Acid Scaffold. Molecules 2023; 28:7272. [PMID: 37959692 PMCID: PMC10648251 DOI: 10.3390/molecules28217272] [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: 06/10/2023] [Revised: 09/17/2023] [Accepted: 09/25/2023] [Indexed: 11/15/2023] Open
Abstract
Tryptophan synthetase (TSase), which functions as a tetramer, is a typical enzyme with a substrate channel effect, and shows excellent performance in the production of non-standard amino acids, histamine, and other biological derivatives. Based on previous work, we fused a mutant CE protein (colistin of E. coli, a polypeptide with antibacterial activity) sequence with the sequence of TSase to explore whether its catalytic activity could be enhanced, and we also analyzed whether the addition of a DNA scaffold was a feasible strategy. Here, dCE (CE protein without DNase activity) protein tags were constructed and fused to the TrapA and TrapB subunits of TSase, and the whole cell was used for the catalytic reaction. The results showed that after the dCE protein tag was fused to the TrapB subunit, its whole cell catalytic activity increased by 50%. Next, the two subunits were expressed separately, and the proteins were bound in vitro to ensure equimolar combination between the two subunits. After the dCE label was fused to TrapB, the activity of TSase assembled with TrapA also improved. A series of experiments revealed that the enzyme fused with dCE9 showed higher activity than the wild-type protein. In general, the activity of assembly TSase was optimal when the temperature was 50 °C and the pH was about 9.0. After a long temperature treatment, the enzyme maintained good activity. With the addition of exogenous nucleic acid, the activity of the enzyme increased. The maximum yield was 0.58 g/L, which was almost three times that of the wild-type TSase (0.21 g/L). The recombinant TSase constructed in this study with dCE fusion had the advantages of higher heat resistance and higher activity, and confirmed the feasibility of adding a nucleic acid scaffold, providing a new idea for the improvement of structurally similar enzymes.
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Affiliation(s)
- Yaping Wang
- Hubei Biopesticide Engineering Research Center, Hubei Academy of Agricultural Sciences, Biopesticide Branch of Hubei Innovation Centre of Agricultural Science and Technology, Wuhan 430064, China
- State Key Laboratory of Biocatalysis and Enzyme, Engineering Hubei Collaborative Innovation Center for Green Transformation of Bio-Resources, Hubei Key Laboratory of Industrial Biotechnology, Biology Faculty of Hubei University, Hubei University, Wuhan 430062, China
| | - Xiangyi Wang
- Hubei Biopesticide Engineering Research Center, Hubei Academy of Agricultural Sciences, Biopesticide Branch of Hubei Innovation Centre of Agricultural Science and Technology, Wuhan 430064, China
- State Key Laboratory of Biocatalysis and Enzyme, Engineering Hubei Collaborative Innovation Center for Green Transformation of Bio-Resources, Hubei Key Laboratory of Industrial Biotechnology, Biology Faculty of Hubei University, Hubei University, Wuhan 430062, China
| | - Shuhui Niu
- Hubei Biopesticide Engineering Research Center, Hubei Academy of Agricultural Sciences, Biopesticide Branch of Hubei Innovation Centre of Agricultural Science and Technology, Wuhan 430064, China
- State Key Laboratory of Biocatalysis and Enzyme, Engineering Hubei Collaborative Innovation Center for Green Transformation of Bio-Resources, Hubei Key Laboratory of Industrial Biotechnology, Biology Faculty of Hubei University, Hubei University, Wuhan 430062, China
| | - Wei Cheng
- Hubei Biopesticide Engineering Research Center, Hubei Academy of Agricultural Sciences, Biopesticide Branch of Hubei Innovation Centre of Agricultural Science and Technology, Wuhan 430064, China
- State Key Laboratory of Biocatalysis and Enzyme, Engineering Hubei Collaborative Innovation Center for Green Transformation of Bio-Resources, Hubei Key Laboratory of Industrial Biotechnology, Biology Faculty of Hubei University, Hubei University, Wuhan 430062, China
| | - Xiaoyan Liu
- Hubei Biopesticide Engineering Research Center, Hubei Academy of Agricultural Sciences, Biopesticide Branch of Hubei Innovation Centre of Agricultural Science and Technology, Wuhan 430064, China
| | - Yong Min
- Hubei Biopesticide Engineering Research Center, Hubei Academy of Agricultural Sciences, Biopesticide Branch of Hubei Innovation Centre of Agricultural Science and Technology, Wuhan 430064, China
| | - Yimin Qiu
- Hubei Biopesticide Engineering Research Center, Hubei Academy of Agricultural Sciences, Biopesticide Branch of Hubei Innovation Centre of Agricultural Science and Technology, Wuhan 430064, China
| | - Lixin Ma
- State Key Laboratory of Biocatalysis and Enzyme, Engineering Hubei Collaborative Innovation Center for Green Transformation of Bio-Resources, Hubei Key Laboratory of Industrial Biotechnology, Biology Faculty of Hubei University, Hubei University, Wuhan 430062, China
| | - Ben Rao
- Hubei Biopesticide Engineering Research Center, Hubei Academy of Agricultural Sciences, Biopesticide Branch of Hubei Innovation Centre of Agricultural Science and Technology, Wuhan 430064, China
| | - Lei Zhu
- Hubei Biopesticide Engineering Research Center, Hubei Academy of Agricultural Sciences, Biopesticide Branch of Hubei Innovation Centre of Agricultural Science and Technology, Wuhan 430064, China
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9
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Villalona J, Higgins PM, Buller AR. Engineered Biocatalytic Synthesis of β-N-Substituted-α-Amino Acids. Angew Chem Int Ed Engl 2023; 62:e202311189. [PMID: 37625129 PMCID: PMC10592029 DOI: 10.1002/anie.202311189] [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: 08/02/2023] [Revised: 08/24/2023] [Accepted: 08/25/2023] [Indexed: 08/27/2023]
Abstract
Non-canonical amino acids (ncAAs) are useful synthons for the development of new medicines, materials, and probes for bioactivity. Recently, enzyme engineering has been leveraged to produce a suite of highly active enzymes for the synthesis of β-substituted amino acids. However, there are few examples of biocatalytic N-substitution reactions to make α,β-diamino acids. In this study, we used directed evolution to engineer the β-subunit of tryptophan synthase, TrpB, for improved activity with diverse amine nucleophiles. Mechanistic analysis shows that high yields are hindered by product re-entry into the catalytic cycle and subsequent decomposition. Additional equivalents of l-serine can inhibit product reentry through kinetic competition, facilitating preparative scale synthesis. We show β-substitution with a dozen aryl amine nucleophiles, including demonstration on a gram scale. These transformations yield an underexplored class of amino acids that can serve as unique building blocks for chemical biology and medicinal chemistry.
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Affiliation(s)
- Jairo Villalona
- Department of Chemistry, University of Wisconsin, Madison, 1101 University Avenue, Madison, WI 53706, USA
| | - Peyton M Higgins
- Department of Chemistry, University of Wisconsin, Madison, 1101 University Avenue, Madison, WI 53706, USA
| | - Andrew R Buller
- Department of Chemistry, University of Wisconsin, Madison, 1101 University Avenue, Madison, WI 53706, USA
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10
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D'Amico RN, Boehr DD. Allostery, engineering and inhibition of tryptophan synthase. Curr Opin Struct Biol 2023; 82:102657. [PMID: 37467527 DOI: 10.1016/j.sbi.2023.102657] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2023] [Revised: 06/19/2023] [Accepted: 06/21/2023] [Indexed: 07/21/2023]
Abstract
The final two steps of tryptophan biosynthesis are catalyzed by the enzyme tryptophan synthase (TS), composed of alpha (αTS) and beta (βTS) subunits. Recently, experimental and computational methods have mapped "allosteric networks" that connect the αTS and βTS active sites. In αTS, allosteric networks change across the catalytic cycle, which might help drive the conformational changes associated with its function. Directed evolution studies to increase catalytic function and expand the substrate profile of stand-alone βTS have also revealed the importance of αTS in modulating the conformational changes in βTS. These studies also serve as a foundation for the development of TS inhibitors, which can find utility against Mycobacterium tuberculosis and other bacterial pathogens.
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Affiliation(s)
- Rebecca N D'Amico
- Department of Chemistry, Pennsylvania State University, University Park, PA, USA, 16802
| | - David D Boehr
- Department of Chemistry, Pennsylvania State University, University Park, PA, USA, 16802.
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11
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St-Jacques AD, Rodriguez JM, Eason MG, Foster SM, Khan ST, Damry AM, Goto NK, Thompson MC, Chica RA. Computational remodeling of an enzyme conformational landscape for altered substrate selectivity. Nat Commun 2023; 14:6058. [PMID: 37770431 PMCID: PMC10539519 DOI: 10.1038/s41467-023-41762-0] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2023] [Accepted: 09/13/2023] [Indexed: 09/30/2023] Open
Abstract
Structural plasticity of enzymes dictates their function. Yet, our ability to rationally remodel enzyme conformational landscapes to tailor catalytic properties remains limited. Here, we report a computational procedure for tuning conformational landscapes that is based on multistate design of hinge-mediated domain motions. Using this method, we redesign the conformational landscape of a natural aminotransferase to preferentially stabilize a less populated but reactive conformation and thereby increase catalytic efficiency with a non-native substrate, resulting in altered substrate selectivity. Steady-state kinetics of designed variants reveals activity increases with the non-native substrate of approximately 100-fold and selectivity switches of up to 1900-fold. Structural analyses by room-temperature X-ray crystallography and multitemperature nuclear magnetic resonance spectroscopy confirm that conformational equilibria favor the target conformation. Our computational approach opens the door to targeted alterations of conformational states and equilibria, which should facilitate the design of biocatalysts with customized activity and selectivity.
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Affiliation(s)
- Antony D St-Jacques
- Department of Chemistry and Biomolecular Sciences, University of Ottawa, Ottawa, ON, K1N 6N5, Canada
- Center for Catalysis Research and Innovation, University of Ottawa, Ottawa, ON, K1N 6N5, Canada
| | - Joshua M Rodriguez
- Department of Chemistry and Biochemistry, University of California, Merced, Merced, CA, 95343, USA
| | - Matthew G Eason
- Department of Chemistry and Biomolecular Sciences, University of Ottawa, Ottawa, ON, K1N 6N5, Canada
- Center for Catalysis Research and Innovation, University of Ottawa, Ottawa, ON, K1N 6N5, Canada
| | - Scott M Foster
- Department of Chemistry and Biomolecular Sciences, University of Ottawa, Ottawa, ON, K1N 6N5, Canada
- Center for Catalysis Research and Innovation, University of Ottawa, Ottawa, ON, K1N 6N5, Canada
| | - Safwat T Khan
- Department of Chemistry and Biomolecular Sciences, University of Ottawa, Ottawa, ON, K1N 6N5, Canada
- Center for Catalysis Research and Innovation, University of Ottawa, Ottawa, ON, K1N 6N5, Canada
| | - Adam M Damry
- Department of Chemistry and Biomolecular Sciences, University of Ottawa, Ottawa, ON, K1N 6N5, Canada
- Center for Catalysis Research and Innovation, University of Ottawa, Ottawa, ON, K1N 6N5, Canada
| | - Natalie K Goto
- Department of Chemistry and Biomolecular Sciences, University of Ottawa, Ottawa, ON, K1N 6N5, Canada
- Center for Catalysis Research and Innovation, University of Ottawa, Ottawa, ON, K1N 6N5, Canada
| | - Michael C Thompson
- Department of Chemistry and Biochemistry, University of California, Merced, Merced, CA, 95343, USA
| | - Roberto A Chica
- Department of Chemistry and Biomolecular Sciences, University of Ottawa, Ottawa, ON, K1N 6N5, Canada.
- Center for Catalysis Research and Innovation, University of Ottawa, Ottawa, ON, K1N 6N5, Canada.
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12
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Jeong WJ, Lee J, Eom H, Song WJ. A Specific Guide for Metalloenzyme Designers: Introduction and Evolution of Metal-Coordination Spheres Embedded in Protein Environments. Acc Chem Res 2023; 56:2416-2425. [PMID: 37643364 DOI: 10.1021/acs.accounts.3c00336] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/31/2023]
Affiliation(s)
- Woo Jae Jeong
- Department of Chemistry, Seoul National University, Seoul 08826, Republic of Korea
| | - Jaehee Lee
- Department of Chemistry, Seoul National University, Seoul 08826, Republic of Korea
| | - Hyunuk Eom
- Department of Chemistry, Seoul National University, Seoul 08826, Republic of Korea
| | - Woon Ju Song
- Department of Chemistry, Seoul National University, Seoul 08826, Republic of Korea
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13
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Cheng L, Li D, Mai BK, Bo Z, Cheng L, Liu P, Yang Y. Stereoselective amino acid synthesis by synergistic photoredox-pyridoxal radical biocatalysis. Science 2023; 381:444-451. [PMID: 37499030 PMCID: PMC10444520 DOI: 10.1126/science.adg2420] [Citation(s) in RCA: 26] [Impact Index Per Article: 26.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2022] [Accepted: 06/20/2023] [Indexed: 07/29/2023]
Abstract
Developing synthetically useful enzymatic reactions that are not known in biochemistry and organic chemistry is an important challenge in biocatalysis. Through the synergistic merger of photoredox catalysis and pyridoxal 5'-phosphate (PLP) biocatalysis, we developed a pyridoxal radical biocatalysis approach to prepare valuable noncanonical amino acids, including those bearing a stereochemical dyad or triad, without the need for protecting groups. Using engineered PLP enzymes, either enantiomeric product could be produced in a biocatalyst-controlled fashion. Synergistic photoredox-pyridoxal radical biocatalysis represents a powerful platform with which to discover previously unknown catalytic reactions and to tame radical intermediates for asymmetric catalysis.
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Affiliation(s)
- Lei Cheng
- Department of Chemistry and Biochemistry, University of California Santa Barbara, Santa Barbara, California 93106, USA
| | - Dian Li
- Department of Chemistry and Biochemistry, University of California Santa Barbara, Santa Barbara, California 93106, USA
| | - Binh Khanh Mai
- Department of Chemistry, University of Pittsburgh, Pittsburgh, Pennsylvania 15260, USA
| | - Zhiyu Bo
- Department of Chemistry and Biochemistry, University of California Santa Barbara, Santa Barbara, California 93106, USA
| | - Lida Cheng
- Department of Chemistry and Biochemistry, University of California Santa Barbara, Santa Barbara, California 93106, USA
| | - Peng Liu
- Department of Chemistry, University of Pittsburgh, Pittsburgh, Pennsylvania 15260, USA
| | - Yang Yang
- Department of Chemistry and Biochemistry, University of California Santa Barbara, Santa Barbara, California 93106, USA
- Biomolecular Science and Engineering (BMSE) Program, University of California Santa Barbara, Santa Barbara, California 93106, USA
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14
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Kish M, Subramanian S, Smith V, Lethbridge N, Cole L, Vollmer F, Bond NJ, Phillips JJ. Allosteric Regulation of Glycogen Phosphorylase by Order/Disorder Transition of the 250' and 280s Loops. Biochemistry 2023; 62:1360-1368. [PMID: 36989206 PMCID: PMC10116597 DOI: 10.1021/acs.biochem.2c00671] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/30/2023]
Abstract
Allostery is a fundamental mechanism of protein activation, yet the precise dynamic changes that underlie functional regulation of allosteric enzymes, such as glycogen phosphorylase (GlyP), remain poorly understood. Despite being the first allosteric enzyme described, its structural regulation is still a challenging problem: the key regulatory loops of the GlyP active site (250' and 280s) are weakly stable and often missing density or have large b-factors in structural models. This led to the longstanding hypothesis that GlyP regulation is achieved through gating of the active site by (dis)order transitions, as first proposed by Barford and Johnson. However, testing this requires a quantitative measurement of weakly stable local structure which, to date, has been technically challenging in such a large protein. Hydrogen-deuterium-exchange mass spectrometry (HDX-MS) is a powerful tool for studying protein dynamics, and millisecond HDX-MS has the ability to measure site-localized stability differences in weakly stable structures, making it particularly valuable for investigating allosteric regulation in GlyP. Here, we used millisecond HDX-MS to measure the local structural perturbations of glycogen phosphorylase b (GlyPb), the phosphorylated active form (GlyPa), and the inhibited glucose-6 phosphate complex (GlyPb:G6P) at near-amino acid resolution. Our results support the Barford and Johnson hypothesis for GlyP regulation by providing insight into the dynamic changes of the key regulatory loops.
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Affiliation(s)
- Monika Kish
- Living Systems Institute, Department of Biosciences, University of Exeter, Stocker Road, Exeter, EX4 4QD, U.K
| | - Sivaraman Subramanian
- Living Systems Institute, Department of Physics, University of Exeter, Stocker Road, Exeter, EX4 6QD, U.K
| | | | | | - Lindsay Cole
- Applied Photophysics Ltd, Leatherhead, KT227BA, U.K
| | - Frank Vollmer
- Living Systems Institute, Department of Physics, University of Exeter, Stocker Road, Exeter, EX4 6QD, U.K
| | - Nicholas J Bond
- Analytical Sciences, Biopharmaceutical Development, BioPharmaceuticals R&D, AstraZeneca, Milstein Building, Granta Park, Cambridge, CB21 6GH, U.K
| | - Jonathan J Phillips
- Living Systems Institute, Department of Biosciences, University of Exeter, Stocker Road, Exeter, EX4 4QD, U.K
- Alan Turing Institute, British Library, London, NW1 2DB, U.K
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15
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Panigrahi R, Kailasam S. Mapping allosteric pathway in NIa-Pro using computational approach. QUANTITATIVE BIOLOGY 2023. [DOI: 10.15302/j-qb-022-0296] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
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16
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Li S, Yang H, Hofstetter H, Tonelli M, Cavagnero S. Magnetic-Field Dependence of LC-Photo-CIDNP in the Presence of Target Molecules Carrying a Quasi-Isolated Spin Pair. APPLIED MAGNETIC RESONANCE 2023; 54:59-75. [PMID: 37483563 PMCID: PMC10358788 DOI: 10.1007/s00723-022-01506-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/01/2022] [Revised: 09/04/2022] [Accepted: 09/30/2022] [Indexed: 07/25/2023]
Abstract
NMR spectroscopy is well known for its superb resolution, especially at high applied magnetic field. However, the sensitivity of this technique is very low. Liquid-state low-concentration photo-chemically-induced dynamic nuclear polarization (LC-photo-CIDNP) is a promising emerging methodology capable of enhancing NMR sensitivity in solution. LC-photo-CIDNP works well on solvent-exposed Trp and Tyr residues, either in isolation or within proteins. This study explores the magnetic-field dependence of the LC-photo-CIDNP experienced by two tryptophan isotopologs in solution upon in situ LED-mediated optical irradiation. Out of the two uniformly 13C,15N-labeled Trp (Trp-U-13C,15N) and Trp-α-13C-β,β,2,4,5,6,7-d7 species employed here, only the latter bears a quasi-isolated 1Hα-13Cα spin pair. Computer simulations of the predicted polarization due to geminate recombination of both species display a roughly bell-shaped field dependence. However, while Trp-U-13C,15N is predicted to show a maximum at ca. 500 MHz (11.7 T) and a fairly weak field dependence, Trp-α-13C-β,β,2,4,5,6,7-d7 is expected to display a much sharper field dependence accompanied by a dramatic polarization increase at lower field (ca. 200 MHz, 4.7 T). Experimental LC-photo-CIDNP studies on both Trp isotopologs at 1μM concentration, performed at selected fields, are consistent with the theoretical predictions. In summary, this study highlights the prominent field-dependence of LC-photo-CIDNP enhancements (ε ) experienced by Trp isotopologs bearing a quasi-isolated spin pair.
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Affiliation(s)
- Siyu Li
- Department of Chemistry, University of Wisconsin - Madison, 1101 University Ave., Madison, Wisconsin, 53706, USA
| | - Hanming Yang
- Department of Chemistry, University of Wisconsin - Madison, 1101 University Ave., Madison, Wisconsin, 53706, USA
| | - Heike Hofstetter
- Department of Chemistry, University of Wisconsin - Madison, 1101 University Ave., Madison, Wisconsin, 53706, USA
| | - Marco Tonelli
- Department of Biochemistry, University of Wisconsin-Madison, 433 Babcock Drive, Madison, Wisconsin, 53706, USA
| | - Silvia Cavagnero
- Department of Chemistry, University of Wisconsin - Madison, 1101 University Ave., Madison, Wisconsin, 53706, USA
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17
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Blazeck J, Karamitros CS, Ford K, Somody C, Qerqez A, Murray K, Burkholder NT, Marshall N, Sivakumar A, Lu WC, Tan B, Lamb C, Tanno Y, Siddiqui MY, Ashoura N, Coma S, Zhang XM, McGovern K, Kumada Y, Zhang YJ, Manfredi M, Johnson KA, D’Arcy S, Stone E, Georgiou G. Bypassing evolutionary dead ends and switching the rate-limiting step of a human immunotherapeutic enzyme. Nat Catal 2022; 5:952-967. [PMID: 36465553 PMCID: PMC9717613 DOI: 10.1038/s41929-022-00856-6] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2021] [Accepted: 09/09/2022] [Indexed: 11/08/2022]
Abstract
The Trp metabolite kynurenine (KYN) accumulates in numerous solid tumours and mediates potent immunosuppression. Bacterial kynureninases (KYNases), which preferentially degrade kynurenine, can relieve immunosuppression in multiple cancer models, but immunogenicity concerns preclude their clinical use, while the human enzyme (HsKYNase) has very low activity for kynurenine and shows no therapeutic effect. Using fitness selections, we evolved a HsKYNase variant with 27-fold higher activity, beyond which exploration of >30 evolutionary trajectories involving the interrogation of >109 variants led to no further improvements. Introduction of two amino acid substitutions conserved in bacterial KYNases reduced enzyme fitness but potentiated rapid evolution of variants with ~500-fold improved activity and reversed substrate specificity, resulting in an enzyme capable of mediating strong anti-tumour effects in mice. Pre-steady-state kinetics revealed a switch in rate-determining step attributable to changes in both enzyme structure and conformational dynamics. Apart from its clinical significance, our work highlights how rationally designed substitutions can potentiate trajectories that overcome barriers in protein evolution.
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Affiliation(s)
- John Blazeck
- Department of Chemical Engineering, University of Texas at Austin (UT Austin), Austin, Texas, USA
| | - Christos S. Karamitros
- Department of Chemical Engineering, University of Texas at Austin (UT Austin), Austin, Texas, USA
| | - Kyle Ford
- Department of Chemical Engineering, University of Texas at Austin (UT Austin), Austin, Texas, USA
| | - Catrina Somody
- Department of Chemical Engineering, University of Texas at Austin (UT Austin), Austin, Texas, USA
| | - Ahlam Qerqez
- Department of Chemical Engineering, University of Texas at Austin (UT Austin), Austin, Texas, USA
| | - Kyle Murray
- Department of Chemistry and Biochemistry, The University of Texas at Dallas, Richardson, Texas, USA
| | - Nathaniel T. Burkholder
- Department of Molecular Biosciences, University of Texas at Austin (UT Austin), Austin, Texas, USA
| | - Nicholas Marshall
- Department of Chemical Engineering, University of Texas at Austin (UT Austin), Austin, Texas, USA
| | - Anirudh Sivakumar
- Department of Chemical Engineering, University of Texas at Austin (UT Austin), Austin, Texas, USA
| | - Wei-Cheng Lu
- Department of Chemical Engineering, University of Texas at Austin (UT Austin), Austin, Texas, USA
| | - Bing Tan
- Department of Chemical Engineering, University of Texas at Austin (UT Austin), Austin, Texas, USA
| | - Candice Lamb
- Department of Chemical Engineering, University of Texas at Austin (UT Austin), Austin, Texas, USA
| | - Yuri Tanno
- Department of Chemical Engineering, University of Texas at Austin (UT Austin), Austin, Texas, USA
| | - Menna Y. Siddiqui
- Department of Chemical Engineering, University of Texas at Austin (UT Austin), Austin, Texas, USA
| | - Norah Ashoura
- Department of Molecular Biosciences, University of Texas at Austin (UT Austin), Austin, Texas, USA
| | - Silvia Coma
- Ikena Oncology, Cambridge, Massachusetts, USA
| | | | | | - Yoichi Kumada
- Department of Molecular Chemistry and Engineering, Kyoto Institute of Technology, Kyoto, Japan
| | - Yan Jessie Zhang
- Department of Molecular Biosciences, University of Texas at Austin (UT Austin), Austin, Texas, USA
- Institute for Cellular and Molecular Biology, The University of Texas at Austin (UT Austin), Austin, Texas, USA
| | | | - Kenneth A. Johnson
- Department of Molecular Biosciences, University of Texas at Austin (UT Austin), Austin, Texas, USA
| | - Sheena D’Arcy
- Department of Chemistry and Biochemistry, The University of Texas at Dallas, Richardson, Texas, USA
| | - Everett Stone
- Department of Molecular Biosciences, University of Texas at Austin (UT Austin), Austin, Texas, USA
- Institute for Cellular and Molecular Biology, The University of Texas at Austin (UT Austin), Austin, Texas, USA
- Department of Oncology, University of Texas Dell Medical School, LiveSTRONG Cancer Institutes, Austin, Texas, USA
| | - George Georgiou
- Department of Chemical Engineering, University of Texas at Austin (UT Austin), Austin, Texas, USA
- Department of Molecular Biosciences, University of Texas at Austin (UT Austin), Austin, Texas, USA
- Institute for Cellular and Molecular Biology, The University of Texas at Austin (UT Austin), Austin, Texas, USA
- Department of Oncology, University of Texas Dell Medical School, LiveSTRONG Cancer Institutes, Austin, Texas, USA
- Department of Biomedical Engineering, University of Texas at Austin (UT Austin), Austin, TX, USA
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18
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Casadevall G, Duran C, Estévez‐Gay M, Osuna S. Estimating conformational heterogeneity of tryptophan synthase with a template-based Alphafold2 approach. Protein Sci 2022; 31:e4426. [PMID: 36173176 PMCID: PMC9601780 DOI: 10.1002/pro.4426] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2022] [Revised: 07/29/2022] [Accepted: 08/15/2022] [Indexed: 11/10/2022]
Abstract
The three-dimensional structure of the enzymes provides very relevant information on the arrangement of the catalytic machinery and structural elements gating the active site pocket. The recent success of the neural network Alphafold2 in predicting the folded structure of proteins from the primary sequence with high levels of accuracy has revolutionized the protein design field. However, the application of Alphafold2 for understanding and engineering function directly from the obtained single static picture is not straightforward. Indeed, understanding enzymatic function requires the exploration of the ensemble of thermally accessible conformations that enzymes adopt in solution. In the present study, we evaluate the potential of Alphafold2 in assessing the effect of the mutations on the conformational landscape of the beta subunit of tryptophan synthase (TrpB). Specifically, we develop a template-based Alphafold2 approach for estimating the conformational heterogeneity of several TrpB enzymes, which is needed for enhanced stand-alone activity. Our results show the potential of Alphafold2, especially if combined with molecular dynamics simulations, for elucidating the changes induced by mutation in the conformational landscapes at a rather reduced computational cost, thus revealing its plausible application in computational enzyme design.
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Affiliation(s)
- Guillem Casadevall
- CompBioLab Group, Institut de Química Computacional i Catàlisi and Departament de QuímicaUniversitat de GironaGironaSpain
| | - Cristina Duran
- CompBioLab Group, Institut de Química Computacional i Catàlisi and Departament de QuímicaUniversitat de GironaGironaSpain
| | - Miquel Estévez‐Gay
- CompBioLab Group, Institut de Química Computacional i Catàlisi and Departament de QuímicaUniversitat de GironaGironaSpain
| | - Sílvia Osuna
- CompBioLab Group, Institut de Química Computacional i Catàlisi and Departament de QuímicaUniversitat de GironaGironaSpain
- ICREABarcelonaSpain
- Present address:
ICREA, Pg. Lluís Companys 23, 08010BarcelonaSpain
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19
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Substrate multiplexed protein engineering facilitates promiscuous biocatalytic synthesis. Nat Commun 2022; 13:5242. [PMID: 36068220 PMCID: PMC9448781 DOI: 10.1038/s41467-022-32789-w] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2022] [Accepted: 08/17/2022] [Indexed: 11/19/2022] Open
Abstract
Enzymes with high activity are readily produced through protein engineering, but intentionally and efficiently engineering enzymes for an expanded substrate scope is a contemporary challenge. One approach to address this challenge is Substrate Multiplexed Screening (SUMS), where enzyme activity is measured on competing substrates. SUMS has long been used to rigorously quantitate native enzyme specificity, primarily for in vivo settings. SUMS has more recently found sporadic use as a protein engineering approach but has not been widely adopted by the field, despite its potential utility. Here, we develop principles of how to design and interpret SUMS assays to guide protein engineering. This rich information enables improving activity with multiple substrates simultaneously, identifies enzyme variants with altered scope, and indicates potential mutational hot-spots as sites for further engineering. These advances leverage common laboratory equipment and represent a highly accessible and customizable method for enzyme engineering. Efficient engineering of enzymes for expanded substrate scope is currently challenging. Here, the authors develop simple principles of how to design and interpret Substrate Multiplexed Screening assays to guide protein engineering to enable activity improvements with simultaneously with multiple substrates.
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20
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Gao S, Klinman JP. Functional roles of enzyme dynamics in accelerating active site chemistry: Emerging techniques and changing concepts. Curr Opin Struct Biol 2022; 75:102434. [PMID: 35872562 PMCID: PMC9901422 DOI: 10.1016/j.sbi.2022.102434] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2022] [Revised: 06/15/2022] [Accepted: 06/21/2022] [Indexed: 02/08/2023]
Abstract
With the growing acceptance of the contribution of protein conformational ensembles to enzyme catalysis and regulation, research in the field of protein dynamics has shifted toward an understanding of the atomistic properties of protein dynamical networks and the mechanisms and time scales that control such behavior. A full description of an enzymatic reaction coordinate is expected to extend beyond the active site and include site-specific networks that communicate with the protein/water interface. Advances in experimental tools for the spatial resolution of thermal activation pathways are being complemented by biophysical methods for visualizing dynamics in real time. An emerging multidimensional model integrates the impacts of bound substrate/effector on the distribution of protein substates that are in rapid equilibration near room temperature with reaction-specific protein embedded heat transfer conduits.
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Affiliation(s)
- Shuaihua Gao
- Department of Chemistry, University of California, Berkeley, CA, 94720, United States; California Institute for Quantitative Biosciences, University of California, Berkeley, CA, 94720, United States. https://twitter.com/S_H_Gao
| | - Judith P Klinman
- Department of Chemistry, University of California, Berkeley, CA, 94720, United States; California Institute for Quantitative Biosciences, University of California, Berkeley, CA, 94720, United States; Department of Molecular and Cell Biology, University of California, Berkeley, CA, 94720, United States.
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21
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Mai BK, Neris NM, Yang Y, Liu P. C-N Bond Forming Radical Rebound Is the Enantioselectivity-Determining Step in P411-Catalyzed Enantioselective C(sp 3)-H Amination: A Combined Computational and Experimental Investigation. J Am Chem Soc 2022; 144:11215-11225. [PMID: 35583461 DOI: 10.1021/jacs.2c02283] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Engineered metalloenzymes represent promising catalysts for stereoselective C-H functionalization reactions. Recently, P450 enzymes have been evolved to allow for new-to-nature intramolecular C(sp3)-H amination reactions via a nitrene transfer mechanism, giving rise to diamine derivatives with excellent enantiocontrol. To shed light on the origin of enantioselectivity, a combined computational and experimental study was carried out. Hybrid quantum mechanics/molecular mechanics calculations were performed to investigate the activation energies and enantioselectivities of both the hydrogen atom transfer (HAT) and the subsequent C-N bond forming radical rebound steps. Contrary to previously hypothesized enantioinduction mechanisms, our calculations show that the radical rebound step is enantioselectivity-determining, whereas the preceding HAT step is only moderately stereoselective. Furthermore, the selectivity in the initial HAT is ablated by rapid conformational change of the radical intermediate prior to C-N bond formation. This finding is corroborated by our experimental study using a set of enantiomerically pure, monodeuterated substrates. Furthermore, classical and ab initio molecular dynamics simulations were carried out to investigate the conformational flexibility of the carbon-centered radical intermediate. This key radical species undergoes a facile conformational change in the enzyme active site from the pro-(R) to the pro-(S) configuration, whereas the radical rebound is slower due to the spin-state change and ring strain of the cyclization process, thereby allowing stereoablative C-N bond formation. Together, these studies revealed an underappreciated enantioinduction mechanism in biocatalytic C(sp3)-H functionalizations involving radical intermediates, opening up new avenues for the development of other challenging asymmetric C(sp3)-H functionalizations.
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Affiliation(s)
- Binh Khanh Mai
- Department of Chemistry, University of Pittsburgh, Pittsburgh, Pennsylvania 15260, United States
| | - Natalia M Neris
- Department of Chemistry and Biochemistry, University of California, Santa Barbara, California 93106, United States
| | - Yang Yang
- Department of Chemistry and Biochemistry, University of California, Santa Barbara, California 93106, United States
- Biomolecular Science and Engineering (BMSE) Program, University of California, Santa Barbara, California 93106, United States
| | - Peng Liu
- Department of Chemistry, University of Pittsburgh, Pittsburgh, Pennsylvania 15260, United States
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22
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Pan Y, Bao J, Zhang X, Ni H, Zhao Y, Zhi F, Fang B, He X, Zhang JZH, Zhang L. Rational Design of P450 aMOx for Improving Anti-Markovnikov Selectivity Based on the “Butterfly” Model. Front Mol Biosci 2022; 9:888721. [PMID: 35677881 PMCID: PMC9168652 DOI: 10.3389/fmolb.2022.888721] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2022] [Accepted: 04/15/2022] [Indexed: 11/13/2022] Open
Abstract
Aromatic aldehydes are important industrial raw materials mainly synthesized by anti-Markovnikov (AM) oxidation of corresponding aromatic olefins. The AM product selectivity remains a big challenge. P450 aMOx is the first reported enzyme that could catalyze AM oxidation of aromatic olefins. Here, we reported a rational design strategy based on the “butterfly” model of the active site of P450 aMOx. Constrained molecular dynamic simulations and a binding energy analysis of key residuals combined with an experimental alanine scan were applied. As a result, the mutant A275G showed high AM selectivity of >99%. The results also proved that the “butterfly” model is an effective design strategy for enzymes.
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Affiliation(s)
- Yue Pan
- Shanghai Engineering Research Center of Molecular Therapeutics and New Drug Development, Shanghai Key Laboratory of Green Chemistry and Chemical Process, School of Chemistry and Molecular Engineering, East China Normal University, Shanghai, China
| | - Jinxiao Bao
- Shanghai Engineering Research Center of Molecular Therapeutics and New Drug Development, Shanghai Key Laboratory of Green Chemistry and Chemical Process, School of Chemistry and Molecular Engineering, East China Normal University, Shanghai, China
| | - Xingyi Zhang
- College of Food and Biological Engineering, Jimei University, Xiamen, China
| | - Hui Ni
- College of Food and Biological Engineering, Jimei University, Xiamen, China
| | - Yue Zhao
- Shanghai Engineering Research Center of Molecular Therapeutics and New Drug Development, Shanghai Key Laboratory of Green Chemistry and Chemical Process, School of Chemistry and Molecular Engineering, East China Normal University, Shanghai, China
| | - Fengdong Zhi
- Shanghai Engineering Research Center of Molecular Therapeutics and New Drug Development, Shanghai Key Laboratory of Green Chemistry and Chemical Process, School of Chemistry and Molecular Engineering, East China Normal University, Shanghai, China
| | - Bohuan Fang
- Shanghai Engineering Research Center of Molecular Therapeutics and New Drug Development, Shanghai Key Laboratory of Green Chemistry and Chemical Process, School of Chemistry and Molecular Engineering, East China Normal University, Shanghai, China
| | - Xiao He
- Shanghai Engineering Research Center of Molecular Therapeutics and New Drug Development, Shanghai Key Laboratory of Green Chemistry and Chemical Process, School of Chemistry and Molecular Engineering, East China Normal University, Shanghai, China
- NYU-ECNU Center for Computational Chemistry at NYU Shanghai, Shanghai, China
- *Correspondence: Xiao He, ; John Z. H. Zhang, ; Lujia Zhang,
| | - John Z. H. Zhang
- Shanghai Engineering Research Center of Molecular Therapeutics and New Drug Development, Shanghai Key Laboratory of Green Chemistry and Chemical Process, School of Chemistry and Molecular Engineering, East China Normal University, Shanghai, China
- NYU-ECNU Center for Computational Chemistry at NYU Shanghai, Shanghai, China
- Department of Chemistry, New York University, New York, NY, United States
- *Correspondence: Xiao He, ; John Z. H. Zhang, ; Lujia Zhang,
| | - Lujia Zhang
- Shanghai Engineering Research Center of Molecular Therapeutics and New Drug Development, Shanghai Key Laboratory of Green Chemistry and Chemical Process, School of Chemistry and Molecular Engineering, East China Normal University, Shanghai, China
- NYU-ECNU Center for Computational Chemistry at NYU Shanghai, Shanghai, China
- *Correspondence: Xiao He, ; John Z. H. Zhang, ; Lujia Zhang,
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23
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l-Serine Biosensor-Controlled Fermentative Production of l-Tryptophan Derivatives by Corynebacterium glutamicum. BIOLOGY 2022; 11:biology11050744. [PMID: 35625472 PMCID: PMC9138238 DOI: 10.3390/biology11050744] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/05/2022] [Revised: 05/05/2022] [Accepted: 05/10/2022] [Indexed: 11/17/2022]
Abstract
Simple Summary l-tryptophan is an amino acid found in proteins. Its derivatives, such as hydroxylated or halogenated l-tryptophans, find applications in the chemical and pharmaceutical industries, for example, in therapeutic peptides. Biotechnology provides a sustainable way for the production of l-tryptophan and its derivatives. In the final reaction of l-tryptophan biosynthesis in bacteria, such as Corynebacterium glutamicum, another amino acid, l-serine, is incorporated. Here, we show that C. glutamicum TrpB is able to convert indole derivatives, which were added to cells synthesizing l-serine, to the corresponding l-tryptophan derivatives. The gene trpB was expressed under the control of the l-serine-responsive transcriptional activator SerR in the C. glutamicum cells engineered for this fermentation process. Abstract l-Tryptophan derivatives, such as hydroxylated or halogenated l-tryptophans, are used in therapeutic peptides and agrochemicals and as precursors of bioactive compounds, such as serotonin. l-Tryptophan biosynthesis depends on another proteinogenic amino acid, l-serine, which is condensed with indole-3-glycerophosphate by tryptophan synthase. This enzyme is composed of the α-subunit TrpA, which catalyzes the retro-aldol cleavage of indole-3-glycerol phosphate, yielding glyceraldehyde-3-phosphate and indole, and the β-subunit TrpB that catalyzes the β-substitution reaction between indole and l-serine to water and l-tryptophan. TrpA is reported as an allosteric actuator, and its absence severely attenuates TrpB activity. In this study, however, we showed that Corynebacterium glutamicum TrpB is catalytically active in the absence of TrpA. Overexpression of C. glutamicumtrpB in a trpBA double deletion mutant supported growth in minimal medium only when exogenously added indole was taken up into the cell and condensed with intracellularly synthesized l-serine. The fluorescence reporter gene of an l-serine biosensor, which was based on the endogenous transcriptional activator SerR and its target promoter PserE, was replaced by trpB. This allowed for l-serine-dependent expression of trpB in an l-serine-producing strain lacking TrpA. Upon feeding of the respective indole derivatives, this strain produced the l-tryptophan derivatives 5-hydroxytryptophan, 7-bromotryptophan, and 5-fluorotryptophan.
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24
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Brissos V, Borges P, Núñez-Franco R, Lucas MF, Frazão C, Monza E, Masgrau L, Cordeiro TN, Martins LO. Distal Mutations Shape Substrate-Binding Sites during Evolution of a Metallo-Oxidase into a Laccase. ACS Catal 2022; 12:5022-5035. [PMID: 36567772 PMCID: PMC9775220 DOI: 10.1021/acscatal.2c00336] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Laccases are in increasing demand as innovative solutions in the biorefinery fields. Here, we combine mutagenesis with structural, kinetic, and in silico analyses to characterize the molecular features that cause the evolution of a hyperthermostable metallo-oxidase from the multicopper oxidase family into a laccase (k cat 273 s-1 for a bulky aromatic substrate). We show that six mutations scattered across the enzyme collectively modulate dynamics to improve the binding and catalysis of a bulky aromatic substrate. The replacement of residues during the early stages of evolution is a stepping stone for altering the shape and size of substrate-binding sites. Binding sites are then fine-tuned through high-order epistasis interactions by inserting distal mutations during later stages of evolution. Allosterically coupled, long-range dynamic networks favor catalytically competent conformational states that are more suitable for recognizing and stabilizing the aromatic substrate. This work provides mechanistic insight into enzymatic and evolutionary molecular mechanisms and spots the importance of iterative experimental and computational analyses to understand local-to-global changes.
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Affiliation(s)
- Vânia Brissos
- Instituto
de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Av da República, 2780-157 Oeiras, Portugal
| | - Patrícia
T. Borges
- Instituto
de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Av da República, 2780-157 Oeiras, Portugal
| | | | | | - Carlos Frazão
- Instituto
de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Av da República, 2780-157 Oeiras, Portugal
| | - Emanuele Monza
- Zymvol
Biomodeling, Carrer Roc
Boronat, 117, 08018 Barcelona, Spain
| | - Laura Masgrau
- Zymvol
Biomodeling, Carrer Roc
Boronat, 117, 08018 Barcelona, Spain,Department
of Chemistry, Universitat Autònoma
de Barcelona, 08193 Bellaterra, Spain
| | - Tiago N. Cordeiro
- Instituto
de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Av da República, 2780-157 Oeiras, Portugal
| | - Lígia O. Martins
- Instituto
de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Av da República, 2780-157 Oeiras, Portugal,
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25
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Zhang J, Su C, Kong XL, Gong JS, Liu YL, Li H, Qin J, Xu ZH, Shi JS. Directed evolution driving the generation of an efficient keratinase variant to facilitate the feather degradation. BIORESOUR BIOPROCESS 2022; 9:38. [PMID: 38647843 PMCID: PMC10992214 DOI: 10.1186/s40643-022-00524-4] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2022] [Accepted: 03/12/2022] [Indexed: 11/10/2022] Open
Abstract
Keratinases can specifically degrade keratins, which widely exist in hair, horns, claws and human skin. There is a great interest in developing keratinase to manage keratin waste generated by the poultry industry and reusing keratin products in agriculture, medical treatment and feed industries. Degradation of keratin waste by keratinase is more environmentally friendly and more sustainable compared with chemical and physical methods. However, the wild-type keratinase-producing strains usually cannot meet the requirements of industrial production, and some are pathogenic, limiting their development and utilization. The main purpose of this study is to improve the catalytic performance of keratinase via directed evolution technology for the degradation of feathers. We first constructed a mutant library through error-prone PCR and screened variants with enhanced enzyme activity. The keratinase activity was further improved through fermentation conditions optimization and fed-batch strategies in a 7-L bioreactor. As a result, nine mutants with enhanced activity were identified and the highest enzyme activity was improved from 1150 to 8448 U/mL finally. The mutant achieved efficient biodegradation of feathers, increasing the degradation rate from 49 to 88%. Moreover, a large number of amino acids and soluble peptides were obtained as degradation products, which were excellent protein resources to feed. Therefore, the study provided a keratinase mutant with application potential in the management of feather waste and preparation of protein feed additive.
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Affiliation(s)
- Jing Zhang
- Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, School of Life Sciences and Health Engineering, Jiangnan University, Lihu Avenue No. 1800, Wuxi, 214122, People's Republic of China
- National Engineering Research Center for Cereal Fermentation and Food Biomanufacturing, School of Biotechnology, Jiangnan University, Wuxi, 214122, People's Republic of China
- Jiangsu Provincial Engineering Research Center for Bioactive Product Processing, Jiangnan University, Wuxi, 214122, People's Republic of China
| | - Chang Su
- Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, School of Life Sciences and Health Engineering, Jiangnan University, Lihu Avenue No. 1800, Wuxi, 214122, People's Republic of China
| | - Xiao-Li Kong
- Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, School of Life Sciences and Health Engineering, Jiangnan University, Lihu Avenue No. 1800, Wuxi, 214122, People's Republic of China
| | - Jin-Song Gong
- Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, School of Life Sciences and Health Engineering, Jiangnan University, Lihu Avenue No. 1800, Wuxi, 214122, People's Republic of China.
| | - Yan-Lin Liu
- Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, School of Life Sciences and Health Engineering, Jiangnan University, Lihu Avenue No. 1800, Wuxi, 214122, People's Republic of China
| | - Heng Li
- Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, School of Life Sciences and Health Engineering, Jiangnan University, Lihu Avenue No. 1800, Wuxi, 214122, People's Republic of China
| | - Jiufu Qin
- Science Center for Future Foods, Jiangnan University, Wuxi, 214122, People's Republic of China
| | - Zheng-Hong Xu
- National Engineering Research Center for Cereal Fermentation and Food Biomanufacturing, School of Biotechnology, Jiangnan University, Wuxi, 214122, People's Republic of China
- Jiangsu Provincial Engineering Research Center for Bioactive Product Processing, Jiangnan University, Wuxi, 214122, People's Republic of China
| | - Jin-Song Shi
- Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, School of Life Sciences and Health Engineering, Jiangnan University, Lihu Avenue No. 1800, Wuxi, 214122, People's Republic of China.
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26
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Schafer JW, Chen X, Schwartz SD. Engineered Tryptophan Synthase Balances Equilibrium Effects and Fast Dynamic Effects. ACS Catal 2022; 12:913-922. [PMID: 35719741 PMCID: PMC9202816 DOI: 10.1021/acscatal.1c03913] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
Creating efficient and stable enzymes for catalysis in pharmaceutical and industrial laboratories is an important research goal. Arnold et al. used directed evolution to engineer a natural tryptophan synthase to create a mutant that is operable under laboratory conditions without the need for a natural allosteric effector. The use of directed evolution allows researchers to improve enzymes without understanding the structure-activity relationship. Here, we present a transition path sampling study of a key chemical transformation in the tryptophan synthase catalytic cycle. We observed that while directed evolution does mimic the natural allosteric effect from a stability perspective, fast protein dynamics associated with chemistry has been dramatically altered. This work provides further evidence of the role of protein dynamics in catalysis and clearly demonstrates the multifaceted complexity of mutations associated with protein engineering. This study also demonstrates a fascinating contrast between allosteric and stand-alone functions at the femtosecond time scale.
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Affiliation(s)
- Joseph W Schafer
- Department of Computational Medicine and Bioinformatics, University of Michigan, Ann Arbor, Michigan 48109, United States
| | - Xi Chen
- Department of Chemistry and Biochemistry, The University of Arizona, Tucson, Arizona 85721, United States
| | - Steven D Schwartz
- Department of Computational Medicine and Bioinformatics, University of Michigan, Ann Arbor, Michigan 48109, United States
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27
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Holmes JB, Liu V, Caulkins BG, Hilario E, Ghosh RK, Drago VN, Young RP, Romero JA, Gill AD, Bogie PM, Paulino J, Wang X, Riviere G, Bosken YK, Struppe J, Hassan A, Guidoulianov J, Perrone B, Mentink-Vigier F, Chang CEA, Long JR, Hooley RJ, Mueser TC, Dunn MF, Mueller LJ. Imaging active site chemistry and protonation states: NMR crystallography of the tryptophan synthase α-aminoacrylate intermediate. Proc Natl Acad Sci U S A 2022; 119:e2109235119. [PMID: 34996869 PMCID: PMC8764694 DOI: 10.1073/pnas.2109235119] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/15/2021] [Indexed: 02/07/2023] Open
Abstract
NMR-assisted crystallography-the integrated application of solid-state NMR, X-ray crystallography, and first-principles computational chemistry-holds significant promise for mechanistic enzymology: by providing atomic-resolution characterization of stable intermediates in enzyme active sites, including hydrogen atom locations and tautomeric equilibria, NMR crystallography offers insight into both structure and chemical dynamics. Here, this integrated approach is used to characterize the tryptophan synthase α-aminoacrylate intermediate, a defining species for pyridoxal-5'-phosphate-dependent enzymes that catalyze β-elimination and replacement reactions. For this intermediate, NMR-assisted crystallography is able to identify the protonation states of the ionizable sites on the cofactor, substrate, and catalytic side chains as well as the location and orientation of crystallographic waters within the active site. Most notable is the water molecule immediately adjacent to the substrate β-carbon, which serves as a hydrogen bond donor to the ε-amino group of the acid-base catalytic residue βLys87. From this analysis, a detailed three-dimensional picture of structure and reactivity emerges, highlighting the fate of the L-serine hydroxyl leaving group and the reaction pathway back to the preceding transition state. Reaction of the α-aminoacrylate intermediate with benzimidazole, an isostere of the natural substrate indole, shows benzimidazole bound in the active site and poised for, but unable to initiate, the subsequent bond formation step. When modeled into the benzimidazole position, indole is positioned with C3 in contact with the α-aminoacrylate Cβ and aligned for nucleophilic attack. Here, the chemically detailed, three-dimensional structure from NMR-assisted crystallography is key to understanding why benzimidazole does not react, while indole does.
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Affiliation(s)
- Jacob B Holmes
- Department of Chemistry, University of California, Riverside, CA 92521
| | - Viktoriia Liu
- Department of Chemistry, University of California, Riverside, CA 92521
| | - Bethany G Caulkins
- Department of Chemistry, University of California, Riverside, CA 92521
- W.M. Keck Science Department, Claremont McKenna, Pitzer, and Scripps Colleges, Claremont, CA 91711
| | - Eduardo Hilario
- Department of Chemistry, University of California, Riverside, CA 92521
| | - Rittik K Ghosh
- Department of Biochemistry, University of California, Riverside, CA 92521
| | - Victoria N Drago
- Department of Chemistry and Biochemistry, University of Toledo, Toledo, OH 43606
| | - Robert P Young
- Environmental Molecular Sciences Laboratory, Pacific Northwest National Laboratory, Richland, WA 99354
| | - Jennifer A Romero
- Department of Chemistry, University of California, Riverside, CA 92521
| | - Adam D Gill
- Department of Biochemistry, University of California, Riverside, CA 92521
| | - Paul M Bogie
- Department of Chemistry, University of California, Riverside, CA 92521
| | - Joana Paulino
- National High Magnetic Field Laboratory, Florida State University, Tallahassee, FL 32310
| | - Xiaoling Wang
- National High Magnetic Field Laboratory, Florida State University, Tallahassee, FL 32310
| | - Gwladys Riviere
- Department of Biochemistry and Molecular Biology, McKnight Brain Institute, National High Magnetic Field Laboratory, University of Florida, Gainesville, FL 32610
| | - Yuliana K Bosken
- Department of Biochemistry, University of California, Riverside, CA 92521
| | | | - Alia Hassan
- Bruker Switzerland AG 8117 Fällanden, Switzerland
| | | | | | | | - Chia-En A Chang
- Department of Chemistry, University of California, Riverside, CA 92521
| | - Joanna R Long
- Department of Biochemistry and Molecular Biology, McKnight Brain Institute, National High Magnetic Field Laboratory, University of Florida, Gainesville, FL 32610
| | - Richard J Hooley
- Department of Chemistry, University of California, Riverside, CA 92521
- Department of Biochemistry, University of California, Riverside, CA 92521
| | - Timothy C Mueser
- Department of Chemistry and Biochemistry, University of Toledo, Toledo, OH 43606
| | - Michael F Dunn
- Department of Biochemistry, University of California, Riverside, CA 92521;
| | - Leonard J Mueller
- Department of Chemistry, University of California, Riverside, CA 92521;
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28
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Ospina F, Schülke KH, Hammer SC. Biocatalytic Alkylation Chemistry: Building Molecular Complexity with High Selectivity. Chempluschem 2021; 87:e202100454. [PMID: 34821073 DOI: 10.1002/cplu.202100454] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2021] [Revised: 11/05/2021] [Indexed: 12/28/2022]
Abstract
Biocatalysis has traditionally been viewed as a field that primarily enables access to chiral centers. This includes the synthesis of chiral alcohols, amines and carbonyl compounds, often through functional group interconversion via hydrolytic or oxidation-reduction reactions. This limitation is partly being overcome by the design and evolution of new enzymes. Here, we provide an overview of a recently thriving research field that we summarize as biocatalytic alkylation chemistry. In the past 3-4 years, numerous new enzymes have been developed that catalyze sp3 C-C/N/O/S bond formations. These enzymes utilize different mechanisms to generate molecular complexity by coupling simple fragments with high activity and selectivity. In many cases, the engineered enzymes perform reactions that are difficult or impossible to achieve with current small-molecule catalysts such as organocatalysts and transition-metal complexes. This review further highlights that the design of new enzyme function is particularly successful when off-the-shelf synthetic reagents are utilized to access non-natural reactive intermediates. This underscores how biocatalysis is gradually moving to a field that build molecules through selective bond forming reactions.
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Affiliation(s)
- Felipe Ospina
- Faculty of Chemistry, Bielefeld University, Universitätsstraße 25, 33615, Bielefeld, Germany
| | - Kai H Schülke
- Faculty of Chemistry, Bielefeld University, Universitätsstraße 25, 33615, Bielefeld, Germany
| | - Stephan C Hammer
- Faculty of Chemistry, Bielefeld University, Universitätsstraße 25, 33615, Bielefeld, Germany
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29
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Maria-Solano MA, Kinateder T, Iglesias-Fernández J, Sterner R, Osuna S. In Silico Identification and Experimental Validation of Distal Activity-Enhancing Mutations in Tryptophan Synthase. ACS Catal 2021; 11:13733-13743. [PMID: 34777912 PMCID: PMC8576815 DOI: 10.1021/acscatal.1c03950] [Citation(s) in RCA: 28] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2021] [Revised: 10/12/2021] [Indexed: 12/26/2022]
Abstract
Allostery is a central mechanism for the regulation of multi-enzyme complexes. The mechanistic basis that drives allosteric regulation is poorly understood but harbors key information for enzyme engineering. In the present study, we focus on the tryptophan synthase complex that is composed of TrpA and TrpB subunits, which allosterically activate each other. Specifically, we develop a rational approach for identifying key amino acid residues of TrpB distal from the active site. Those residues are predicted to be crucial for shifting the inefficient conformational ensemble of the isolated TrpB to a productive ensemble through intra-subunit allosteric effects. The experimental validation of the conformationally driven TrpB design demonstrates its superior stand-alone activity in the absence of TrpA, comparable to those enhancements obtained after multiple rounds of experimental laboratory evolution. Our work evidences that the current challenge of distal active site prediction for enhanced function in computational enzyme design has become within reach.
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Affiliation(s)
- Miguel A. Maria-Solano
- CompBioLab Group, Institut de Química Computacional i Catàlisi (IQCC) and Departament de Química, Universitat de Girona, Maria Aurèlia Capmany 69, Girona 17003, Spain
- Global AI Drug Discovery Center, College of Pharmacy and Graduate School of Pharmaceutical Science, Ewha Womans University, Seoul 03760, Republic of Korea
| | - Thomas Kinateder
- Institute of Biophysics and Physical Biochemistry, Regensburg Center for Biochemistry, University of Regensburg, Universitätsstrasse 31, Regensburg 93053, Germany
| | - Javier Iglesias-Fernández
- CompBioLab Group, Institut de Química Computacional i Catàlisi (IQCC) and Departament de Química, Universitat de Girona, Maria Aurèlia Capmany 69, Girona 17003, Spain
- Nostrum Biodiscovery, Carrer de Baldiri Reixac, 10-12, Barcelona 08028, Spain
| | - Reinhard Sterner
- Institute of Biophysics and Physical Biochemistry, Regensburg Center for Biochemistry, University of Regensburg, Universitätsstrasse 31, Regensburg 93053, Germany
| | - Sílvia Osuna
- CompBioLab Group, Institut de Química Computacional i Catàlisi (IQCC) and Departament de Química, Universitat de Girona, Maria Aurèlia Capmany 69, Girona 17003, Spain
- ICREA, Pg. Lluís Companys 23, Barcelona 08010, Spain
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30
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Xu L, Li T, Huo Z, Chen Q, Xia Q, Jiang B. Directed Evolution Improves the Enzymatic Synthesis of L-5-Hydroxytryptophan by an Engineered Tryptophan Synthase. Appl Biochem Biotechnol 2021; 193:3407-3417. [PMID: 34097254 DOI: 10.1007/s12010-021-03589-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2020] [Accepted: 05/28/2021] [Indexed: 12/01/2022]
Abstract
L-5-Hydroxytryptophan is an important amino acid that is widely used in food and medicine. In this study, L-5-hydroxytryptophan was synthesized by a modified tryptophan synthase. A direct evolution strategy was applied to engineer tryptophan synthase from Escherichia coli to improve the efficiency of L-5-hydroxytryptophan synthesis. Tryptophan synthase was modified by error-prone PCR. A high-activity mutant enzyme (V231A/K382G) was obtained by a high-throughput screening method. The activity of mutant enzyme (V231A/K382G) is 3.79 times higher than that of its parent, and kcat/Km of the mutant enzyme (V231A/K382G) is 4.36 mM-1∙s-1. The mutant enzyme (V231A/K382G) reaction conditions for the production of L-5-hydroxytryptophan were 100 mmol/L L-serine at pH 8.5 and 35°C for 15 h, reaching a yield of L-5-hydroxytryptophan of 86.7%. Directed evolution is an effective strategy to increase the activity of tryptophan synthase.
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Affiliation(s)
- Lisheng Xu
- School of Biological and Food Engineering, Suzhou University, Suzhou, 234000, China.
| | - Tingting Li
- School of Biological and Food Engineering, Suzhou University, Suzhou, 234000, China
| | - Ziyue Huo
- School of Biological and Food Engineering, Suzhou University, Suzhou, 234000, China
| | - Qiong Chen
- School of Biological and Food Engineering, Suzhou University, Suzhou, 234000, China
| | - Qiuxia Xia
- School of Biological and Food Engineering, Suzhou University, Suzhou, 234000, China
| | - Bianling Jiang
- School of Biological and Food Engineering, Suzhou University, Suzhou, 234000, China
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31
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Kapale SS, Chaudhari HK, Mali SN, Takale BS, Pawar H. A sustainable approach towards the three-component synthesis of unsubstituted 1 H-imidazoles in the water at ambient conditions. JOURNAL OF ASIAN NATURAL PRODUCTS RESEARCH 2021; 23:712-716. [PMID: 32400182 DOI: 10.1080/10286020.2020.1760852] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/15/2020] [Revised: 04/21/2020] [Accepted: 04/22/2020] [Indexed: 06/11/2023]
Abstract
A green protocol for the synthesis of unsubstituted imidazoles has been demonstrated herein. The reaction is realized using commercially available lipase enzyme, porcine pancreas lipase (PPL) in water. The reaction conditions are selective and mild which helped to tolerate a wide variety of functional groups to give the desired products in good chemical yields.[Formula: see text].
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Affiliation(s)
- Suraj S Kapale
- Department of Pharmaceutical Sciences and Technology, Institute of Chemical Technology, Nathalal Parekh Marg, Matunga (E), Mumbai 400019, India
| | - Hemchandra K Chaudhari
- Department of Pharmaceutical Sciences and Technology, Institute of Chemical Technology, Nathalal Parekh Marg, Matunga (E), Mumbai 400019, India
| | - Suraj N Mali
- Department of Pharmaceutical Sciences and Technology, Institute of Chemical Technology, Nathalal Parekh Marg, Matunga (E), Mumbai 400019, India
| | - Balaram S Takale
- Department of Chemistry and Biochemistry, University of California, Santa Barbara, CA 93106, USA
| | - Hitesh Pawar
- Centre of Biosciences, Institute of Chemical Technology, Matunga (E), Mumbai 400019, India
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32
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D'Amico RN, Bosken YK, O'Rourke KF, Murray AM, Admasu W, Chang CEA, Boehr DD. Substitution of a Surface-Exposed Residue Involved in an Allosteric Network Enhances Tryptophan Synthase Function in Cells. Front Mol Biosci 2021; 8:679915. [PMID: 34124159 PMCID: PMC8187860 DOI: 10.3389/fmolb.2021.679915] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2021] [Accepted: 05/11/2021] [Indexed: 11/13/2022] Open
Abstract
Networks of noncovalent amino acid interactions propagate allosteric signals throughout proteins. Tryptophan synthase (TS) is an allosterically controlled bienzyme in which the indole product of the alpha subunit (αTS) is transferred through a 25 Å hydrophobic tunnel to the active site of the beta subunit (βTS). Previous nuclear magnetic resonance and molecular dynamics simulations identified allosteric networks in αTS important for its function. We show here that substitution of a distant, surface-exposed network residue in αTS enhances tryptophan production, not by activating αTS function, but through dynamically controlling the opening of the indole channel and stimulating βTS activity. While stimulation is modest, the substitution also enhances cell growth in a tryptophan-auxotrophic strain of Escherichia coli compared to complementation with wild-type αTS, emphasizing the biological importance of the network. Surface-exposed networks provide new opportunities in allosteric drug design and protein engineering, and hint at potential information conduits through which the functions of a metabolon or even larger proteome might be coordinated and regulated.
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Affiliation(s)
- Rebecca N D'Amico
- Department of Chemistry, The Pennsylvania State University, University Park, PA, United States
| | - Yuliana K Bosken
- Department of Chemistry, The University of California Riverside, Riverside, CA, United States
| | - Kathleen F O'Rourke
- Department of Chemistry, The Pennsylvania State University, University Park, PA, United States
| | - Alec M Murray
- Department of Chemistry, The Pennsylvania State University, University Park, PA, United States
| | - Woudasie Admasu
- Department of Chemistry, The Pennsylvania State University, University Park, PA, United States
| | - Chia-En A Chang
- Department of Chemistry, The University of California Riverside, Riverside, CA, United States
| | - David D Boehr
- Department of Chemistry, The Pennsylvania State University, University Park, PA, United States
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33
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van den Noort M, de Boer M, Poolman B. Stability of Ligand-induced Protein Conformation Influences Affinity in Maltose-binding Protein. J Mol Biol 2021; 433:167036. [PMID: 33957147 DOI: 10.1016/j.jmb.2021.167036] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2021] [Revised: 04/13/2021] [Accepted: 04/27/2021] [Indexed: 11/18/2022]
Abstract
Our understanding of what determines ligand affinity of proteins is poor, even with high-resolution structures available. Both the non-covalent ligand-protein interactions and the relative free energies of available conformations contribute to the affinity of a protein for a ligand. Distant, non-binding site residues can influence the ligand affinity by altering the free energy difference between a ligand-free and ligand-bound conformation. Our hypothesis is that when different ligands induce distinct ligand-bound conformations, it should be possible to tweak their affinities by changing the free energies of the available conformations. We tested this idea for the maltose-binding protein (MBP) from Escherichia coli. We used single-molecule Förster resonance energy transfer (smFRET) to distinguish several unique ligand-bound conformations of MBP. We engineered mutations, distant from the binding site, to affect the stabilities of different ligand-bound conformations. We show that ligand affinity can indeed be altered in a conformation-dependent manner. Our studies provide a framework for the tuning of ligand affinity, apart from modifying binding site residues.
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Affiliation(s)
- Marco van den Noort
- Department of Biochemistry, Groningen Biomolecular Science and Biotechnology Institute, University of Groningen, Nijenborgh 4, Groningen 9747 AG, the Netherlands
| | - Marijn de Boer
- Department of Biochemistry, Groningen Biomolecular Science and Biotechnology Institute, University of Groningen, Nijenborgh 4, Groningen 9747 AG, the Netherlands
| | - Bert Poolman
- Department of Biochemistry, Groningen Biomolecular Science and Biotechnology Institute, University of Groningen, Nijenborgh 4, Groningen 9747 AG, the Netherlands.
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34
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Tee WV, Tan ZW, Lee K, Guarnera E, Berezovsky IN. Exploring the Allosteric Territory of Protein Function. J Phys Chem B 2021; 125:3763-3780. [PMID: 33844527 DOI: 10.1021/acs.jpcb.1c00540] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
While the pervasiveness of allostery in proteins is commonly accepted, we further show the generic nature of allosteric mechanisms by analyzing here transmembrane ion-channel viroporin 3a and RNA-dependent RNA polymerase (RdRp) from SARS-CoV-2 along with metabolic enzymes isocitrate dehydrogenase 1 (IDH1) and fumarate hydratase (FH) implicated in cancers. Using the previously developed structure-based statistical mechanical model of allostery (SBSMMA), we share our experience in analyzing the allosteric signaling, predicting latent allosteric sites, inducing and tuning targeted allosteric response, and exploring the allosteric effects of mutations. This, yet incomplete list of phenomenology, forms a complex and unique allosteric territory of protein function, which should be thoroughly explored. We propose a generic computational framework, which not only allows one to obtain a comprehensive allosteric control over proteins but also provides an opportunity to approach the fragment-based design of allosteric effectors and drug candidates. The advantages of allosteric drugs over traditional orthosteric compounds, complemented by the emerging role of the allosteric effects of mutations in the expansion of the cancer mutational landscape and in the increased mutability of viral proteins, leave no choice besides further extensive studies of allosteric mechanisms and their biomedical implications.
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Affiliation(s)
- Wei-Ven Tee
- Bioinformatics Institute (BII), Agency for Science, Technology and Research (A*STAR), 30 Biopolis Street, #07-01, Matrix, 138671, Singapore.,Department of Biological Sciences (DBS), National University of Singapore (NUS), 8 Medical Drive, 117597, Singapore
| | - Zhen Wah Tan
- Bioinformatics Institute (BII), Agency for Science, Technology and Research (A*STAR), 30 Biopolis Street, #07-01, Matrix, 138671, Singapore
| | - Keene Lee
- Bioinformatics Institute (BII), Agency for Science, Technology and Research (A*STAR), 30 Biopolis Street, #07-01, Matrix, 138671, Singapore
| | - Enrico Guarnera
- Bioinformatics Institute (BII), Agency for Science, Technology and Research (A*STAR), 30 Biopolis Street, #07-01, Matrix, 138671, Singapore
| | - Igor N Berezovsky
- Bioinformatics Institute (BII), Agency for Science, Technology and Research (A*STAR), 30 Biopolis Street, #07-01, Matrix, 138671, Singapore.,Department of Biological Sciences (DBS), National University of Singapore (NUS), 8 Medical Drive, 117597, Singapore
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35
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Damry AM, Jackson CJ. The evolution and engineering of enzyme activity through tuning conformational landscapes. Protein Eng Des Sel 2021; 34:6254467. [PMID: 33903911 DOI: 10.1093/protein/gzab009] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2021] [Revised: 03/22/2021] [Accepted: 03/23/2021] [Indexed: 11/12/2022] Open
Abstract
Proteins are dynamic molecules whose structures consist of an ensemble of conformational states. Dynamics contribute to protein function and a link to protein evolution has begun to emerge. This increased appreciation for the evolutionary impact of conformational sampling has grown from our developing structural biology capabilities and the exploration of directed evolution approaches, which have allowed evolutionary trajectories to be mapped. Recent studies have provided empirical examples of how proteins can evolve via conformational landscape alterations. Moreover, minor conformational substates have been shown to be involved in the emergence of new enzyme functions as they can become enriched through evolution. The role of remote mutations in stabilizing new active site geometries has also granted insight into the molecular basis underpinning poorly understood epistatic effects that guide protein evolution. Finally, we discuss how the growth of our understanding of remote mutations is beginning to refine our approach to engineering enzymes.
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Affiliation(s)
- Adam M Damry
- Research School of Chemistry, The Australian National University, Canberra, 2601, Australia
| | - Colin J Jackson
- Research School of Chemistry, The Australian National University, Canberra, 2601, Australia.,Australian Research Council Centre of Excellence for Innovations in Peptide and Protein Science, Research School of Chemistry, Australian National University, Canberra, 2601, ACT, Australia.,Australian Research Council Centre of Excellence in Synthetic Biology, Research School of Chemistry, Australian National University, Canberra, 2601, ACT, Australia
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36
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Computational investigations of allostery in aromatic amino acid biosynthetic enzymes. Biochem Soc Trans 2021; 49:415-429. [PMID: 33544132 DOI: 10.1042/bst20200741] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2020] [Revised: 01/14/2021] [Accepted: 01/15/2021] [Indexed: 12/22/2022]
Abstract
Allostery, in which binding of ligands to remote sites causes a functional change in the active sites, is a fascinating phenomenon observed in enzymes. Allostery can occur either with or without significant conformational changes in the enzymes, and the molecular basis of its mechanism can be difficult to decipher using only experimental techniques. Computational tools for analyzing enzyme sequences, structures, and dynamics can provide insights into the allosteric mechanism at the atomic level. Combining computational and experimental methods offers a powerful strategy for the study of enzyme allostery. The aromatic amino acid biosynthesis pathway is essential in microorganisms and plants. Multiple enzymes involved in this pathway are sensitive to feedback regulation by pathway end products and are known to use allostery to control their activities. To date, four enzymes in the aromatic amino acid biosynthesis pathway have been computationally investigated for their allosteric mechanisms, including 3-deoxy-d-arabino-heptulosonate 7-phosphate synthase, anthranilate synthase, chorismate mutase, and tryptophan synthase. Here we review the computational studies and findings on the allosteric mechanisms of these four enzymes. Results from these studies demonstrate the capability of computational tools and encourage future computational investigations of allostery in other enzymes of this pathway.
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37
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Simeth NA, Kinateder T, Rajendran C, Nazet J, Merkl R, Sterner R, König B, Kneuttinger AC. Towards Photochromic Azobenzene-Based Inhibitors for Tryptophan Synthase. Chemistry 2021; 27:2439-2451. [PMID: 33078454 PMCID: PMC7898615 DOI: 10.1002/chem.202004061] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2020] [Revised: 10/16/2020] [Indexed: 01/25/2023]
Abstract
Light regulation of drug molecules has gained growing interest in biochemical and pharmacological research in recent years. In addition, a serious need for novel molecular targets of antibiotics has emerged presently. Herein, the development of a photocontrollable, azobenzene-based antibiotic precursor towards tryptophan synthase (TS), an essential metabolic multienzyme complex in bacteria, is presented. The compound exhibited moderately strong inhibition of TS in its E configuration and five times lower inhibition strength in its Z configuration. A combination of biochemical, crystallographic, and computational analyses was used to characterize the inhibition mode of this compound. Remarkably, binding of the inhibitor to a hitherto-unconsidered cavity results in an unproductive conformation of TS leading to noncompetitive inhibition of tryptophan production. In conclusion, we created a promising lead compound for combatting bacterial diseases, which targets an essential metabolic enzyme, and whose inhibition strength can be controlled with light.
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Affiliation(s)
- Nadja A. Simeth
- Institute for Organic ChemistryDepartment of Chemistry and PharmacyUniversity of RegensburgUniversitätsstrasse 3193040RegensburgGermany
- Stratingh Institute for ChemistryFaculty of Science and EngineeringUniversity of GroningenNijenborgh 49747AGGroningenThe Netherlands
| | - Thomas Kinateder
- Institute for Biophysics and Physical BiochemistryRegensburg Center for BiochemistryUniversity of RegensburgUniversitätsstrasse 3193040RegensburgGermany
| | - Chitra Rajendran
- Institute for Biophysics and Physical BiochemistryRegensburg Center for BiochemistryUniversity of RegensburgUniversitätsstrasse 3193040RegensburgGermany
| | - Julian Nazet
- Institute for Biophysics and Physical BiochemistryRegensburg Center for BiochemistryUniversity of RegensburgUniversitätsstrasse 3193040RegensburgGermany
| | - Rainer Merkl
- Institute for Biophysics and Physical BiochemistryRegensburg Center for BiochemistryUniversity of RegensburgUniversitätsstrasse 3193040RegensburgGermany
| | - Reinhard Sterner
- Institute for Biophysics and Physical BiochemistryRegensburg Center for BiochemistryUniversity of RegensburgUniversitätsstrasse 3193040RegensburgGermany
| | - Burkhard König
- Institute for Organic ChemistryDepartment of Chemistry and PharmacyUniversity of RegensburgUniversitätsstrasse 3193040RegensburgGermany
| | - Andrea C. Kneuttinger
- Institute for Biophysics and Physical BiochemistryRegensburg Center for BiochemistryUniversity of RegensburgUniversitätsstrasse 3193040RegensburgGermany
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38
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Abstract
QM/MM simulations have become an indispensable tool in many chemical and biochemical investigations. Considering the tremendous degree of success, including recognition by a 2013 Nobel Prize in Chemistry, are there still "burning challenges" in QM/MM methods, especially for biomolecular systems? In this short Perspective, we discuss several issues that we believe greatly impact the robustness and quantitative applicability of QM/MM simulations to many, if not all, biomolecules. We highlight these issues with observations and relevant advances from recent studies in our group and others in the field. Despite such limited scope, we hope the discussions are of general interest and will stimulate additional developments that help push the field forward in meaningful directions.
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Affiliation(s)
- Qiang Cui
- Departments of Chemistry, Physics, and Biomedical Engineering, Boston University, 590 Commonwealth Avenue, Boston, Massachusetts 02215, United States
| | - Tanmoy Pal
- Department of Chemistry, Boston University, 590 Commonwealth Avenue, Boston, Massachusetts 02215, United States
| | - Luke Xie
- Department of Chemistry, Boston University, 590 Commonwealth Avenue, Boston, Massachusetts 02215, United States
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39
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Kumar P, Meza A, Ellis JM, Carlson GA, Bingman CA, Buller AR. l-Threonine Transaldolase Activity Is Enabled by a Persistent Catalytic Intermediate. ACS Chem Biol 2021; 16:86-95. [PMID: 33337128 DOI: 10.1021/acschembio.0c00753] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
l-Threonine transaldolases (lTTAs) are a poorly characterized class of pyridoxal-5'-phosphate (PLP) dependent enzymes responsible for the biosynthesis of diverse β-hydroxy amino acids. Here, we study the catalytic mechanism of ObiH, an lTTA essential for biosynthesis of the β-lactone natural product obafluorin. Heterologously expressed ObiH purifies as a mixture of chemical states including a catalytically inactive form of the PLP cofactor. Photoexcitation of ObiH promotes the conversion of the inactive state of the enzyme to the active form. UV-vis spectroscopic analysis reveals that ObiH catalyzes the retro-aldol cleavage of l-threonine to form a remarkably persistent glycyl quinonoid intermediate, with a half-life of ∼3 h. Protonation of this intermediate is kinetically disfavored, enabling on-cycle reactivity with aldehydes to form β-hydroxy amino acids. We demonstrate the synthetic potential of ObiH via the single step synthesis of (2S,3R)-β-hydroxyleucine. To further understand the structural features underpinning this desirable reactivity, we determined the crystal structure of ObiH bound to PLP as the Schiff's base at 1.66 Å resolution. This high-resolution model revealed a unique active site configuration wherein the evolutionarily conserved Asp that traditionally H-bonds to the cofactor is swapped for a neighboring Glu. Molecular dynamics simulations combined with mutagenesis studies indicate that a structural rearrangement is associated with l-threonine entry into the catalytic cycle. Together, these data explain the basis for the unique reactivity of lTTA enzymes and provide a foundation for future engineering and mechanistic analysis.
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Affiliation(s)
- Prasanth Kumar
- Department of Chemistry, University of Wisconsin—Madison, 1101 University Avenue, Madison, Wisconsin 53706, United States
| | - Anthony Meza
- Department of Biochemistry, University of Wisconsin—Madison, 1101 University Avenue, Madison, Wisconsin 53706, United States
| | - Jonathan M. Ellis
- Department of Chemistry, University of Wisconsin—Madison, 1101 University Avenue, Madison, Wisconsin 53706, United States
| | - Grace A. Carlson
- Department of Chemistry, University of Wisconsin—Madison, 1101 University Avenue, Madison, Wisconsin 53706, United States
| | - Craig A. Bingman
- Department of Biochemistry, University of Wisconsin—Madison, 1101 University Avenue, Madison, Wisconsin 53706, United States
| | - Andrew R. Buller
- Department of Chemistry, University of Wisconsin—Madison, 1101 University Avenue, Madison, Wisconsin 53706, United States
- Department of Biochemistry, University of Wisconsin—Madison, 1101 University Avenue, Madison, Wisconsin 53706, United States
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40
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Watkins-Dulaney E, Straathof S, Arnold F. Tryptophan Synthase: Biocatalyst Extraordinaire. Chembiochem 2021; 22:5-16. [PMID: 32677310 PMCID: PMC7935429 DOI: 10.1002/cbic.202000379] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2020] [Revised: 07/15/2020] [Indexed: 12/23/2022]
Abstract
Tryptophan synthase (TrpS) has emerged as a paragon of noncanonical amino acid (ncAA) synthesis and is an ideal biocatalyst for synthetic and biological applications. TrpS catalyzes an irreversible, C-C bond-forming reaction between indole and serine to make l-tryptophan; native TrpS complexes possess fairly broad specificity for indole analogues, but are difficult to engineer to extend substrate scope or to confer other useful properties due to allosteric constraints and their heterodimeric structure. Directed evolution freed the catalytically relevant TrpS β-subunit (TrpB) from allosteric regulation by its TrpA partner and has enabled dramatic expansion of the enzyme's substrate scope. This review examines the long and storied career of TrpS from the perspective of its application in ncAA synthesis and biocatalytic cascades.
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Affiliation(s)
- Ella Watkins-Dulaney
- Division of Biology and Biological Engineering, California Institute of Technology, MC 210-41, 1200 E. California Boulevard, Pasadena, CA 91125, USA
| | - Sabine Straathof
- Division of Chemistry and Chemical Engineering, California Institute of Technology, MC 210-41, 1200 E. California Boulevard, Pasadena, CA 91125, USA
| | - Frances Arnold
- Division of Biology and Biological Engineering, California Institute of Technology, MC 210-41, 1200 E. California Boulevard, Pasadena, CA 91125, USA
- Division of Chemistry and Chemical Engineering, California Institute of Technology, MC 210-41, 1200 E. California Boulevard, Pasadena, CA 91125, USA
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41
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Rix G, Watkins-Dulaney EJ, Almhjell PJ, Boville CE, Arnold FH, Liu CC. Scalable continuous evolution for the generation of diverse enzyme variants encompassing promiscuous activities. Nat Commun 2020; 11:5644. [PMID: 33159067 PMCID: PMC7648111 DOI: 10.1038/s41467-020-19539-6] [Citation(s) in RCA: 44] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2020] [Accepted: 10/19/2020] [Indexed: 01/11/2023] Open
Abstract
Enzyme orthologs sharing identical primary functions can have different promiscuous activities. While it is possible to mine this natural diversity to obtain useful biocatalysts, generating comparably rich ortholog diversity is difficult, as it is the product of deep evolutionary processes occurring in a multitude of separate species and populations. Here, we take a first step in recapitulating the depth and scale of natural ortholog evolution on laboratory timescales. Using a continuous directed evolution platform called OrthoRep, we rapidly evolve the Thermotoga maritima tryptophan synthase β-subunit (TmTrpB) through multi-mutation pathways in many independent replicates, selecting only on TmTrpB's primary activity of synthesizing L-tryptophan from indole and L-serine. We find that the resulting sequence-diverse TmTrpB variants span a range of substrate profiles useful in industrial biocatalysis and suggest that the depth and scale of evolution that OrthoRep affords will be generally valuable in enzyme engineering and the evolution of biomolecular functions.
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Affiliation(s)
- Gordon Rix
- Department of Molecular Biology and Biochemistry, University of California, Irvine, CA, USA
| | - Ella J Watkins-Dulaney
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA, USA
| | - Patrick J Almhjell
- Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, CA, USA
| | - Christina E Boville
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA, USA
- Aralez Bio, Emeryville, CA, USA
| | - Frances H Arnold
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA, USA
- Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, CA, USA
| | - Chang C Liu
- Department of Molecular Biology and Biochemistry, University of California, Irvine, CA, USA.
- Department of Biomedical Engineering, University of California, Irvine, CA, USA.
- Department of Chemistry, University of California, Irvine, CA, USA.
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42
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Crean RM, Gardner JM, Kamerlin SCL. Harnessing Conformational Plasticity to Generate Designer Enzymes. J Am Chem Soc 2020; 142:11324-11342. [PMID: 32496764 PMCID: PMC7467679 DOI: 10.1021/jacs.0c04924] [Citation(s) in RCA: 65] [Impact Index Per Article: 16.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2020] [Indexed: 02/08/2023]
Abstract
Recent years have witnessed an explosion of interest in understanding the role of conformational dynamics both in the evolution of new enzymatic activities from existing enzymes and in facilitating the emergence of enzymatic activity de novo on scaffolds that were previously non-catalytic. There are also an increasing number of examples in the literature of targeted engineering of conformational dynamics being successfully used to alter enzyme selectivity and activity. Despite the obvious importance of conformational dynamics to both enzyme function and evolvability, many (although not all) computational design approaches still focus either on pure sequence-based approaches or on using structures with limited flexibility to guide the design. However, there exist a wide variety of computational approaches that can be (re)purposed to introduce conformational dynamics as a key consideration in the design process. Coupled with laboratory evolution and more conventional existing sequence- and structure-based approaches, these techniques provide powerful tools for greatly expanding the protein engineering toolkit. This Perspective provides an overview of evolutionary studies that have dissected the role of conformational dynamics in facilitating the emergence of novel enzymes, as well as advances in computational approaches that allow one to target conformational dynamics as part of enzyme design. Harnessing conformational dynamics in engineering studies is a powerful paradigm with which to engineer the next generation of designer biocatalysts.
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Affiliation(s)
- Rory M. Crean
- Department of Chemistry -
BMC, Uppsala University, Box 576, 751 23 Uppsala, Sweden
| | - Jasmine M. Gardner
- Department of Chemistry -
BMC, Uppsala University, Box 576, 751 23 Uppsala, Sweden
| | - Shina C. L. Kamerlin
- Department of Chemistry -
BMC, Uppsala University, Box 576, 751 23 Uppsala, Sweden
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43
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Thompson CM, McDonald AD, Yang H, Cavagnero S, Buller AR. Modular control of l-tryptophan isotopic substitution via an efficient biosynthetic cascade. Org Biomol Chem 2020; 18:4189-4192. [PMID: 32452506 DOI: 10.1039/d0ob00868k] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Isotopologs are powerful tools for investigating biological systems. We report a biosynthetic-cascade synthesis of Trp isotopologs starting from indole, glycine, and formaldehyde using the enzymes l-threonine aldolase and an engineered β-subunit of tryptophan synthase. This modular route to Trp isotopologs is simple and inexpensive, enabling facile access to these compounds.
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Affiliation(s)
- Clayton M Thompson
- Department of Chemistry, University of Wisconsin-Madison, 1101 University Ave, Madison, WI. 53706, USA.
| | - Allwin D McDonald
- Department of Chemistry, University of Wisconsin-Madison, 1101 University Ave, Madison, WI. 53706, USA.
| | - Hanming Yang
- Department of Chemistry, University of Wisconsin-Madison, 1101 University Ave, Madison, WI. 53706, USA.
| | - Silvia Cavagnero
- Department of Chemistry, University of Wisconsin-Madison, 1101 University Ave, Madison, WI. 53706, USA.
| | - Andrew R Buller
- Department of Chemistry, University of Wisconsin-Madison, 1101 University Ave, Madison, WI. 53706, USA.
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44
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Nödling AR, Santi N, Williams TL, Tsai YH, Luk LYP. Enabling protein-hosted organocatalytic transformations. RSC Adv 2020; 10:16147-16161. [PMID: 33184588 PMCID: PMC7654312 DOI: 10.1039/d0ra01526a] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2020] [Accepted: 03/25/2020] [Indexed: 12/30/2022] Open
Abstract
In this review, the development of organocatalytic artificial enzymes will be discussed. This area of protein engineering research has underlying importance, as it enhances the biocompatibility of organocatalysis for applications in chemical and synthetic biology research whilst expanding the catalytic repertoire of enzymes. The approaches towards the preparation of organocatalytic artificial enzymes, techniques used to improve their performance (selectivity and reactivity) as well as examples of their applications are presented. Challenges and opportunities are also discussed.
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Affiliation(s)
- Alexander R Nödling
- School of Chemistry, Cardiff University, Main Building, Cardiff, CF10 3AT, UK.
| | - Nicolò Santi
- School of Chemistry, Cardiff University, Main Building, Cardiff, CF10 3AT, UK.
| | - Thomas L Williams
- School of Chemistry, Cardiff University, Main Building, Cardiff, CF10 3AT, UK.
| | - Yu-Hsuan Tsai
- School of Chemistry, Cardiff University, Main Building, Cardiff, CF10 3AT, UK.
| | - Louis Y P Luk
- School of Chemistry, Cardiff University, Main Building, Cardiff, CF10 3AT, UK.
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45
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Lake PT, Davidson RB, Klem H, Hocky GM, McCullagh M. Residue-Level Allostery Propagates through the Effective Coarse-Grained Hessian. J Chem Theory Comput 2020; 16:3385-3395. [PMID: 32251581 DOI: 10.1021/acs.jctc.9b01149] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
The long-ranged coupling between residues that gives rise to allostery in a protein is built up from short-ranged physical interactions. Computational tools used to predict this coupling and its functional relevance have relied on the application of graph theoretical metrics to residue-level correlations measured from all-atom molecular dynamics simulations. The short-ranged interactions that yield these long-ranged residue-level correlations are quantified by the effective coarse-grained Hessian. Here we compute an effective harmonic coarse-grained Hessian from simulations of a benchmark allosteric protein, IGPS, and demonstrate the improved locality of this graph Laplacian over two other connectivity matrices. Additionally, two centrality metrics are developed that indicate the direct and indirect importance of each residue at producing the covariance between the effector binding pocket and the active site. The residue importance indicated by these two metrics is corroborated by previous mutagenesis experiments and leads to unique functional insights; in contrast to previous computational analyses, our results suggest that fP76-hK181 is the most important contact for conveying direct allosteric paths across the HisF-HisH interface. The connectivity around fD98 is found to be important at affecting allostery through indirect means.
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Affiliation(s)
- Peter T Lake
- Department of Chemistry, Colorado State University, Fort Collins, Colorado 80523, United States
| | - Russell B Davidson
- Department of Chemistry, Colorado State University, Fort Collins, Colorado 80523, United States
| | - Heidi Klem
- Department of Chemistry, Colorado State University, Fort Collins, Colorado 80523, United States
| | - Glen M Hocky
- Department of Chemistry, New York University, New York, New York 10003, United States
| | - Martin McCullagh
- Department of Chemistry, Colorado State University, Fort Collins, Colorado 80523, United States
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46
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Surpeta B, Sequeiros-Borja CE, Brezovsky J. Dynamics, a Powerful Component of Current and Future in Silico Approaches for Protein Design and Engineering. Int J Mol Sci 2020; 21:E2713. [PMID: 32295283 PMCID: PMC7215530 DOI: 10.3390/ijms21082713] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2020] [Revised: 04/10/2020] [Accepted: 04/12/2020] [Indexed: 12/13/2022] Open
Abstract
Computational prediction has become an indispensable aid in the processes of engineering and designing proteins for various biotechnological applications. With the tremendous progress in more powerful computer hardware and more efficient algorithms, some of in silico tools and methods have started to apply the more realistic description of proteins as their conformational ensembles, making protein dynamics an integral part of their prediction workflows. To help protein engineers to harness benefits of considering dynamics in their designs, we surveyed new tools developed for analyses of conformational ensembles in order to select engineering hotspots and design mutations. Next, we discussed the collective evolution towards more flexible protein design methods, including ensemble-based approaches, knowledge-assisted methods, and provable algorithms. Finally, we highlighted apparent challenges that current approaches are facing and provided our perspectives on their further development.
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Affiliation(s)
- Bartłomiej Surpeta
- Laboratory of Biomolecular Interactions and Transport, Department of Gene Expression, Institute of Molecular Biology and Biotechnology, Faculty of Biology, Adam Mickiewicz University, Uniwersytetu Poznanskiego 6, 61-614 Poznan, Poland; (B.S.); (C.E.S.-B.)
- International Institute of Molecular and Cell Biology in Warsaw, Ks Trojdena 4, 02-109 Warsaw, Poland
| | - Carlos Eduardo Sequeiros-Borja
- Laboratory of Biomolecular Interactions and Transport, Department of Gene Expression, Institute of Molecular Biology and Biotechnology, Faculty of Biology, Adam Mickiewicz University, Uniwersytetu Poznanskiego 6, 61-614 Poznan, Poland; (B.S.); (C.E.S.-B.)
- International Institute of Molecular and Cell Biology in Warsaw, Ks Trojdena 4, 02-109 Warsaw, Poland
| | - Jan Brezovsky
- Laboratory of Biomolecular Interactions and Transport, Department of Gene Expression, Institute of Molecular Biology and Biotechnology, Faculty of Biology, Adam Mickiewicz University, Uniwersytetu Poznanskiego 6, 61-614 Poznan, Poland; (B.S.); (C.E.S.-B.)
- International Institute of Molecular and Cell Biology in Warsaw, Ks Trojdena 4, 02-109 Warsaw, Poland
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47
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Analysis of allosteric communication in a multienzyme complex by ancestral sequence reconstruction. Proc Natl Acad Sci U S A 2019; 117:346-354. [PMID: 31871208 DOI: 10.1073/pnas.1912132117] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Tryptophan synthase (TS) is a heterotetrameric αββα complex. It is characterized by the channeling of the reaction intermediate indole and the mutual activation of the α-subunit TrpA and the β-subunit TrpB via a complex allosteric network. We have analyzed this allosteric network by means of ancestral sequence reconstruction (ASR), which is an in silico method to resurrect extinct ancestors of modern proteins. Previously, the sequences of TrpA and TrpB from the last bacterial common ancestor (LBCA) have been computed by means of ASR and characterized. LBCA-TS is similar to modern TS by forming a αββα complex with indole channeling taking place. However, LBCA-TrpA allosterically decreases the activity of LBCA-TrpB, whereas, for example, the modern ncTrpA from Neptuniibacter caesariensis allosterically increases the activity of ncTrpB. To identify amino acid residues that are responsible for this inversion of the allosteric effect, all 6 evolutionary TrpA and TrpB intermediates that stepwise link LBCA-TS with ncTS were characterized. Remarkably, the switching from TrpB inhibition to TrpB activation by TrpA occurred between 2 successive TS intermediates. Sequence comparison of these 2 intermediates and iterative rounds of site-directed mutagenesis allowed us to identify 4 of 413 residues from TrpB that are crucial for its allosteric activation by TrpA. The effect of our mutational studies was rationalized by a community analysis based on molecular dynamics simulations. Our findings demonstrate that ancestral sequence reconstruction can efficiently identify residues contributing to allosteric signal propagation in multienzyme complexes.
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48
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Zhang Y, Doruker P, Kaynak B, Zhang S, Krieger J, Li H, Bahar I. Intrinsic dynamics is evolutionarily optimized to enable allosteric behavior. Curr Opin Struct Biol 2019; 62:14-21. [PMID: 31785465 DOI: 10.1016/j.sbi.2019.11.002] [Citation(s) in RCA: 62] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2019] [Revised: 10/31/2019] [Accepted: 11/04/2019] [Indexed: 12/13/2022]
Abstract
Allosteric behavior is central to the function of many proteins, enabling molecular machinery, metabolism, signaling and regulation. Recent years have shown that the intrinsic dynamics of allosteric proteins defined by their 3-dimensional architecture or by the topology of inter-residue contacts favors cooperative motions that bear close similarity to structural changes they undergo during their allosteric actions. These conformational motions are usually driven by energetically favorable or soft modes at the low frequency end of the mode spectrum, and they are evolutionarily conserved among orthologs. These observations brought into light evolutionary adaptation mechanisms that help maintain, optimize or regulate allosteric behavior as the evolution from bacterial to higher organisms introduces sequential heterogeneities and structural complexities.
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Affiliation(s)
- Yan Zhang
- Department of Computational and Systems Biology, School of Medicine, University of Pittsburgh, 3501 Fifth Ave, Suite 3064 BST3, Pittsburgh, PA 15260, USA
| | - Pemra Doruker
- Department of Computational and Systems Biology, School of Medicine, University of Pittsburgh, 3501 Fifth Ave, Suite 3064 BST3, Pittsburgh, PA 15260, USA
| | - Burak Kaynak
- Department of Computational and Systems Biology, School of Medicine, University of Pittsburgh, 3501 Fifth Ave, Suite 3064 BST3, Pittsburgh, PA 15260, USA
| | - She Zhang
- Department of Computational and Systems Biology, School of Medicine, University of Pittsburgh, 3501 Fifth Ave, Suite 3064 BST3, Pittsburgh, PA 15260, USA
| | - James Krieger
- Department of Computational and Systems Biology, School of Medicine, University of Pittsburgh, 3501 Fifth Ave, Suite 3064 BST3, Pittsburgh, PA 15260, USA
| | - Hongchun Li
- Department of Computational and Systems Biology, School of Medicine, University of Pittsburgh, 3501 Fifth Ave, Suite 3064 BST3, Pittsburgh, PA 15260, USA; Research Center for Computer-Aided Drug Discovery, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen 518055, China
| | - Ivet Bahar
- Department of Computational and Systems Biology, School of Medicine, University of Pittsburgh, 3501 Fifth Ave, Suite 3064 BST3, Pittsburgh, PA 15260, USA.
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Kneuttinger AC, Zwisele S, Straub K, Bruckmann A, Busch F, Kinateder T, Gaim B, Wysocki VH, Merkl R, Sterner R. Light-Regulation of Tryptophan Synthase by Combining Protein Design and Enzymology. Int J Mol Sci 2019; 20:E5106. [PMID: 31618845 PMCID: PMC6829457 DOI: 10.3390/ijms20205106] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2019] [Revised: 10/11/2019] [Accepted: 10/12/2019] [Indexed: 01/24/2023] Open
Abstract
The spatiotemporal control of enzymes by light is of growing importance for industrial biocatalysis. Within this context, the photo-control of allosteric interactions in enzyme complexes, common to practically all metabolic pathways, is particularly relevant. A prominent example of a metabolic complex with a high application potential is tryptophan synthase from Salmonella typhimurium (TS), in which the constituting TrpA and TrpB subunits mutually stimulate each other via a sophisticated allosteric network. To control TS allostery with light, we incorporated the unnatural amino acid o-nitrobenzyl-O-tyrosine (ONBY) at seven strategic positions of TrpA and TrpB. Initial screening experiments showed that ONBY in position 58 of TrpA (aL58ONBY) inhibits TS activity most effectively. Upon UV irradiation, ONBY decages to tyrosine, largely restoring the capacity of TS. Biochemical characterization, extensive steady-state enzyme kinetics, and titration studies uncovered the impact of aL58ONBY on the activities of TrpA and TrpB and identified reaction conditions under which the influence of ONBY decaging on allostery reaches its full potential. By applying those optimal conditions, we succeeded to directly light-activate TS(aL58ONBY) by a factor of ~100. Our findings show that rational protein design with a photo-sensitive unnatural amino acid combined with extensive enzymology is a powerful tool to fine-tune allosteric light-activation of a central metabolic enzyme complex.
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Affiliation(s)
- Andrea C Kneuttinger
- Institute of Biophysics and Physical Biochemistry, University of Regensburg, Universitätsstraße 31, 93053 Regensburg, Germany.
| | - Stefanie Zwisele
- Institute of Biophysics and Physical Biochemistry, University of Regensburg, Universitätsstraße 31, 93053 Regensburg, Germany.
| | - Kristina Straub
- Institute of Biophysics and Physical Biochemistry, University of Regensburg, Universitätsstraße 31, 93053 Regensburg, Germany.
| | - Astrid Bruckmann
- Institute of Biochemistry, Genetics and Microbiology, University of Regensburg, Universitätsstraße 31, 93053 Regensburg, Germany.
| | - Florian Busch
- Department of Chemistry and Biochemistry and Resource for Native Mass Spectrometry Guided Structural Biology, The Ohio State University, Columbus, OH 43210, USA.
| | - Thomas Kinateder
- Institute of Biophysics and Physical Biochemistry, University of Regensburg, Universitätsstraße 31, 93053 Regensburg, Germany.
| | - Barbara Gaim
- Institute of Biophysics and Physical Biochemistry, University of Regensburg, Universitätsstraße 31, 93053 Regensburg, Germany.
| | - Vicki H Wysocki
- Department of Chemistry and Biochemistry and Resource for Native Mass Spectrometry Guided Structural Biology, The Ohio State University, Columbus, OH 43210, USA.
| | - Rainer Merkl
- Institute of Biophysics and Physical Biochemistry, University of Regensburg, Universitätsstraße 31, 93053 Regensburg, Germany.
| | - Reinhard Sterner
- Institute of Biophysics and Physical Biochemistry, University of Regensburg, Universitätsstraße 31, 93053 Regensburg, Germany.
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50
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Romney DK, Sarai NS, Arnold FH. Nitroalkanes as Versatile Nucleophiles for Enzymatic Synthesis of Noncanonical Amino Acids. ACS Catal 2019; 9:8726-8730. [PMID: 33274115 DOI: 10.1021/acscatal.9b02089] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
C-C bond-forming reactions often require nucleophilic carbon species rarely compatible with aqueous reaction media, thus restricting their appearance in biocatalysis. Here we report the use of nitroalkanes as a structurally versatile class of nucleophilic substrates for C-C bond formation catalyzed by variants of the β-subunit of tryptophan synthase (TrpB). The enzymes accept a wide range of nitroalkanes to form noncanonical amino acids, here the nitro group can serve as a handle for further modification. Using nitroalkane nucleophiles greatly expands the scope of compounds made by TrpB variants and establishes nitroalkanes as a valuable substrate class for biocatalytic C-C bond formation.
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Affiliation(s)
- David K. Romney
- Division of Chemistry and Chemical Engineering 210-41, California Institute of Technology, 1200 East California Boulevard, Pasadena, California 91125, United States
| | - Nicholas S. Sarai
- Division of Chemistry and Chemical Engineering 210-41, California Institute of Technology, 1200 East California Boulevard, Pasadena, California 91125, United States
| | - Frances H. Arnold
- Division of Chemistry and Chemical Engineering 210-41, California Institute of Technology, 1200 East California Boulevard, Pasadena, California 91125, United States
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