1
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Bowling PE, Dasgupta S, Herbert JM. Eliminating Imaginary Vibrational Frequencies in Quantum-Chemical Cluster Models of Enzymatic Active Sites. J Chem Inf Model 2024; 64:3912-3922. [PMID: 38648614 DOI: 10.1021/acs.jcim.4c00221] [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: 04/25/2024]
Abstract
In constructing finite models of enzyme active sites for quantum-chemical calculations, atoms at the periphery of the model must be constrained to prevent unphysical rearrangements during geometry relaxation. A simple fixed-atom or "coordinate-lock" approach is commonly employed but leads to undesirable artifacts in the form of small imaginary frequencies. These preclude evaluation of finite-temperature free-energy corrections, limiting thermochemical calculations to enthalpies only. Full-dimensional vibrational frequency calculations are possible by replacing the fixed-atom constraints with harmonic confining potentials. Here, we compare that approach to an alternative strategy in which fixed-atom contributions to the Hessian are simply omitted. While the latter strategy does eliminate imaginary frequencies, it tends to underestimate both the zero-point energy and the vibrational entropy while introducing artificial rigidity. Harmonic confining potentials eliminate imaginary frequencies and provide a flexible means to construct active-site models that can be used in unconstrained geometry relaxations, affording better convergence of reaction energies and barrier heights with respect to the model size, as compared to models with fixed-atom constraints.
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Affiliation(s)
- Paige E Bowling
- Biophysics Graduate Program, The Ohio State University, Columbus, Ohio 43210, United States
- Department of Chemistry and Biochemistry, The Ohio State University, Columbus, Ohio 43210, United States
| | - Saswata Dasgupta
- Department of Chemistry and Biochemistry, The Ohio State University, Columbus, Ohio 43210, United States
- Department of Chemistry and Biochemistry, University of California-San Diego, La Jolla, California 92093, United States
| | - John M Herbert
- Biophysics Graduate Program, The Ohio State University, Columbus, Ohio 43210, United States
- Department of Chemistry and Biochemistry, The Ohio State University, Columbus, Ohio 43210, United States
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2
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Kojima M, Abe S, Furuta T, Tran DP, Hirata K, Yamashita K, Hishikawa Y, Kitao A, Ueno T. Engineering of an in-cell protein crystal for fastening a metastable conformation of a target miniprotein. Biomater Sci 2023; 11:1350-1357. [PMID: 36594419 DOI: 10.1039/d2bm01759h] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Protein crystals can be utilized as porous scaffolds to capture exogenous molecules. Immobilization of target proteins using protein crystals is expected to facilitate X-ray structure analysis of proteins that are difficult to be crystallized. One of the advantages of scaffold-assisted structure determination is the analysis of metastable structures that are not observed in solution. However, efforts to fix target proteins within the pores of scaffold protein crystals have been limited due to the lack of strategies to control protein-protein interactions formed in the crystals. In this study, we analyze the metastable structure of the miniprotein, CLN025, which forms a β-hairpin structure in solution, using a polyhedra crystal (PhC), an in-cell protein crystal. CLN025 is successfully fixed within the PhC scaffold by replacing the original loop region. X-ray crystal structure analysis and molecular dynamics (MD) simulation reveal that CLN025 is fixed as a helical structure in a metastable state by non-covalent interactions in the scaffold crystal. These results indicate that modulation of intermolecular interactions can trap various protein conformations in the engineered PhC and provides a new strategy for scaffold-assisted structure determination.
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Affiliation(s)
- Mariko Kojima
- School of Life Science and Technology, Tokyo Institute of Technology, Nagatsuta-cho 4259, Midori-ku, Yokohama 226-8501, Japan.
| | - Satoshi Abe
- School of Life Science and Technology, Tokyo Institute of Technology, Nagatsuta-cho 4259, Midori-ku, Yokohama 226-8501, Japan.
| | - Tadaomi Furuta
- School of Life Science and Technology, Tokyo Institute of Technology, Nagatsuta-cho 4259, Midori-ku, Yokohama 226-8501, Japan.
| | - Duy Phuoc Tran
- School of Life Science and Technology, Tokyo Institute of Technology, Nagatsuta-cho 4259, Midori-ku, Yokohama 226-8501, Japan.
| | - Kunio Hirata
- SR Life Science Instrumentation Unit, RIKEN/SPring-8 Center, 1-1-1, Kouto, Sayo-cho, Sayo-gun, Hyogo 679-5148, Japan
| | - Keitaro Yamashita
- SR Life Science Instrumentation Unit, RIKEN/SPring-8 Center, 1-1-1, Kouto, Sayo-cho, Sayo-gun, Hyogo 679-5148, Japan.,MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge CB2 0QH, UK
| | - Yuki Hishikawa
- School of Life Science and Technology, Tokyo Institute of Technology, Nagatsuta-cho 4259, Midori-ku, Yokohama 226-8501, Japan.
| | - Akio Kitao
- School of Life Science and Technology, Tokyo Institute of Technology, Nagatsuta-cho 4259, Midori-ku, Yokohama 226-8501, Japan.
| | - Takafumi Ueno
- School of Life Science and Technology, Tokyo Institute of Technology, Nagatsuta-cho 4259, Midori-ku, Yokohama 226-8501, Japan. .,International Research Frontiers Initiative (IRFI), Tokyo Institute of Technology, Nagatsuta-cho 4259, Midori-ku, Yokohama 226-8501, Japan
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3
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Opuu V, Simonson T. Enzyme redesign and genetic code expansion. Protein Eng Des Sel 2023; 36:gzad017. [PMID: 37879093 DOI: 10.1093/protein/gzad017] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2023] [Revised: 09/10/2023] [Accepted: 09/19/2023] [Indexed: 10/27/2023] Open
Abstract
Enzyme design is an important application of computational protein design (CPD). It can benefit enormously from the additional chemistries provided by noncanonical amino acids (ncAAs). These can be incorporated into an 'expanded' genetic code, and introduced in vivo into target proteins. The key step for genetic code expansion is to engineer an aminoacyl-transfer RNA (tRNA) synthetase (aaRS) and an associated tRNA that handles the ncAA. Experimental directed evolution has been successfully used to engineer aaRSs and incorporate over 200 ncAAs into expanded codes. But directed evolution has severe limits, and is not yet applicable to noncanonical AA backbones. CPD can help address several of its limitations, and has begun to be applied to this problem. We review efforts to redesign aaRSs, studies that designed new proteins and functionalities with the help of ncAAs, and some of the method developments that have been used, such as adaptive landscape flattening Monte Carlo, which allows an enzyme to be redesigned with substrate or transition state binding as the design target.
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Affiliation(s)
- Vaitea Opuu
- Institut Chimie Biologie Innovation (CNRS UMR8231), Ecole Supérieure de Physique et Chimie de Paris (ESPCI), 75005 Paris, France
| | - Thomas Simonson
- Laboratoire de Biologie Structurale de la Cellule (CNRS UMR7654), Ecole Polytechnique, Institut Polytechnique de Paris, 91128 Palaiseau, France
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4
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Liu X, Liu P, Li H, Xu Z, Jia L, Xia Y, Yu M, Tang W, Zhu X, Chen C, Zhang Y, Nango E, Tanaka R, Luo F, Kato K, Nakajima Y, Kishi S, Yu H, Matsubara N, Owada S, Tono K, Iwata S, Yu LJ, Shen JR, Wang J. Excited-state intermediates in a designer protein encoding a phototrigger caught by an X-ray free-electron laser. Nat Chem 2022; 14:1054-1060. [DOI: 10.1038/s41557-022-00992-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2021] [Accepted: 06/01/2022] [Indexed: 11/09/2022]
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5
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Yao Z, Caldwell DR, Love AC, Kolbaba-Kartchner B, Mills JH, Schnermann MJ, Prescher JA. Coumarin luciferins and mutant luciferases for robust multi-component bioluminescence imaging. Chem Sci 2021; 12:11684-11691. [PMID: 34659703 PMCID: PMC8442684 DOI: 10.1039/d1sc03114g] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2021] [Accepted: 07/20/2021] [Indexed: 12/21/2022] Open
Abstract
Multi-component bioluminescence imaging requires an expanded collection of luciferase-luciferin pairs that emit far-red or near-infrared light. Toward this end, we prepared a new class of luciferins based on a red-shifted coumarin scaffold. These probes (CouLuc-1s) were accessed in a two-step sequence via direct modification of commercial dyes. The bioluminescent properties of the CouLuc-1 analogs were also characterized, and complementary luciferase enzymes were identified using a two-pronged screening strategy. The optimized enzyme-substrate pairs displayed robust photon outputs and emitted a significant portion of near-infrared light. The CouLuc-1 scaffolds are also structurally distinct from existing probes, enabling rapid multi-component imaging. Collectively, this work provides novel bioluminescent tools along with a blueprint for crafting additional fluorophore-derived probes for multiplexed imaging.
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Affiliation(s)
- Zi Yao
- Department of Chemistry, University of California Irvine CA USA
| | - Donald R Caldwell
- Chemical Biology Laboratory, Center for Cancer Research, National Cancer Institute Frederick MD USA
| | - Anna C Love
- Department of Chemistry, University of California Irvine CA USA
| | - Bethany Kolbaba-Kartchner
- School of Molecular Sciences, Arizona State University Tempe AZ USA
- The Biodesign Center for Molecular Design and Biomimetics, Arizona State University Tempe AZ USA
| | - Jeremy H Mills
- School of Molecular Sciences, Arizona State University Tempe AZ USA
- The Biodesign Center for Molecular Design and Biomimetics, Arizona State University Tempe AZ USA
| | - Martin J Schnermann
- Chemical Biology Laboratory, Center for Cancer Research, National Cancer Institute Frederick MD USA
| | - Jennifer A Prescher
- Department of Chemistry, University of California Irvine CA USA
- Department of Molecular Biology & Biochemistry, University of California Irvine CA USA
- Department of Pharmaceutical Sciences, University of California Irvine CA USA
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6
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An X, Chen C, Wang T, Huang A, Zhang D, Han MJ, Wang J. Genetic Incorporation of Selenotyrosine Significantly Improves Enzymatic Activity of Agrobacterium radiobacter Phosphotriesterase. Chembiochem 2021; 22:2535-2539. [PMID: 32789938 DOI: 10.1002/cbic.202000460] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2020] [Revised: 08/11/2020] [Indexed: 12/16/2022]
Abstract
Tyrosine plays important roles in many enzymes. To facilitate enzyme design, mechanistic studies and minimize structural perturbation in the active site, here we report the genetic incorporation of a novel unnatural amino acid selenotyrosine (SeHF), which has single-atom replacement in comparison to tyrosine. The arPTE-(Agrobacterium radiobacter Phosphotriesterase) Tyr309SeHF mutant exhibits a significant 12-fold increase in kcat and 3.2-fold enhancement in kcat /KM at pH 7.0. Molecular dynamics simulations show that the SeHF309 mutation results in a conformational switch which opens up the product release pocket and increases the product release rate, thereby elevating the overall enzyme activity. Significant improvement of the catalytic efficiency at neutral pH by single unnatural amino acid (UAA) mutation broadens the application of this enzyme, and provides valuable insights to the mechanism. Our method represents a new approach for designing enzymes with enhanced activity.
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Affiliation(s)
- Xiaojing An
- Laboratory of Non-coding RNA, Institute of Biophysics, Chinese Academy of Sciences, 15 Datun Road, Chaoyang District, Beijing, 100101, China
| | - Chao Chen
- Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, 32 West 7th Avenue, Tianjin Airport Economic Area, Tianjin, 300308, China.,University of the Chinese Academy of Sciences (UCAS), Hefei, China
| | - Tianyuan Wang
- Laboratory of Non-coding RNA, Institute of Biophysics, Chinese Academy of Sciences, 15 Datun Road, Chaoyang District, Beijing, 100101, China
| | - Aiping Huang
- Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, 32 West 7th Avenue, Tianjin Airport Economic Area, Tianjin, 300308, China
| | - Dawei Zhang
- Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, 32 West 7th Avenue, Tianjin Airport Economic Area, Tianjin, 300308, China
| | - Ming-Jie Han
- Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, 32 West 7th Avenue, Tianjin Airport Economic Area, Tianjin, 300308, China
| | - Jiangyun Wang
- Laboratory of Non-coding RNA, Institute of Biophysics, Chinese Academy of Sciences, 15 Datun Road, Chaoyang District, Beijing, 100101, China
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7
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Wang X, Li W. Development and Testing of Force Field Parameters for Phenylalanine and Tyrosine Derivatives. Front Mol Biosci 2021; 7:608931. [PMID: 33385013 PMCID: PMC7770134 DOI: 10.3389/fmolb.2020.608931] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2020] [Accepted: 10/23/2020] [Indexed: 11/13/2022] Open
Abstract
Theoretical analyses are valuable for the exploration of the effects of unnatural amino acids on enzyme functions; however, many necessary parameters for unnatural amino acids remain lacking. In this study, we developed and tested force field parameters compatible with Amber ff14SB for 18 phenylalanine and tyrosine derivatives. The charge parameters were derived from ab initio calculations using the RESP fitting approach and then adjusted to reproduce the benchmark relative energies (at the MP2/TZ level) of the α- and β-backbones for each unnatural amino acid dipeptide. The structures optimized under the proposed force field parameters for the 18 unnatural amino acid dipeptides in both the α- and β-backbone forms were in good agreement with their QM structures, as the average RMSD was as small as 0.1 Å. The force field parameters were then tested in their application to seven proteins containing unnatural amino acids. The RMSDs of the simulated configurations of these unnatural amino acids were approximately 1.0 Å compared with those of the crystal structures. The vital interactions between proteins and unnatural amino acids in five protein–ligand complexes were also predicted using MM/PBSA analysis, and they were largely consistent with experimental observations. This work will provide theoretical aid for drug design involving unnatural amino acids.
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Affiliation(s)
- Xiaowen Wang
- Institute for Advanced Study, Shenzhen University, Shenzhen, China.,College of Physics and Optoelectronic Engineering, Shenzhen University, Shenzhen, China
| | - Wenjin Li
- Institute for Advanced Study, Shenzhen University, Shenzhen, China
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8
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Titrating bacterial growth and chemical biosynthesis for efficient N-acetylglucosamine and N-acetylneuraminic acid bioproduction. Nat Commun 2020; 11:5078. [PMID: 33033266 PMCID: PMC7544899 DOI: 10.1038/s41467-020-18960-1] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2020] [Accepted: 09/21/2020] [Indexed: 12/27/2022] Open
Abstract
Metabolic engineering facilitates chemical biosynthesis by rewiring cellular resources to produce target compounds. However, an imbalance between cell growth and bioproduction often reduces production efficiency. Genetic code expansion (GCE)-based orthogonal translation systems incorporating non-canonical amino acids (ncAAs) into proteins by reassigning non-canonical codons to ncAAs qualify for balancing cellular metabolism. Here, GCE-based cell growth and biosynthesis balance engineering (GCE-CGBBE) is developed, which is based on titrating expression of cell growth and metabolic flux determinant genes by constructing ncAA-dependent expression patterns. We demonstrate GCE-CGBBE in genome-recoded Escherichia coli Δ321AM by precisely balancing glycolysis and N-acetylglucosamine production, resulting in a 4.54-fold increase in titer. GCE-CGBBE is further expanded to non-genome-recoded Bacillus subtilis to balance growth and N-acetylneuraminic acid bioproduction by titrating essential gene expression, yielding a 2.34-fold increase in titer. Moreover, the development of ncAA-dependent essential gene expression regulation shows efficient biocontainment of engineered B. subtilis to avoid unintended proliferation in nature. An imbalance between cell growth and bioproduction of engineered microbes often reduces production efficiency. Here, the authors report genetic code expansion-based cell growth and biosynthesis balance engineering to achieve high levels production of N-acetylglucosamine in E. coli and N-acetylneuraminic acid in B. subtilis.
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9
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Henderson JN, Simmons CR, Fahmi NE, Jeffs JW, Borges CR, Mills JH. Structural Insights into How Protein Environments Tune the Spectroscopic Properties of a Noncanonical Amino Acid Fluorophore. Biochemistry 2020; 59:3401-3410. [PMID: 32845612 DOI: 10.1021/acs.biochem.0c00474] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Genetically encoded fluorescent noncanonical amino acids (fNCAAs) could be used to develop novel fluorescent sensors of protein function. Previous efforts toward this goal have been limited by the lack of extensive physicochemical and structural characterizations of protein-based sensors containing fNCAAs. Here, we report the steady-state spectroscopic properties and first structural analyses of an fNCAA-containing Fab fragment of the 5c8 antibody, which binds human CD40L. A previously reported 5c8 variant in which the light chain residue IleL98 is replaced with the fNCAA l-(7-hydroxycoumarin-4-yl)ethylglycine (7-HCAA) exhibits a 1.7-fold increase in fluorescence upon antigen binding. Determination and comparison of the apparent pKas of 7-HCAA in the unbound and bound forms indicate that the observed increase in fluorescence is not the result of perturbations in pKa. Crystal structures of the fNCAA-containing Fab in the apo and bound forms reveal interactions between the 7-HCAA side chain and surrounding residues that are disrupted upon antigen binding. This structural characterization not only provides insight into the manner in which protein environments can modulate the fluorescence properties of 7-HCAA but also could serve as a starting point for the rational design of new fluorescent protein-based reporters of protein function.
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Affiliation(s)
- J Nathan Henderson
- The Biodesign Center for Molecular Design and Biomimetics, Arizona State University, Tempe, Arizona 85287, United States
| | - Chad R Simmons
- The Biodesign Center for Molecular Design and Biomimetics, Arizona State University, Tempe, Arizona 85287, United States
| | - Nour Eddine Fahmi
- The Biodesign Center for Molecular Design and Biomimetics, Arizona State University, Tempe, Arizona 85287, United States
| | - Joshua W Jeffs
- The Biodesign Virginia G. Piper Center for Personalized Diagnostics, Arizona State University, Tempe, Arizona 85287, United States.,School of Molecular Sciences, Arizona State University, Tempe, Arizona 85287, United States
| | - Chad R Borges
- The Biodesign Virginia G. Piper Center for Personalized Diagnostics, Arizona State University, Tempe, Arizona 85287, United States.,School of Molecular Sciences, Arizona State University, Tempe, Arizona 85287, United States
| | - Jeremy H Mills
- The Biodesign Center for Molecular Design and Biomimetics, Arizona State University, Tempe, Arizona 85287, United States.,School of Molecular Sciences, Arizona State University, Tempe, Arizona 85287, United States
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10
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Yao Z, Zhang BS, Steinhardt RC, Mills JH, Prescher JA. Multicomponent Bioluminescence Imaging with a π-Extended Luciferin. J Am Chem Soc 2020; 142:14080-14089. [PMID: 32787261 PMCID: PMC7867379 DOI: 10.1021/jacs.0c01064] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Bioluminescence imaging with luciferase-luciferin pairs is commonly used for monitoring biological processes in cells and whole organisms. Traditional bioluminescent probes are limited in scope, though, as they cannot be easily distinguished in biological environments, precluding efforts to visualize multicellular processes. Additionally, many luciferase-luciferin pairs emit light that is poorly tissue penetrant, hindering efforts to visualize targets in deep tissues. To address these issues, we synthesized a set of π-extended luciferins that were predicted to be red-shifted luminophores. The scaffolds were designed to be rotationally labile such that they produced light only when paired with luciferases capable of enforcing planarity. A luciferin comprising an intramolecular "lock" was identified as a viable light-emitting probe. Native luciferases were unable to efficiently process the analog, but a complementary luciferase was identified via Rosetta-guided enzyme design. The unique enzyme-substrate pair is red-shifted compared to well-known bioluminescent tools. The probe set is also orthogonal to other luciferase-luciferin probes and can be used for multicomponent imaging. Four substrate-resolved luciferases were imaged in a single session. Collectively, this work provides the first example of Rosetta-guided design in engineering bioluminescent tools and expands the scope of orthogonal imaging probes.
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Affiliation(s)
- Zi Yao
- Department of Chemistry, University of California, Irvine, California 92697, United States
| | - Brendan S. Zhang
- Department of Chemistry, University of California, Irvine, California 92697, United States
| | - Rachel C. Steinhardt
- Department of Chemistry, University of California, Irvine, California 92697, United States
| | - Jeremy H. Mills
- Department of Chemistry and Biochemistry, Arizona State University, Tempe AZ, USA
- The Center for Molecular Design and Biomimetics, Arizona State University, Tempe AZ, USA
- The Biodesign Institute, Arizona State University, Tempe AZ, USA
| | - Jennifer A. Prescher
- Department of Chemistry, University of California, Irvine, California 92697, United States
- Department of Molecular Biology & Biochemistry, University of California, Irvine, California 92697, United States
- Department of Pharmaceutical Sciences, University of California, Irvine, California 92697, United States
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11
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Protein engineering: the potential of remote mutations. Biochem Soc Trans 2019; 47:701-711. [PMID: 30902926 DOI: 10.1042/bst20180614] [Citation(s) in RCA: 43] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2019] [Revised: 01/18/2019] [Accepted: 02/18/2019] [Indexed: 12/19/2022]
Abstract
Engineered proteins, especially enzymes, are now commonly used in many industries owing to their catalytic power, specific binding of ligands, and properties as materials and food additives. As the number of potential uses for engineered proteins has increased, the interest in engineering or designing proteins to have greater stability, activity and specificity has increased in turn. With any rational engineering or design pursuit, the success of these endeavours relies on our fundamental understanding of the systems themselves; in the case of proteins, their structure-dynamics-function relationships. Proteins are most commonly rationally engineered by targeting the residues that we understand to be functionally important, such as enzyme active sites or ligand-binding sites. This means that the majority of the protein, i.e. regions remote from the active- or ligand-binding site, is often ignored. However, there is a growing body of literature that reports on, and rationalises, the successful engineering of proteins at remote sites. This minireview will discuss the current state of the art in protein engineering, with a particular focus on engineering regions that are remote from active- or ligand-binding sites. As the use of protein technologies expands, exploiting the potential improvements made possible through modifying remote regions will become vital if we are to realise the full potential of protein engineering and design.
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12
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Liu X, Kang F, Hu C, Wang L, Xu Z, Zheng D, Gong W, Lu Y, Ma Y, Wang J. A genetically encoded photosensitizer protein facilitates the rational design of a miniature photocatalytic CO 2-reducing enzyme. Nat Chem 2018; 10:1201-1206. [PMID: 30397317 DOI: 10.1038/s41557-018-0150-4] [Citation(s) in RCA: 66] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2018] [Accepted: 08/30/2018] [Indexed: 12/31/2022]
Abstract
Photosensitizers, which harness light energy to upgrade weak reductants to strong reductants, are pivotal components of the natural and artificial photosynthesis machineries. However, it has proved difficult to enhance and expand their functions through genetic engineering. Here we report a genetically encoded, 27 kDa photosensitizer protein (PSP), which facilitates the rational design of miniature photocatalytic CO2-reducing enzymes. Visible light drives PSP efficiently into a long-lived triplet excited state (PSP*), which reacts rapidly with reduced nicotinamide adenine dinucleotide to generate a super-reducing radical (PSP•), which is strong enough to reduce many CO2-reducing catalysts. We determined the three-dimensional structure of PSP• at 1.8 Å resolution by X-ray crystallography. Genetic engineering enabled the site-specific attachment of a nickel-terpyridine complex and the modular optimization of the photochemical properties of PSP, the chromophore/catalytic centre distance and the catalytic centre microenvironment, which culminated in a miniature photocatalytic CO2-reducing enzyme that has a CO2/CO conversion quantum efficiency of 2.6%.
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Affiliation(s)
- Xiaohong Liu
- Laboratory of RNA Biology, Institute of Biophysics, Chinese Academy of Science, Chaoyang District, Beijing, China
| | - Fuying Kang
- Laboratory of RNA Biology, Institute of Biophysics, Chinese Academy of Science, Chaoyang District, Beijing, China.,College of Life Sciences and School of Future Technology, University of Chinese Academy of Sciences, Beijing, China
| | - Cheng Hu
- Laboratory of RNA Biology, Institute of Biophysics, Chinese Academy of Science, Chaoyang District, Beijing, China.,College of Life Sciences and School of Future Technology, University of Chinese Academy of Sciences, Beijing, China
| | - Li Wang
- Laboratory of RNA Biology, Institute of Biophysics, Chinese Academy of Science, Chaoyang District, Beijing, China.,College of Life Sciences and School of Future Technology, University of Chinese Academy of Sciences, Beijing, China
| | - Zhen Xu
- Laboratory of RNA Biology, Institute of Biophysics, Chinese Academy of Science, Chaoyang District, Beijing, China
| | - Dandan Zheng
- Laboratory of RNA Biology, Institute of Biophysics, Chinese Academy of Science, Chaoyang District, Beijing, China
| | - Weimin Gong
- Hefei National Laboratory for Physical Sciences at the Microscale, University of Science & Technology of China, Hefei, Anhui, China
| | - Yi Lu
- Center of Chemical Biology, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, China
| | - Yanhe Ma
- Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, China
| | - Jiangyun Wang
- Laboratory of RNA Biology, Institute of Biophysics, Chinese Academy of Science, Chaoyang District, Beijing, China. .,College of Life Sciences and School of Future Technology, University of Chinese Academy of Sciences, Beijing, China. .,Shenzhen Institute of Transfusion Medicine, Shenzhen Blood Center, Shenzhen, Guangdong, China.
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13
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Keedy DA, Hill ZB, Biel JT, Kang E, Rettenmaier TJ, Brandão-Neto J, Pearce NM, von Delft F, Wells JA, Fraser JS. An expanded allosteric network in PTP1B by multitemperature crystallography, fragment screening, and covalent tethering. eLife 2018; 7:36307. [PMID: 29877794 PMCID: PMC6039181 DOI: 10.7554/elife.36307] [Citation(s) in RCA: 90] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2018] [Accepted: 06/04/2018] [Indexed: 12/28/2022] Open
Abstract
Allostery is an inherent feature of proteins, but it remains challenging to reveal the mechanisms by which allosteric signals propagate. A clearer understanding of this intrinsic circuitry would afford new opportunities to modulate protein function. Here, we have identified allosteric sites in protein tyrosine phosphatase 1B (PTP1B) by combining multiple-temperature X-ray crystallography experiments and structure determination from hundreds of individual small-molecule fragment soaks. New modeling approaches reveal 'hidden' low-occupancy conformational states for protein and ligands. Our results converge on allosteric sites that are conformationally coupled to the active-site WPD loop and are hotspots for fragment binding. Targeting one of these sites with covalently tethered molecules or mutations allosterically inhibits enzyme activity. Overall, this work demonstrates how the ensemble nature of macromolecular structure, revealed here by multitemperature crystallography, can elucidate allosteric mechanisms and open new doors for long-range control of protein function. Proteins perform many important jobs in each of the cells in our bodies, such as transporting other molecules and helping chemical reactions to occur. The part of the protein directly involved in these tasks is called the active site. Other areas of the protein can communicate with the active site to switch the protein on or off. This method of control is known as allostery. Switching proteins on and off could help us to develop treatments for certain diseases. For example, a protein called PTP1B reduces how well cells can respond to insulin. Switching this protein off could therefore help to treat diabetes. However, much like it’s hard to guess how a light switch is wired to a light bulb without seeing behind the walls, it is hard to predict which remote areas of a protein are ‘wired’ to the active site. Keedy, Hill et al. have now used two complementary methods to examine the structure of PTP1B and find new allosteric sites. The first method captured a series of X-ray images from crystallized molecules of the protein held at different temperatures. This revealed areas of PTP1B that can move like windshield wipers to communicate with each other. The second method soaked PTP1B crystals in trays with hundreds of drug-sized molecules and assessed which sites on the protein the molecules bound to. The molecules generally bound to just a few sites of the protein. Further tests on one of these sites showed that it can communicate with the active site to turn the protein on or off. Further work will be needed to develop drugs that could treat diabetes by binding to the newly identified allosteric sites in PTP1B. More generally, the methods developed by Keedy, Hill et al. could be used to study allostery in other important proteins.
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Affiliation(s)
- Daniel A Keedy
- Department of Bioengineering and Therapeutic Sciences, University of California, San Francisco, San Francisco, United States
| | - Zachary B Hill
- Department of Pharmaceutical Chemistry, University of California, San Francisco, San Francisco, United States
| | - Justin T Biel
- Department of Bioengineering and Therapeutic Sciences, University of California, San Francisco, San Francisco, United States
| | - Emily Kang
- Department of Pharmaceutical Chemistry, University of California, San Francisco, San Francisco, United States
| | - T Justin Rettenmaier
- Cellular and Molecular Pharmacology, University of California, San Francisco, San Francisco, United States
| | | | - Nicholas M Pearce
- Crystal and Structural Chemistry Group, Bijvoet Center for Biomolecular Research, Utrecht University, Utrecht, Netherlands
| | - Frank von Delft
- Diamond Light Source, Didcot, United Kingdom.,Structural Genomics Consortium, University of Oxford, Oxford, United Kingdom.,Department of Biochemistry, University of Johannesburg, Johannesburg, South Africa
| | - James A Wells
- Department of Pharmaceutical Chemistry, University of California, San Francisco, San Francisco, United States.,Cellular and Molecular Pharmacology, University of California, San Francisco, San Francisco, United States
| | - James S Fraser
- Department of Bioengineering and Therapeutic Sciences, University of California, San Francisco, San Francisco, United States
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14
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Abstract
Our understanding of the complex molecular processes of living organisms at the molecular level is growing exponentially. This knowledge, together with a powerful arsenal of tools for manipulating the structures of macromolecules, is allowing chemists to to harness and reprogram the cellular machinery in ways previously unimaged. Here we review one example in which the genetic code itself has been expanded with new building blocks that allow us to probe and manipulate the structures and functions of proteins with unprecedented precision.
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Affiliation(s)
- Douglas D. Young
- Department of Chemistry, College of William & Mary,
P.O. Box 8795, Williamsburg, VA 23187 (USA)
| | - Peter G. Schultz
- Department of Chemistry, The Scripps Research Institute,
La Jolla, CA 92037 (USA),
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15
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Summers TJ, Cheng Q, DeYonker NJ. A transition state “trapped”? QM-cluster models of engineered threonyl-tRNA synthetase. Org Biomol Chem 2018; 16:4090-4100. [DOI: 10.1039/c8ob00540k] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
QM-cluster models demonstrate how protein bioengineering alters the local energy landscape of p-biphenylalanine to stabilize a transition state analogue.
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Affiliation(s)
| | - Qianyi Cheng
- The Department of Chemistry
- The University of Memphis
- Memphis
- USA
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16
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Chin JW. Expanding and reprogramming the genetic code. Nature 2017; 550:53-60. [PMID: 28980641 DOI: 10.1038/nature24031] [Citation(s) in RCA: 488] [Impact Index Per Article: 69.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2017] [Accepted: 08/22/2017] [Indexed: 12/13/2022]
Abstract
Nature uses a limited, conservative set of amino acids to synthesize proteins. The ability to genetically encode an expanded set of building blocks with new chemical and physical properties is transforming the study, manipulation and evolution of proteins, and is enabling diverse applications, including approaches to probe, image and control protein function, and to precisely engineer therapeutics. Underpinning this transformation are strategies to engineer and rewire translation. Emerging strategies aim to reprogram the genetic code so that noncanonical biopolymers can be synthesized and evolved, and to test the limits of our ability to engineer the translational machinery and systematically recode genomes.
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Affiliation(s)
- Jason W Chin
- Medical Research Council Laboratory of Molecular Biology, Cambridge CB2 0QH, UK.,Department of Chemistry, Cambridge University, Cambridge CB2 1EW, UK
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17
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Abstract
The genetic code-the language used by cells to translate their genomes into proteins that perform many cellular functions-is highly conserved throughout natural life. Rewriting the genetic code could lead to new biological functions such as expanding protein chemistries with noncanonical amino acids (ncAAs) and genetically isolating synthetic organisms from natural organisms and viruses. It has long been possible to transiently produce proteins bearing ncAAs, but stabilizing an expanded genetic code for sustained function in vivo requires an integrated approach: creating recoded genomes and introducing new translation machinery that function together without compromising viability or clashing with endogenous pathways. In this review, we discuss design considerations and technologies for expanding the genetic code. The knowledge obtained by rewriting the genetic code will deepen our understanding of how genomes are designed and how the canonical genetic code evolved.
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Affiliation(s)
- Takahito Mukai
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, Connecticut 06511;
| | - Marc J Lajoie
- Department of Biochemistry, University of Washington, Seattle, Washington 98195
| | - Markus Englert
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, Connecticut 06511;
| | - Dieter Söll
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, Connecticut 06511; .,Department of Chemistry, Yale University, New Haven, Connecticut 06511
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18
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Pan LL, Song LF, Miao Y, Yang Y, Merz KM. Mechanism of Formation of the Nonstandard Product in the Prenyltransferase Reaction of the G115T Mutant of FtmPT1: A Case of Reaction Dynamics Calling the Shots? Biochemistry 2017; 56:2995-3007. [PMID: 28570807 DOI: 10.1021/acs.biochem.7b00248] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
FtmPT1 is a fungal indole prenyltransferase that affords Tryprostatin B from Brevianamide F and dimethylallyl pyrophosphate; however, when a single residue in the active site is mutated (Gly115Thr), a novel five-membered ring compound is obtained as the major product with Tryprostatin B as the minor product. Herein, we describe detailed studies of the catalysis of the Gly115Thr mutant of FtmPT1 with a focus on the observed regioselectivity of the reaction. We employ one- and two-dimensional potential of mean force simulations to explore the catalytic mechanism, along with molecular dynamics simulations exploring the reaction dynamics of the prenyl transfer reaction. Single-point electronic structure calculations were also used to explore the performance of the self-consistent charge density functional tight-binding method to model specific reaction steps. Importantly, we observe that the two reaction pathways have comparable activation parameters and propose that the origin of the novel product is predicated, at least in part, on the topology of the potential energy surface as revealed by reaction dynamics studies.
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Affiliation(s)
- Li-Li Pan
- Department of Chemistry and Department of Biochemistry and Molecular Biology, Michigan State University , 578 South Shaw Lane, East Lansing, Michigan 48824, United States
| | - Lin Frank Song
- Department of Chemistry and Department of Biochemistry and Molecular Biology, Michigan State University , 578 South Shaw Lane, East Lansing, Michigan 48824, United States
| | - Yipu Miao
- Department of Chemistry and Department of Biochemistry and Molecular Biology, Michigan State University , 578 South Shaw Lane, East Lansing, Michigan 48824, United States
| | - Yue Yang
- Biosciences and Biotechnology Division, Lawrence Livermore National Laboratory , 7000 East Avenue, Livermore, California 94550, United States
| | - Kenneth M Merz
- Department of Chemistry and Department of Biochemistry and Molecular Biology, Michigan State University , 578 South Shaw Lane, East Lansing, Michigan 48824, United States.,Institute for Cyber Enabled Research, Michigan State University , 567 Wilson Road, Room 1440, East Lansing, Michigan 48824, United States
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19
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Paladino A, Marchetti F, Rinaldi S, Colombo G. Protein design: from computer models to artificial intelligence. WILEY INTERDISCIPLINARY REVIEWS-COMPUTATIONAL MOLECULAR SCIENCE 2017. [DOI: 10.1002/wcms.1318] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Affiliation(s)
- Antonella Paladino
- Biomolecular Simulations & Computational Chemistry Group; Istituto Istituto di Chimica del Riconoscimento Molecolare, CNR; Milano Italy
| | - Filippo Marchetti
- Biomolecular Simulations & Computational Chemistry Group; Istituto Istituto di Chimica del Riconoscimento Molecolare, CNR; Milano Italy
| | - Silvia Rinaldi
- Biomolecular Simulations & Computational Chemistry Group; Istituto Istituto di Chimica del Riconoscimento Molecolare, CNR; Milano Italy
| | - Giorgio Colombo
- Biomolecular Simulations & Computational Chemistry Group; Istituto Istituto di Chimica del Riconoscimento Molecolare, CNR; Milano Italy
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20
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Koehl P. Minimum action transition paths connecting minima on an energy surface. J Chem Phys 2017; 145:184111. [PMID: 27846680 DOI: 10.1063/1.4966974] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Dynamics is essential to the biological functions of many bio-molecules, yet our knowledge of dynamics remains fragmented. Experimental techniques for studying bio-molecules either provide high resolution information on static conformations of the molecule or provide low-resolution, ensemble information that does not shed light on single molecule dynamics. In parallel, bio-molecular dynamics occur at time scale that are not yet attainable through detailed simulation methods. These limitations are especially noticeable when studying transition paths. To address this issue, we report in this paper two methods that derive meaningful trajectories for proteins between two of their conformations. The first method, MinActionPath, uses approximations of the potential energy surface for the molecule to derive an analytical solution of the equations of motion related to the concept of minimum action path. The second method, RelaxPath, follows the same principle of minimum action path but implements a more sophisticated potential, including a mixed elastic potential and a collision term to alleviate steric clashes. Using this new potential, the equations of motion cannot be solved analytically. We have introduced a relaxation method for solving those equations. We describe both the theories behind the two methods and their implementations, focusing on the specific techniques we have used that make those implementations amenable to study large molecular systems. We have illustrated the performance of RelaxPath on simple 2D systems. We have also compared MinActionPath and RelaxPath to other methods for generating transition paths on a well suited test set of large proteins, for which the end points of the trajectories as well as an intermediate conformation between those end points are known. We have shown that RelaxPath outperforms those other methods, including MinActionPath, in its ability to generate trajectories that get close to the known intermediates. We have also shown that the structures along the RelaxPath trajectories remain protein-like. Open source versions of the two programs MinActionPath and RelaxPath are available by request.
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Affiliation(s)
- Patrice Koehl
- Department of Computer Science and Genome Center, University of California, Davis, California 95616, USA
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21
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Metrano A, Abascal NC, Mercado BQ, Paulson EK, Hurtley AE, Miller SJ. Diversity of Secondary Structure in Catalytic Peptides with β-Turn-Biased Sequences. J Am Chem Soc 2017; 139:492-516. [PMID: 28029251 PMCID: PMC5312972 DOI: 10.1021/jacs.6b11348] [Citation(s) in RCA: 84] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2016] [Indexed: 11/30/2022]
Abstract
X-ray crystallography has been applied to the structural analysis of a series of tetrapeptides that were previously assessed for catalytic activity in an atroposelective bromination reaction. Common to the series is a central Pro-Xaa sequence, where Pro is either l- or d-proline, which was chosen to favor nucleation of canonical β-turn secondary structures. Crystallographic analysis of 35 different peptide sequences revealed a range of conformational states. The observed differences appear not only in cases where the Pro-Xaa loop-region is altered, but also when seemingly subtle alterations to the flanking residues are introduced. In many instances, distinct conformers of the same sequence were observed, either as symmetry-independent molecules within the same unit cell or as polymorphs. Computational studies using DFT provided additional insight into the analysis of solid-state structural features. Select X-ray crystal structures were compared to the corresponding solution structures derived from measured proton chemical shifts, 3J-values, and 1H-1H-NOESY contacts. These findings imply that the conformational space available to simple peptide-based catalysts is more diverse than precedent might suggest. The direct observation of multiple ground state conformations for peptides of this family, as well as the dynamic processes associated with conformational equilibria, underscore not only the challenge of designing peptide-based catalysts, but also the difficulty in predicting their accessible transition states. These findings implicate the advantages of low-barrier interconversions between conformations of peptide-based catalysts for multistep, enantioselective reactions.
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Affiliation(s)
- Anthony
J. Metrano
- Department of Chemistry, Yale University, P.O.
Box 208107, New Haven, Connecticut 06520-8107, United States
| | - Nadia C. Abascal
- Department of Chemistry, Yale University, P.O.
Box 208107, New Haven, Connecticut 06520-8107, United States
| | - Brandon Q. Mercado
- Department of Chemistry, Yale University, P.O.
Box 208107, New Haven, Connecticut 06520-8107, United States
| | - Eric K. Paulson
- Department of Chemistry, Yale University, P.O.
Box 208107, New Haven, Connecticut 06520-8107, United States
| | - Anna E. Hurtley
- Department of Chemistry, Yale University, P.O.
Box 208107, New Haven, Connecticut 06520-8107, United States
| | - Scott J. Miller
- Department of Chemistry, Yale University, P.O.
Box 208107, New Haven, Connecticut 06520-8107, United States
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22
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Xiao H, Schultz PG. At the Interface of Chemical and Biological Synthesis: An Expanded Genetic Code. Cold Spring Harb Perspect Biol 2016; 8:cshperspect.a023945. [PMID: 27413101 DOI: 10.1101/cshperspect.a023945] [Citation(s) in RCA: 102] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
The ability to site-specifically incorporate noncanonical amino acids (ncAAs) with novel structures into proteins in living cells affords a powerful tool to investigate and manipulate protein structure and function. More than 200 ncAAs with diverse biological, chemical, and physical properties have been genetically encoded in response to nonsense or frameshift codons in both prokaryotic and eukaryotic organisms with high fidelity and efficiency. In this review, recent advances in the technology and its application to problems in protein biochemistry, cellular biology, and medicine are highlighted.
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Affiliation(s)
- Han Xiao
- Department of Chemistry and the Skaggs Institute for Chemical Biology, The Scripps Research Institute, La Jolla, California 92037
| | - Peter G Schultz
- Department of Chemistry and the Skaggs Institute for Chemical Biology, The Scripps Research Institute, La Jolla, California 92037 California Institute for Biomedical Research, La Jolla, California 92037
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23
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Roston D, Cui Q. QM/MM Analysis of Transition States and Transition State Analogues in Metalloenzymes. Methods Enzymol 2016; 577:213-50. [PMID: 27498640 DOI: 10.1016/bs.mie.2016.05.016] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Enzymology is approaching an era where many problems can benefit from computational studies. While ample challenges remain in quantitatively predicting behavior for many enzyme systems, the insights that often come from computations are an important asset for the enzymology community. Here we provide a primer for enzymologists on the types of calculations that are most useful for mechanistic problems in enzymology. In particular, we emphasize the integration of models that range from small active-site motifs to fully solvated enzyme systems for cross-validation and dissection of specific contributions from the enzyme environment. We then use a case study of the enzyme alkaline phosphatase to illustrate specific application of the methods. The case study involves examination of the binding modes of putative transition state analogues (tungstate and vanadate) to the enzyme. The computations predict covalent binding of these ions to the enzymatic nucleophile and that they adopt the trigonal bipyramidal geometry of the expected transition state. By comparing these structures with transition states found through free energy simulations, we assess the degree to which the transition state analogues mimic the true transition states. Technical issues worth treating with care as well as several remaining challenges to quantitative analysis of metalloenzymes are also highlighted during the discussion.
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Affiliation(s)
- D Roston
- Theoretical Chemistry Institute, University of Wisconsin-Madison, Madison, WI, United States.
| | - Q Cui
- Theoretical Chemistry Institute, University of Wisconsin-Madison, Madison, WI, United States.
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24
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Maeda Y, Fang J, Ikezoe Y, Pike DH, Nanda V, Matsui H. Molecular Self-Assembly Strategy for Generating Catalytic Hybrid Polypeptides. PLoS One 2016; 11:e0153700. [PMID: 27116246 PMCID: PMC4846159 DOI: 10.1371/journal.pone.0153700] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2015] [Accepted: 04/03/2016] [Indexed: 12/13/2022] Open
Abstract
Recently, catalytic peptides were introduced that mimicked protease activities and showed promising selectivity of products even in organic solvents where protease cannot perform well. However, their catalytic efficiency was extremely low compared to natural enzyme counterparts presumably due to the lack of stable tertiary fold. We hypothesized that assembling these peptides along with simple hydrophobic pockets, mimicking enzyme active sites, could enhance the catalytic activity. Here we fused the sequence of catalytic peptide CP4, capable of protease and esterase-like activities, into a short amyloidogenic peptide fragment of Aβ. When the fused CP4-Aβ construct assembled into antiparallel β-sheets and amyloid fibrils, a 4.0-fold increase in the hydrolysis rate of p-nitrophenyl acetate (p-NPA) compared to neat CP4 peptide was observed. The enhanced catalytic activity of CP4-Aβ assembly could be explained both by pre-organization of a catalytically competent Ser-His-acid triad and hydrophobic stabilization of a bound substrate between the triad and p-NPA, indicating that a design strategy for self-assembled peptides is important to accomplish the desired functionality.
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Affiliation(s)
- Yoshiaki Maeda
- Department of Chemistry, Hunter College and the Graduate Center, City University of New York, New York, New York, United State of America
| | - Justin Fang
- Department of Chemistry, Hunter College and the Graduate Center, City University of New York, New York, New York, United State of America
| | - Yasuhiro Ikezoe
- Department of Chemistry, Hunter College and the Graduate Center, City University of New York, New York, New York, United State of America
| | - Douglas H. Pike
- Department of Biochemistry, Center for Advanced Biotechnology and Medicine and the Department of Biochemistry and Molecular Biology, Robert Wood Johnson Medical School, Rutgers, The State University of New Jersey, Piscataway, New Jersey, United State of America
| | - Vikas Nanda
- Department of Biochemistry, Center for Advanced Biotechnology and Medicine and the Department of Biochemistry and Molecular Biology, Robert Wood Johnson Medical School, Rutgers, The State University of New Jersey, Piscataway, New Jersey, United State of America
| | - Hiroshi Matsui
- Department of Chemistry, Hunter College and the Graduate Center, City University of New York, New York, New York, United State of America
- Department of Biochemistry, Weill Medical College of Cornell University, New York, New York, United State of America
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25
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Ulas G, Lemmin T, Wu Y, Gassner GT, DeGrado WF. Designed metalloprotein stabilizes a semiquinone radical. Nat Chem 2016; 8:354-9. [PMID: 27001731 PMCID: PMC4857601 DOI: 10.1038/nchem.2453] [Citation(s) in RCA: 66] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2015] [Accepted: 01/07/2016] [Indexed: 12/25/2022]
Abstract
Enzymes use binding energy to stabilize their substrates in high-energy states that are otherwise inaccessible at ambient temperature. Here we show that a de novo designed Zn(II) metalloprotein stabilizes a chemically reactive organic radical that is otherwise unstable in aqueous media. The protein binds tightly to and stabilizes the radical semiquinone form of 3,5-di-tert-butylcatechol. Solution NMR spectroscopy in conjunction with molecular dynamics simulations show that the substrate binds in the active site pocket where it is stabilized by metal-ligand interactions as well as by burial of its hydrophobic groups. Spectrochemical redox titrations show that the protein stabilized the semiquinone by reducing the electrochemical midpoint potential for its formation via the one-electron oxidation of the catechol by approximately 400 mV (9 kcal mol(-1)). Therefore, the inherent chemical properties of the radical were changed drastically by harnessing its binding energy to the metalloprotein. This model sets the basis for designed enzymes with radical cofactors to tackle challenging chemistry.
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Affiliation(s)
- Gözde Ulas
- Department of Pharmaceutical Chemistry, University of California – San Francisco, San Francisco, California 94158, USA
| | - Thomas Lemmin
- Department of Pharmaceutical Chemistry, University of California – San Francisco, San Francisco, California 94158, USA
| | - Yibing Wu
- Department of Pharmaceutical Chemistry, University of California – San Francisco, San Francisco, California 94158, USA
| | - George T. Gassner
- Department of Chemistry and Biochemistry, San Francisco State University, San Francisco, California 94132, USA
| | - William F. DeGrado
- Department of Pharmaceutical Chemistry, University of California – San Francisco, San Francisco, California 94158, USA
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26
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An Y, Zhu Y, Yao Y, Liu J. Is it possible to reverse aged acetylcholinesterase inhibited by organophosphorus compounds? Insight from the theoretical study. Phys Chem Chem Phys 2016; 18:9838-46. [PMID: 27000635 DOI: 10.1039/c5cp07991h] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
The main treatment for organophosphorus (OP) compound poisoning in clinics is to restore the activity of acetylcholinesterase (AChE) through oxime-induced reactivation of the phosphorylated OP-AChE adduct. It suffers from a competitive and irreversible aging reaction of the phosphorylated OP-AChE adduct, resulting in permanent inactivity of AChE. However, it was recently reported that N-methyl-2-methoxypyridinium species can act as methylating agents to methylate the methyl methane-phosphonate monoanion, in which the reaction mimics the reverse of the aging reaction of the phosphorylated OP-AChE adduct. If the aging reaction could be really reversed, the efficiency for the OP detoxification should be significantly improved, bringing up the possibility to develop an agent to reverse the aging process of the phosphorylated OP-AChE adduct. However, such a reaction with the N-methyl-2-methoxypyridinium species in the enzyme is still not reported so far. It is of great interest to know whether or not this reaction is observable in the enzyme, and more importantly, if it turns out to be not observable in the enzyme, why such a reaction proceeds quickly in aqueous solution but not in the enzyme. In the present study, we performed DFT calculations and quantum mechanical/molecular mechanical (QM/MM) calculations to reveal the fundamental mechanism for the methylation of both the methyl methane-phosphonate monoanion and the aged sarin-AChE adduct by N-methyl-2-methoxypyridinium species, respectively. The obtained results support the SN2 reaction mechanism, not the stepwise mechanism, for the methylation of the methyl methane-phosphonate monoanion by 9 reported N-methyl-2-methoxypyridinium compounds. The calculated free energy barriers are in good agreement with the experimental data. The methylation of the aged sarin-AChE adduct by one N-methyl-2-methoxypyridinium compound (labeled as compound 2) also employs the SN2 reaction mechanism with an extremely high free energy barrier of 30.4 ± 3.5 (or 26.6) kcal mol(-1), implying that this reaction in the enzyme hardly occurs. Our results clearly show that compound 2 forms a strong π-π stacking interaction with the aromatic ring of the W86 residue of AChE, making itself unable to approach sarin for the reverse of the aging process. On the basis of the structure and mechanism, several possible strategies have been suggested for designing methylating agents with higher activity against the aged sarin-AChE adduct.
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Affiliation(s)
- Yun An
- Institute of Theoretical and Simulational Chemistry, Academy of Fundamental and Interdisciplinary Science, Harbin Institute of Technology, 2 Yikuang Street, Harbin, 150080, P. R. China.
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27
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Abstract
Human DNA methyltransferase 1 (DNMT1) maintains the epigenetic state of DNA by replicating CpG methylation signatures from parent to daughter strands, producing heritable methylation patterns through cell divisions. The proposed catalytic mechanism of DNMT1 involves nucleophilic attack of Cys(1226) to cytosine (Cyt) C6, methyl transfer from S-adenosyl-l-methionine (SAM) to Cyt C5, and proton abstraction from C5 to form methylated CpG in DNA. Here, we report the subangstrom geometric and electrostatic structure of the major transition state (TS) of the reaction catalyzed by human DNMT1. Experimental kinetic isotope effects were used to guide quantum mechanical calculations to solve the TS structure. Methyl transfer occurs after Cys(1226) attack to Cyt C6, and the methyl transfer step is chemically rate-limiting for DNMT1. Electrostatic potential maps were compared for the TS and ground states, providing the electronic basis for interactions between the protein and reactants at the TS. Understanding the TS of DNMT1 demonstrates the possibility of using similar analysis to gain subangstrom geometric insight into the complex reactions of epigenetic modifications.
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Affiliation(s)
- Quan Du
- Department of Biochemistry, Albert Einstein College of Medicine, Bronx, NY 10461
| | - Zhen Wang
- Department of Biochemistry, Albert Einstein College of Medicine, Bronx, NY 10461
| | - Vern L Schramm
- Department of Biochemistry, Albert Einstein College of Medicine, Bronx, NY 10461
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28
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Sandhya S, Mudgal R, Kumar G, Sowdhamini R, Srinivasan N. Protein sequence design and its applications. Curr Opin Struct Biol 2016; 37:71-80. [PMID: 26773478 DOI: 10.1016/j.sbi.2015.12.004] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2015] [Revised: 12/07/2015] [Accepted: 12/15/2015] [Indexed: 01/14/2023]
Abstract
Design of proteins has far-reaching potentials in diverse areas that span repurposing of the protein scaffold for reactions and substrates that they were not naturally meant for, to catching a glimpse of the ephemeral proteins that nature might have sampled during evolution. These non-natural proteins, either in synthesized or virtual form have opened the scope for the design of entities that not only rival their natural counterparts but also offer a chance to visualize the protein space continuum that might help to relate proteins and understand their associations. Here, we review the recent advances in protein engineering and design, in multiple areas, with a view to drawing attention to their future potential.
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Affiliation(s)
- Sankaran Sandhya
- Molecular Biophysics Unit, Indian Institute of Science, Bangalore 560 012, India
| | - Richa Mudgal
- Molecular Biophysics Unit, Indian Institute of Science, Bangalore 560 012, India; IISc Mathematics Initiative, Indian Institute of Science, Bangalore 560 012, India
| | - Gayatri Kumar
- Molecular Biophysics Unit, Indian Institute of Science, Bangalore 560 012, India
| | - Ramanathan Sowdhamini
- National Centre for Biological Sciences-TIFR, UAS-GKVK Campus, Bangalore 560065, India
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Hu C, Wang J. Method for Enzyme Design with Genetically Encoded Unnatural Amino Acids. Methods Enzymol 2016; 580:109-33. [DOI: 10.1016/bs.mie.2016.06.005] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/07/2023]
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Pottel J, Moitessier N. Single-Point Mutation with a Rotamer Library Toolkit: Toward Protein Engineering. J Chem Inf Model 2015; 55:2657-71. [PMID: 26623941 DOI: 10.1021/acs.jcim.5b00525] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Protein engineers have long been hard at work to harness biocatalysts as a natural source of regio-, stereo-, and chemoselectivity in order to carry out chemistry (reactions and/or substrates) not previously achieved with these enzymes. The extreme labor demands and exponential number of mutation combinations have induced computational advances in this domain. The first step in our virtual approach is to predict the correct conformations upon mutation of residues (i.e., rebuilding side chains). For this purpose, we opted for a combination of molecular mechanics and statistical data. In this work, we have developed automated computational tools to extract protein structural information and created conformational libraries for each amino acid dependent on a variable number of parameters (e.g., resolution, flexibility, secondary structure). We have also developed the necessary tool to apply the mutation and optimize the conformation accordingly. For side-chain conformation prediction, we obtained overall average root-mean-square deviations (RMSDs) of 0.91 and 1.01 Å for the 18 flexible natural amino acids within two distinct sets of over 3000 and 1500 side-chain residues, respectively. The commonly used dihedral angle differences were also evaluated and performed worse than the state of the art. These two metrics are also compared. Furthermore, we generated a family-specific library for kinases that produced an average 2% lower RMSD upon side-chain reconstruction and a residue-specific library that yielded a 17% improvement. Ultimately, since our protein engineering outlook involves using our docking software, Fitted/Impacts, we applied our mutation protocol to a benchmarked data set for self- and cross-docking. Our side-chain reconstruction does not hinder our docking software, demonstrating differences in pose prediction accuracy of approximately 2% (RMSD cutoff metric) for a set of over 200 protein/ligand structures. Similarly, when docking to a set of over 100 kinases, side-chain reconstruction (using both general and biased conformation libraries) had minimal detriment to the docking accuracy.
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Affiliation(s)
- Joshua Pottel
- Department of Chemistry, McGill University , 801 Sherbrooke Street West, Montreal, QC, Canada H3A 0B8
| | - Nicolas Moitessier
- Department of Chemistry, McGill University , 801 Sherbrooke Street West, Montreal, QC, Canada H3A 0B8
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Hilaire MR, Abaskharon RM, Gai F. Biomolecular Crowding Arising from Small Molecules, Molecular Constraints, Surface Packing, and Nano-Confinement. J Phys Chem Lett 2015; 6:2546-53. [PMID: 26266732 PMCID: PMC4610718 DOI: 10.1021/acs.jpclett.5b00957] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/07/2023]
Abstract
The effect of macromolecular crowding on the structure, dynamics, and reactivity of biomolecules is well established and the relevant research has been extensively reviewed. Herein, we focus our discussion on crowding effects arising from small cosolvent molecules and densely packed surface conditions. In addition, we highlight recent efforts that capitalize on the excluded volume effect for various tailored biochemical and biophysical applications. Specifically, we discuss how a targeted increase in local mass density can be exploited to gain insight into the folding dynamics of the protein of interest and how confinement via reverse micelles can be used to study a range of biophysical questions, from protein hydration dynamics to amyloid formation.
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Affiliation(s)
| | | | - Feng Gai
- To whom correspondence should be addressed; ; Phone: 215-573-6256; Fax: 215-573-2112
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Elward JM, Rinderspacher BC. Smooth heuristic optimization on a complex chemical subspace. Phys Chem Chem Phys 2015; 17:24322-35. [DOI: 10.1039/c5cp02177d] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
In the present work, several heuristic reordering algorithms for deterministic optimization on a combinatorial chemical compound space are evaluated for performance and efficiency.
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