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Budiarta M, Streit M, Beliu G. Site-specific protein labeling strategies for super-resolution microscopy. Curr Opin Chem Biol 2024; 80:102445. [PMID: 38490137 DOI: 10.1016/j.cbpa.2024.102445] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2024] [Revised: 02/28/2024] [Accepted: 02/28/2024] [Indexed: 03/17/2024]
Abstract
Super-resolution microscopy (SRM) has transformed our understanding of proteins' subcellular organization and revealed cellular details down to nanometers, far beyond conventional microscopy. While localization precision is independent of the number of fluorophores attached to a biomolecule, labeling density is a decisive factor for resolving complex biological structures. The average distance between adjacent fluorophores should be less than half the desired spatial resolution for optimal clarity. While this was not a major limitation in recent decades, the success of modern microscopy approaching molecular resolution down to the single-digit nanometer range will depend heavily on advancements in fluorescence labeling. This review highlights recent advances and challenges in labeling strategies for SRM, focusing on site-specific labeling technologies. These advancements are crucial for improving SRM precision and expanding our understanding of molecular interactions.
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Affiliation(s)
- Made Budiarta
- Rudolf Virchow Center, Research Center for Integrative and Translational Bioimaging, University of Würzburg, 97080 Würzburg, Germany
| | - Marcel Streit
- Rudolf Virchow Center, Research Center for Integrative and Translational Bioimaging, University of Würzburg, 97080 Würzburg, Germany
| | - Gerti Beliu
- Rudolf Virchow Center, Research Center for Integrative and Translational Bioimaging, University of Würzburg, 97080 Würzburg, Germany; Interdisciplinary Institute for Neuroscience, University of Bordeaux, CNRS, UMR 5297, 33076 Bordeaux, France.
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2
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Kaushik V, Chadda R, Kuppa S, Pokhrel N, Vayyeti A, Grady S, Arnatt C, Antony E. Fluorescent human RPA to track assembly dynamics on DNA. Methods 2024; 223:95-105. [PMID: 38301751 PMCID: PMC10923064 DOI: 10.1016/j.ymeth.2024.01.019] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2023] [Revised: 01/25/2024] [Accepted: 01/29/2024] [Indexed: 02/03/2024] Open
Abstract
DNA metabolic processes including replication, repair, recombination, and telomere maintenance occur on single-stranded DNA (ssDNA). In each of these complex processes, dozens of proteins function together on the ssDNA template. However, when double-stranded DNA is unwound, the transiently open ssDNA is protected and coated by the high affinity heterotrimeric ssDNA binding Replication Protein A (RPA). Almost all downstream DNA processes must first remodel/remove RPA or function alongside to access the ssDNA occluded under RPA. Formation of RPA-ssDNA complexes trigger the DNA damage checkpoint response and is a key step in activating most DNA repair and recombination pathways. Thus, in addition to protecting the exposed ssDNA, RPA functions as a gatekeeper to define functional specificity in DNA maintenance and genomic integrity. RPA achieves functional dexterity through a multi-domain architecture utilizing several DNA binding and protein-interaction domains connected by flexible linkers. This flexible and modular architecture enables RPA to adopt a myriad of configurations tailored for specific DNA metabolic roles. To experimentally capture the dynamics of the domains of RPA upon binding to ssDNA and interacting proteins we here describe the generation of active site-specific fluorescent versions of human RPA (RPA) using 4-azido-L-phenylalanine (4AZP) incorporation and click chemistry. This approach can also be applied to site-specific modifications of other multi-domain proteins. Fluorescence-enhancement through non-canonical amino acids (FEncAA) and Förster Resonance Energy Transfer (FRET) assays for measuring dynamics of RPA on DNA are also described. The fluorescent human RPA described here will enable high-resolution structure-function analysis of RPA-ssDNA interactions.
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Affiliation(s)
- Vikas Kaushik
- Department of Biochemistry and Molecular Biology, St. Louis University School of Medicine, St. Louis, MO 63104, USA
| | - Rahul Chadda
- Department of Biochemistry and Molecular Biology, St. Louis University School of Medicine, St. Louis, MO 63104, USA
| | - Sahiti Kuppa
- Department of Biochemistry and Molecular Biology, St. Louis University School of Medicine, St. Louis, MO 63104, USA
| | - Nilisha Pokhrel
- Department of Biological Sciences, Marquette University, Milwaukee, WI 53233, USA
| | - Abhinav Vayyeti
- Department of Biochemistry and Molecular Biology, St. Louis University School of Medicine, St. Louis, MO 63104, USA
| | - Scott Grady
- Department of Chemistry, St. Louis University, St. Louis, MO 63103, USA
| | - Chris Arnatt
- Department of Chemistry, St. Louis University, St. Louis, MO 63103, USA
| | - Edwin Antony
- Department of Biochemistry and Molecular Biology, St. Louis University School of Medicine, St. Louis, MO 63104, USA.
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Natter Perdiguero A, Deliz Liang A. Practical Approaches to Genetic Code Expansion with Aminoacyl-tRNA Synthetase/tRNA Pairs. Chimia (Aarau) 2024; 78:22-31. [PMID: 38430060 DOI: 10.2533/chimia.2024.22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2023] [Accepted: 11/23/2023] [Indexed: 03/03/2024] Open
Abstract
Genetic code expansion (GCE) can enable the site-selective incorporation of non-canonical amino acids (ncAAs) into proteins. GCE has advanced tremendously in the last decade and can be used to create biorthogonal handles, monitor and control proteins inside cells, study post-translational modifications, and engineer new protein functions. Since establishing our laboratory, our research has focused on applications of GCE in protein and enzyme engineering using aminoacyl-tRNA synthetase/tRNA (aaRS/tRNA) pairs. This topic has been reviewed extensively, leaving little doubt that GCE is a powerful tool for engineering proteins and enzymes. Therefore, for this young faculty issue, we wanted to provide a more technical look into the methods we use and the challenges we think about in our laboratory. Since starting the laboratory, we have successfully engineered over a dozen novel aaRS/tRNA pairs tailored for various GCE applications. However, we acknowledge that the field can pose challenges even for experts. Thus, herein, we provide a review of methodologies in ncAA incorporation with some practical commentary and a focus on challenges, emerging solutions, and exciting developments.
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Lino BR, Van Deventer JA. Genome-Wide Screen for Enhanced Noncanonical Amino Acid Incorporation in Yeast. Methods Mol Biol 2024; 2760:219-251. [PMID: 38468092 DOI: 10.1007/978-1-0716-3658-9_14] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/13/2024]
Abstract
Expanding the genetic code beyond the 20 canonical amino acids enables access to a wide range of chemical functionality that is inaccessible within conventionally biosynthesized proteins. The vast majority of efforts to expand the genetic code have focused on the orthogonal translation systems required to achieve the genetically encoded addition of noncanonical amino acids (ncAAs) into proteins. There remain tremendous opportunities for identifying genetic and genomic factors that enhance ncAA incorporation. Here we describe genome-wide screening strategies to identify factors that enable more efficient addition of ncAAs to biosynthesized proteins. These unbiased screens can reveal previously unknown genes or mutations that can enhance ncAA incorporation and deepen our understanding of the translation apparatus.
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Affiliation(s)
- Briana R Lino
- Chemical and Biological Engineering Department, Tufts University, Medford, MA, USA
| | - James A Van Deventer
- Chemical and Biological Engineering Department, Tufts University, Medford, MA, USA.
- Biomedical Engineering Department, Tufts University, Medford, MA, USA.
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5
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Gao T, Guo J, Niu W. Genetic Code Expansion in Pseudomonas putida KT2440. Methods Mol Biol 2024; 2760:209-217. [PMID: 38468091 DOI: 10.1007/978-1-0716-3658-9_13] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/13/2024]
Abstract
Emerging microorganism Pseudomonas putida KT2440 is utilized for the synthesis of biobased chemicals from renewable feedstocks and for bioremediation. However, the methods for analyzing, engineering, and regulating the biosynthetic enzymes and protein complexes in this organism remain underdeveloped.Such attempts can be advanced by the genetic code expansion-enabled incorporation of noncanonical amino acids (ncAAs) into proteins, which also enables further controls over the strain's biological processes. Here, we give a step-by-step account of the incorporation of two ncAAs into any protein of interest (POI) in response to a UAG stop codon by two commonly used orthogonal archaeal tRNA synthetase and tRNA pairs. Using superfolder green fluorescent protein (sfGFP) as an example, this method lays down a solid foundation for future work to study and enhance the biological functions of KT2440.
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Affiliation(s)
- Tianyu Gao
- Department of Chemistry, University of Nebraska-Lincoln, Lincoln, NE, USA
| | - Jiantao Guo
- Department of Chemistry, University of Nebraska-Lincoln, Lincoln, NE, USA.
- The Nebraska Center for Integrated Biomolecular Communication (NCIBC), University of Nebraska-Lincoln, Lincoln, NE, USA.
| | - Wei Niu
- The Nebraska Center for Integrated Biomolecular Communication (NCIBC), University of Nebraska-Lincoln, Lincoln, NE, USA.
- Department of Chemical & Biomolecular Engineering, University of Nebraska-Lincoln, Lincoln, NE, USA.
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Liu K, Jiang L, Ma S, Song Z, Wang L, Zhang Q, Xu R, Yang L, Wu J, Yu H. An evolved pyrrolysyl-tRNA synthetase with polysubstrate specificity expands the toolbox for engineering enzymes with incorporation of noncanonical amino acids. BIORESOUR BIOPROCESS 2023; 10:92. [PMID: 38647798 PMCID: PMC10991234 DOI: 10.1186/s40643-023-00712-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2023] [Accepted: 12/03/2023] [Indexed: 04/25/2024] Open
Abstract
Aminoacyl-tRNA synthetase (aaRS) is a core component for genetic code expansion (GCE), a powerful technique that enables the incorporation of noncanonical amino acids (ncAAs) into a protein. The aaRS with polyspecificity can be exploited in incorporating additional ncAAs into a protein without the evolution of new, orthogonal aaRS/tRNA pair, which hence provides a useful tool for probing the enzyme mechanism or expanding protein function. A variant (N346A/C348A) of pyrrolysyl-tRNA synthetase from Methanosarcina mazei (MmPylRS) exhibited a wide substrate scope of accepting over 40 phenylalanine derivatives. However, for most of the substrates, the incorporation efficiency was low. Here, a MbPylRS (N311A/C313A) variant was constructed that showed higher ncAA incorporation efficiency than its homologous MmPylRS (N346A/C348A). Next, N-terminal of MbPylRS (N311A/C313A) was engineered by a greedy combination of single variants identified previously, resulting in an IPE (N311A/C313A/V31I/T56P/A100E) variant with significantly improved activity against various ncAAs. Activity of IPE was then tested toward 43 novel ncAAs, and 16 of them were identified to be accepted by the variant. The variant hence could incorporate nearly 60 ncAAs in total into proteins. With the utility of this variant, eight various ncAAs were then incorporated into a lanthanide-dependent alcohol dehydrogenase PedH. Incorporation of phenyllactic acid improved the catalytic efficiency of PedH toward methanol by 1.8-fold, indicating the role of modifying protein main chain in enzyme engineering. Incorporation of O-tert-Butyl-L-tyrosine modified the enantioselectivity of PedH by influencing the interactions between substrate and protein. Enzymatic characterization and molecular dynamics simulations revealed the mechanism of ncAAs affecting PedH catalysis. This study provides a PylRS variant with high activity and substrate promiscuity, which increases the utility of GCE in enzyme mechanism illustration and engineering.
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Affiliation(s)
- Ke Liu
- Institute of Bioengineering, College of Chemical and Biological Engineering, Zhejiang University, Hangzhou, 310027, Zhejiang, China
| | - Ling Jiang
- Institute of Bioengineering, College of Chemical and Biological Engineering, Zhejiang University, Hangzhou, 310027, Zhejiang, China
- ZJU-Hangzhou Global Scientific and Technological Innovation Centre, Hangzhou, 311200, Zhejiang, China
| | - Shuang Ma
- Institute of Bioengineering, College of Chemical and Biological Engineering, Zhejiang University, Hangzhou, 310027, Zhejiang, China
| | - Zhongdi Song
- Key Laboratory of Pollution Exposure and Health Intervention of Zhejiang Province, Interdisciplinary Research Academy, Zhejiang Shuren University, Hangzhou, 310015, Zhejiang, China.
| | - Lun Wang
- Institute of Bioengineering, College of Chemical and Biological Engineering, Zhejiang University, Hangzhou, 310027, Zhejiang, China
- ZJU-Hangzhou Global Scientific and Technological Innovation Centre, Hangzhou, 311200, Zhejiang, China
| | - Qunfeng Zhang
- Institute of Bioengineering, College of Chemical and Biological Engineering, Zhejiang University, Hangzhou, 310027, Zhejiang, China
| | - Renhao Xu
- Hangzhou 14th Middle School, Hangzhou, 310006, Zhejiang, China
| | - Lirong Yang
- Institute of Bioengineering, College of Chemical and Biological Engineering, Zhejiang University, Hangzhou, 310027, Zhejiang, China
- ZJU-Hangzhou Global Scientific and Technological Innovation Centre, Hangzhou, 311200, Zhejiang, China
| | - Jianping Wu
- Institute of Bioengineering, College of Chemical and Biological Engineering, Zhejiang University, Hangzhou, 310027, Zhejiang, China
- ZJU-Hangzhou Global Scientific and Technological Innovation Centre, Hangzhou, 311200, Zhejiang, China
| | - Haoran Yu
- Institute of Bioengineering, College of Chemical and Biological Engineering, Zhejiang University, Hangzhou, 310027, Zhejiang, China.
- ZJU-Hangzhou Global Scientific and Technological Innovation Centre, Hangzhou, 311200, Zhejiang, China.
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Meineke B, Heimgärtner J, Caridha R, Block MF, Kimler KJ, Pires MF, Landreh M, Elsässer SJ. Dual stop codon suppression in mammalian cells with genomically integrated genetic code expansion machinery. Cell Rep Methods 2023; 3:100626. [PMID: 37935196 PMCID: PMC10694491 DOI: 10.1016/j.crmeth.2023.100626] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/22/2023] [Revised: 08/22/2023] [Accepted: 10/12/2023] [Indexed: 11/09/2023]
Abstract
Stop codon suppression using dedicated tRNA/aminoacyl-tRNA synthetase (aaRS) pairs allows for genetically encoded, site-specific incorporation of non-canonical amino acids (ncAAs) as chemical handles for protein labeling and modification. Here, we demonstrate that piggyBac-mediated genomic integration of archaeal pyrrolysine tRNA (tRNAPyl)/pyrrolysyl-tRNA synthetase (PylRS) or bacterial tRNA/aaRS pairs, using a modular plasmid design with multi-copy tRNA arrays, allows for homogeneous and efficient genetically encoded ncAA incorporation in diverse mammalian cell lines. We assess opportunities and limitations of using ncAAs for fluorescent labeling applications in stable cell lines. We explore suppression of ochre and opal stop codons and finally incorporate two distinct ncAAs with mutually orthogonal click chemistries for site-specific, dual-fluorophore labeling of a cell surface receptor on live mammalian cells.
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Affiliation(s)
- Birthe Meineke
- Science for Life Laboratory, Karolinska Institutet, Department of Medical Biochemistry and Biophysics, Division of Genome Biology, 17165 Stockholm, Sweden; Ming Wai Lau Centre for Reparative Medicine, Stockholm Node, Karolinska Institutet, 17165 Stockholm, Sweden.
| | - Johannes Heimgärtner
- Science for Life Laboratory, Karolinska Institutet, Department of Medical Biochemistry and Biophysics, Division of Genome Biology, 17165 Stockholm, Sweden; Ming Wai Lau Centre for Reparative Medicine, Stockholm Node, Karolinska Institutet, 17165 Stockholm, Sweden
| | - Rozina Caridha
- Science for Life Laboratory, Karolinska Institutet, Department of Medical Biochemistry and Biophysics, Division of Genome Biology, 17165 Stockholm, Sweden; Ming Wai Lau Centre for Reparative Medicine, Stockholm Node, Karolinska Institutet, 17165 Stockholm, Sweden
| | - Matthias F Block
- Science for Life Laboratory, Karolinska Institutet, Department of Medical Biochemistry and Biophysics, Division of Genome Biology, 17165 Stockholm, Sweden
| | - Kyle J Kimler
- Science for Life Laboratory, Karolinska Institutet, Department of Medical Biochemistry and Biophysics, Division of Genome Biology, 17165 Stockholm, Sweden
| | - Maria F Pires
- Science for Life Laboratory, Karolinska Institutet, Department of Medical Biochemistry and Biophysics, Division of Genome Biology, 17165 Stockholm, Sweden
| | - Michael Landreh
- Department of Microbiology, Tumor and Cell Biology, Science for Life Laboratory, Karolinska Institutet, 17165 Stockholm, Sweden
| | - Simon J Elsässer
- Science for Life Laboratory, Karolinska Institutet, Department of Medical Biochemistry and Biophysics, Division of Genome Biology, 17165 Stockholm, Sweden; Ming Wai Lau Centre for Reparative Medicine, Stockholm Node, Karolinska Institutet, 17165 Stockholm, Sweden.
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Zhu P, Mehl RA, Cooley RB. Biosynthesis and Genetic Encoding of Non-hydrolyzable Phosphoserine into Recombinant Proteins in Escherichia coli. Bio Protoc 2023; 13:e4861. [PMID: 37969748 PMCID: PMC10632156 DOI: 10.21769/bioprotoc.4861] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2023] [Revised: 08/28/2023] [Accepted: 08/29/2023] [Indexed: 11/17/2023] Open
Abstract
While site-specific translational encoding of phosphoserine (pSer) into proteins in Escherichia coli via genetic code expansion (GCE) technologies has transformed our ability to study phospho-protein structure and function, recombinant phospho-proteins can be dephosphorylated during expression/purification, and their exposure to cellular-like environments such as cell lysates results in rapid reversion back to the non-phosphorylated form. To help overcome these challenges, we developed an efficient and scalable E. coli GCE expression system enabling site-specific incorporation of a non-hydrolyzable phosphoserine (nhpSer) mimic into proteins of interest. This nhpSer mimic, with the γ-oxygen of phosphoserine replaced by a methylene (CH2) group, is impervious to hydrolysis and recapitulates phosphoserine function even when phosphomimetics aspartate and glutamate do not. Key to this expression system is the co-expression of a Streptomyces biosynthetic pathway that converts the central metabolite phosphoenolpyruvate into non-hydrolyzable phosphoserine (nhpSer) amino acid, which provides a > 40-fold improvement in expression yields compared to media supplementation by increasing bioavailability of nhpSer and enables scalability of expressions. This "PermaPhos" expression system uses the E. coli BL21(DE3) ΔserC strain and three plasmids that express (i) the protein of interest, (ii) the GCE machinery for translational installation of nhpSer at UAG amber stop codons, and (iii) the Streptomyces nhpSer biosynthetic pathway. Successful expression requires efficient transformation of all three plasmids simultaneously into the expression host, and IPTG is used to induce expression of all components. Permanently phosphorylated proteins made in E. coli are particularly useful for discovering phosphorylation-dependent protein-protein interaction networks from cell lysates or transfected cells. Key features • Protocol builds on the nhpSer GCE system by Rogerson et al. (2015), but with a > 40-fold improvement in yields enabled by the nhpSer biosynthetic pathway. • Protein expression uses standard Terrific Broth (TB) media and requires three days to complete. • C-terminal purification tags on target protein are recommended to avoid co-purification of prematurely truncated protein with full-length nhpSer-containing protein. • Phos-tag gel electrophoresis provides a convenient method to confirm accurate nhpSer encoding, as it can distinguish between non-phosphorylated, pSer- and nhpSer-containing variants.
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Affiliation(s)
- Phillip Zhu
- Department of Biochemistry and Biophysics, Oregon State University, 2011 Agricultural and Life Sciences, Corvallis, OR, USA
- GCE4All Research Center, Oregon State University, 2011 Agricultural and Life Sciences, Corvallis, OR, USA
| | - Ryan A. Mehl
- Department of Biochemistry and Biophysics, Oregon State University, 2011 Agricultural and Life Sciences, Corvallis, OR, USA
- GCE4All Research Center, Oregon State University, 2011 Agricultural and Life Sciences, Corvallis, OR, USA
| | - Richard B. Cooley
- Department of Biochemistry and Biophysics, Oregon State University, 2011 Agricultural and Life Sciences, Corvallis, OR, USA
- GCE4All Research Center, Oregon State University, 2011 Agricultural and Life Sciences, Corvallis, OR, USA
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Ali S, Ma G, Zhou Y. Shedding light on ORAI1 channel with genetic code expansion. Cell Calcium 2023; 113:102755. [PMID: 37196487 PMCID: PMC10484295 DOI: 10.1016/j.ceca.2023.102755] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2023] [Accepted: 05/09/2023] [Indexed: 05/19/2023]
Abstract
Genetic code expansion technology has been widely applied to control protein activity and biological systems by taking advantage of an amber stop codon suppressor tRNA and orthogonal aminoacyl-tRNA synthetase pair. With this chemical biology approach, Maltan et al. incorporated photocrosslinking unnatural amino acids (UAAs) into the transmembrane domains of ORAI1 to enable UV light-inducible calcium influx across the plasma membrane, mechanistic interrogation of the calcium release-activated calcium (CRAC) channel at the single amino acid level, and remote control of downstream calcium-modulated signaling in mammalian cells.
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Affiliation(s)
- Sher Ali
- Center for Translational Cancer Research, Institute of Biosciences and Technology, Texas A&M University, Houston, TX, 77030, United States of America
| | - Guolin Ma
- Center for Translational Cancer Research, Institute of Biosciences and Technology, Texas A&M University, Houston, TX, 77030, United States of America; Department of Translational Medical Sciences, School of Medicine, Texas A&M University, Houston, TX, 77030, United States of America.
| | - Yubin Zhou
- Center for Translational Cancer Research, Institute of Biosciences and Technology, Texas A&M University, Houston, TX, 77030, United States of America; Department of Translational Medical Sciences, School of Medicine, Texas A&M University, Houston, TX, 77030, United States of America.
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Giger S, Buller R. Advances in Noncanonical Amino Acid Incorporation for Enzyme Engineering Applications. Chimia (Aarau) 2023; 77:395-402. [PMID: 38047779 DOI: 10.2533/chimia.2023.395] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2023] [Accepted: 05/17/2023] [Indexed: 12/05/2023] Open
Abstract
Incorporation of noncanonical amino acids (ncAAs) via genetic code expansion (GCE) opens up new possibilities for chemical biology. The technology has led to the development of novel xenobiotic enzymes with tailored properties which can serve as entry points into a multitude of applications, including protein conjugation, immobilization, or labeling. In this review, we discuss recent progress in the use of GCE to create biocatalysts possessing reaction repertoires that lie beyond what is achievable with canonical amino acids (cAAs). Furthermore, we highlight how GCE enables to gain mechanistic insights into protein function by the incorporation of judiciously selected ncAAs. As the amino acid alphabet continues to grow and improved tools for ncAA incorporation are being developed, we anticipate the creation of additional powerful biological catalysts for synthetic application which merge the chemical versatility of anthropogenic building blocks with the exquisite selectivities of enzymes.
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Affiliation(s)
- Sandro Giger
- Zurich University of Applied Sciences, School of Life Sciences and Facility Management, Institute of Chemistry and Biotechnology, Einsiedlerstrasse 31, CH-8820 Wädenswil.
- Vienna University of Technology, Faculty of Technical Chemistry, Institute of Applied Synthetic Chemistry, Getreidemarkt 9, 1060 Vienna, Austria
| | - Rebecca Buller
- Zurich University of Applied Sciences, School of Life Sciences and Facility Management, Institute of Chemistry and Biotechnology, Einsiedlerstrasse 31, CH-8820 Wädenswil,.
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11
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Cronin CN. Optimization of genetic code expansion in the baculovirus expression vector system (BEVS). Protein Expr Purif 2023:106314. [PMID: 37269916 DOI: 10.1016/j.pep.2023.106314] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2023] [Revised: 05/30/2023] [Accepted: 06/01/2023] [Indexed: 06/05/2023]
Abstract
The production of recombinant proteins containing unnatural amino acids, commonly known as genetic code expansion (GCE), represents a breakthrough in protein engineering that allows for the creation of proteins having novel designed properties. The naturally occurring orthogonal pyrrolysine tRNA/aminoacyl-tRNApyl synthetase pair (tRNApyl/PylRS) found in Methanosarcinaceae species has provided a rich platform for protein engineers to build a library of amino acid derivatives suitable for the introduction of novel chemical functionalities. While reports of the production of such recombinant proteins utilizing the tRNApyl/PylRS pair, or mutants thereof, is commonplace in Escherichia coli and mammalian cell expression systems, there has only been a single such report of GCE in the other stalwart of recombinant protein production, the baculovirus expression vector system (BEVS). However, that report formulates protein production within the designs of the MultiBac expression system [1]. The current study frames protein production within the strategies of the more commonplace Bac-to-Bac system of recombinant baculovirus production, via the development of novel baculovirus transfer vectors that harbor the tRNApyl/PylRS pair. The production of recombinant proteins harboring an unnatural amino acid(s) was examined using both an in cis and an in trans arrangement of the tRNApyl/PylRS pair relative to the target protein ORF i.e. the latter resides, respectively, on either the same vector as the tRNApyl/PylRS pair, or on a separate vector and deployed in a viral co-infection experiment. Aspects of the transfer vector designs and the viral infection conditions were investigated.
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Affiliation(s)
- Ciarán N Cronin
- Structural Biology and Protein Sciences, Pfizer Global Research, Development and Medical, 10770 Science Center Drive, La Jolla, CA, USA.
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Wu XY, Li MY, Yang SJ, Jiang J, Ying YL, Chen PR, Long YT. Controlled Genetic Encoding of Unnatural Amino Acid in Protein Nanopore. Angew Chem Int Ed Engl 2023:e202300582. [PMID: 37195576 DOI: 10.1002/anie.202300582] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2023] [Revised: 05/09/2023] [Accepted: 05/15/2023] [Indexed: 05/18/2023]
Abstract
Conventional protein engineering methods for modifying protein nanopore are typically limited to 20 natural amino acids, which restricts the diversity of nanopore in structure and function. To enrich the chemical environment inside the nanopore, we employed the genetic code expansion (GCE) technique to site-specifically incorporate unnatural amino acid (UAA) into the sensing region of aerolysin nanopore. This approach leveraged the efficient pyrrolysine-based aminoacyl-tRNA synthetase-tRNA pair for a high yield of pore-forming protein. Both molecular dynamics (MD) simulations and single-molecule sensing experiments demonstrated that the conformation of UAA residues provided a favorable geometric orientation for the interactions of target molecules and the pore. This reasonably designed chemical environment enabled the direct discrimination of multiple peptides containing hydrophobic amino acids. Our work provides a new framework to endow unique sensing properties to nanopore that are difficult to achieve using classical protein engineering approaches.
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Affiliation(s)
- Xue-Yuan Wu
- Nanjing University, State Key Laboratory of Analytical Chemistry for Life Science, School of Chemistry and Chemical Engineering, CHINA
| | - Meng-Yin Li
- Nanjing University, State Key Laboratory of Analytical Chemistry for Life Science, School of Chemistry and Chemical Engineering, CHINA
| | - Shao-Jun Yang
- Peking University, Synthetic and Functional Biomolecules Center, Beijing National Laboratory for Molecular Sciences, Key Laboratory of Bioorganic Chemistry and Molecular Engineering of Ministry of Education, College of Chemistry and Molecular Engineering, CHINA
| | - Jie Jiang
- Nanjing University, State Key Laboratory of Analytical Chemistry for Life Science, School of Chemistry and Chemical Engineering, CHINA
| | - Yi-Lun Ying
- Nanjing University, School of Chemistry and Chemical Engineering, 163 Xianlin Avenu, 210023, Nanjing, CHINA
| | - Peng R Chen
- Peking University, Synthetic and Functional Biomolecules Center, Beijing National Laboratory for Molecular Sciences, Key Laboratory of Bioorganic Chemistry and Molecular Engineering of Ministry of Education, College of Chemistry and Molecular Engineering, Peking-Tsinghua Center for Life Sciences, CHINA
| | - Yi-Tao Long
- Nanjing University, State Key Laboratory of Analytical Chemistry for Life Science, School of Chemistry and Chemical Engineering, CHINA
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13
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Liu J, Yang B, Wang L. Residue selective crosslinking of proteins through photoactivatable or proximity-enabled reactivity. Curr Opin Chem Biol 2023; 74:102285. [PMID: 36913752 DOI: 10.1016/j.cbpa.2023.102285] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2022] [Revised: 02/08/2023] [Accepted: 02/12/2023] [Indexed: 03/13/2023]
Abstract
Photo- and chemical crosslinking of proteins have offered various avenues for studying protein structure and protein interactions with biomolecules. Conventional photoactivatable groups generally lack reaction selectivity toward amino acid residues. New photoactivatable groups reacting with selected residues have emerged recently, increasing crosslinking efficiency and facilitating crosslink identification. Traditional chemical crosslinking usually employs highly reactive functional groups, while recent advance has developed latent reactive groups with reactivity triggered by proximity, which reduce spurious crosslinks and improve biocompatibility. The employment of these residue selective chemical functional groups, activated by light or proximity, in small molecule crosslinkers and in genetically encoded unnatural amino acids is summarized. Together with new software development in identifying protein crosslinks, residue selective crosslinking has enhanced the research of elusive protein-protein interactions in vitro, in cell lysate, and in live cells. Residue selective crosslinking is expected to expand to other methods for the investigation of various protein-biomolecule interactions.
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14
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Shade O, Ryan A, Deiters A. Targeted protein degradation through light-activated E3 ligase recruitment. Methods Enzymol 2023; 681:265-286. [PMID: 36764761 DOI: 10.1016/bs.mie.2022.10.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Optical control of protein function through proteasomal degradation benefits from the noninvasive nature and spatiotemporal precision of light as a trigger. In this chapter, light activation of protein degradation with an optically controlled degron, termed optoDeg, is discussed. This method utilizes genetic code expansion to insert a photocaged analog of lysine at the N-terminal position of a protein of interest for spatial and temporal control of the N-end pathway, inducing proteasomal degradation. Methods for the use of optoDeg for degradation of the fluorescent reporter EGFP and the kinase MEK1 are described. The system is fast, with complete degradation of proteins within minutes following irradiation, and highly specific, with genetically directed introduction of the light-activated degron.
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Affiliation(s)
- Olivia Shade
- Department of Chemistry, University of Pittsburgh, Pittsburgh, PA, United States
| | - Amy Ryan
- Department of Chemistry, University of Pittsburgh, Pittsburgh, PA, United States
| | - Alexander Deiters
- Department of Chemistry, University of Pittsburgh, Pittsburgh, PA, United States.
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15
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Chaudhari AS, Chatterjee A, Domingos CAO, Andrikopoulos PC, Liu Y, Andersson I, Schneider B, Lórenz-Fonfría VA, Fuertes G. Genetically encoded non-canonical amino acids reveal asynchronous dark reversion of chromophore, backbone and side-chains in EL222. Protein Sci 2023; 32:e4590. [PMID: 36764820 PMCID: PMC10019195 DOI: 10.1002/pro.4590] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2022] [Revised: 02/01/2023] [Accepted: 02/06/2023] [Indexed: 02/12/2023]
Abstract
Photoreceptors containing the light-oxygen-voltage (LOV) domain elicit biological responses upon excitation of their flavin mononucleotide (FMN) chromophore by blue light. The mechanism and kinetics of dark-state recovery are not well understood. Here we incorporated the non-canonical amino acid p-cyanophenylalanine (CNF) by genetic code expansion technology at forty-five positions of the bacterial transcription factor EL222. Screening of light-induced changes in infrared (IR) absorption frequency, electric field and hydration of the nitrile groups identified residues CNF31 and CNF35 as reporters of monomer/oligomer and caged/decaged equilibria, respectively. Time-resolved multi-probe UV/Visible and IR spectroscopy experiments of the lit-to-dark transition revealed four dynamical events. Predominantly, rearrangements around the A'α helix interface (CNF31 and CNF35) precede FMN-cysteinyl adduct scission, folding of α-helices (amide bands), and relaxation of residue CNF151. This study illustrates the importance of characterizing all parts of a protein and suggests a key role for the N-terminal A'α extension of the LOV domain in controlling EL222 photocycle length. This article is protected by copyright. All rights reserved.
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Affiliation(s)
- Aditya S Chaudhari
- Institute of Biotechnology of the Czech Academy of Sciences, Vestec, Czech Republic.,Faculty of Science, Charles University, Prague, Czech Republic
| | - Aditi Chatterjee
- Institute of Biotechnology of the Czech Academy of Sciences, Vestec, Czech Republic.,Faculty of Science, Charles University, Prague, Czech Republic
| | - Catarina A O Domingos
- Institute of Biotechnology of the Czech Academy of Sciences, Vestec, Czech Republic.,Escola Superior de Tecnologia do Barreiro, Instituto Politécnico de Setúbal, Lavradio, Portugal
| | | | - Yingliang Liu
- Institute of Biotechnology of the Czech Academy of Sciences, Vestec, Czech Republic
| | - Inger Andersson
- Institute of Biotechnology of the Czech Academy of Sciences, Vestec, Czech Republic.,Department of Cell and Molecular Biology, Uppsala University, Uppsala, Sweden
| | - Bohdan Schneider
- Institute of Biotechnology of the Czech Academy of Sciences, Vestec, Czech Republic
| | | | - Gustavo Fuertes
- Institute of Biotechnology of the Czech Academy of Sciences, Vestec, Czech Republic
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16
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Jiang HK, Tharp JM. Reprogramming Initiator and Nonsense Codons to Simultaneously Install Three Distinct Noncanonical Amino Acids into Proteins in E. coli. Methods Mol Biol 2023; 2676:101-116. [PMID: 37277627 DOI: 10.1007/978-1-0716-3251-2_7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Multiple noncanonical amino acids can be installed into proteins in E. coli using mutually orthogonal aminoacyl-tRNA synthetase and tRNA pairs. Here we describe a protocol for simultaneously installing three distinct noncanonical amino acids into proteins for site-specific bioconjugation at three sites. This method relies on an engineered, UAU-suppressing, initiator tRNA, which is aminoacylated with a noncanonical amino acid by Methanocaldococcus jannaschii tyrosyl-tRNA synthetase. Using this initiator tRNA/aminoacyl-tRNA synthetase pair, together with the pyrrolysyl-tRNA synthetase/tRNAPyl pairs from Methanosarcina mazei and Ca. Methanomethylophilus alvus, three noncanonical amino acids can be installed into proteins in response to the UAU, UAG, and UAA codons.
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Affiliation(s)
- Han-Kai Jiang
- Department of Molecular Biophysics & Biochemistry, Yale University, New Haven, CT, USA
- Institute of Biological Chemistry, Academia Sinica, Taipei, Taiwan
- Chemical Biology & Molecular Biophysics Program, Taiwan International Graduate Program, Academia Sinica, Taipei, Taiwan
- Department of Chemistry, National Tsing Hua University, Hsinchu, Taiwan
| | - Jeffery M Tharp
- Department of Biochemistry & Molecular Biology, Indiana University School of Medicine, Indianapolis, IN, USA.
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17
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Brown W, Rosenblum C, Deiters A. Small-Molecule Phosphine Activation of Protein Function in Zebrafish Embryos with an Expanded Genetic Code. Methods Mol Biol 2023; 2676:247-263. [PMID: 37277638 DOI: 10.1007/978-1-0716-3251-2_18] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Conditional control of protein function in a living model organism is an important tool for studying the effects of that protein during development and disease. In this chapter, we walk through the steps to generate a small-molecule-activatable enzyme in zebrafish embryos through the incorporation of a noncanonical amino acid into the protein active site. This method can be applied to many enzyme classes, which we highlight with temporal control of a luciferase and a protease. We demonstrate that strategic placement of the noncanonical amino acid completely blocks enzyme activity, which is then promptly restored after addition of the nontoxic small molecule inducer to the embryo water.
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Affiliation(s)
- Wes Brown
- Department of Chemistry, University of Pittsburgh, Pittsburgh, PA, USA
| | - Carolyn Rosenblum
- Department of Chemistry, University of Pittsburgh, Pittsburgh, PA, USA
| | - Alexander Deiters
- Department of Chemistry, University of Pittsburgh, Pittsburgh, PA, USA.
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18
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Chen J, Huang Y, Gan WB, Tsai YH. Selective Inhibition of Kinase Activity in Mammalian Cells by Bioorthogonal Ligand Tethering. Methods Mol Biol 2023; 2676:215-232. [PMID: 37277636 DOI: 10.1007/978-1-0716-3251-2_16] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Enzymes are critical for cellular functions, and malfunction of enzymes is closely related to many human diseases. Inhibition studies can help in deciphering the physiological roles of enzymes and guide conventional drug development programs. In particular, chemogenetic approaches enabling rapid and selective inhibition of enzymes in mammalian cells have unique advantages. Here, we describe the procedure for rapid and selective inhibition of a kinase in mammalian cells by bioorthogonal ligand tethering (iBOLT). Briefly, a non-canonical amino acid bearing a bioorthogonal group is genetically incorporated into the target kinase by genetic code expansion. The sensitized kinase can react with a conjugate containing a complementary biorthogonal group linked with a known inhibitory ligand. As a result, tethering of the conjugate to the target kinase allows selective inhibition of protein function. Here, we demonstrate this method by using cAMP-dependent protein kinase catalytic subunit alpha (PKA-Cα) as the model enzyme. The method should be applicable to other kinases, enabling their rapid and selective inhibition.
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Affiliation(s)
- Jinghao Chen
- Institute of Molecular Physiology, Shenzhen Bay Laboratory, Shenzhen, China
- School of Pharmaceutical Sciences (Shenzhen), Sun Yat-Sen University, Shenzhen, China
| | - Yang Huang
- Institute of Molecular Physiology, Shenzhen Bay Laboratory, Shenzhen, China
- School of Basic Medical Sciences, Capital Medical University, Beijing, China
| | - Wen-Biao Gan
- Institute of Neurological and Psychiatric Disorders, Shenzhen Bay Laboratory, Shenzhen, China
| | - Yu-Hsuan Tsai
- Institute of Molecular Physiology, Shenzhen Bay Laboratory, Shenzhen, China.
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19
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He X, Chen Y, Guo J, Niu W. Site-Specific Incorporation of Sulfotyrosine into Proteins in Mammalian Cells. Methods Mol Biol 2023; 2676:233-243. [PMID: 37277637 DOI: 10.1007/978-1-0716-3251-2_17] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Protein tyrosine O-sulfation (PTS) plays a crucial role in numerous extracellular protein-protein interactions. It is involved in diverse physiological processes and the development of human diseases, including AIDS and cancer. To facilitate the study of PTS in live mammalian cells, an approach for the site-specific synthesis of tyrosine-sulfated proteins (sulfoproteins) was developed. This approach takes advantage of an evolved Escherichia coli tyrosyl-tRNA synthetase to genetically encode sulfotyrosine (sTyr) into any proteins of interest (POI) in response to a UAG stop codon. Here, we give a step-by-step account of the incorporation of sTyr in HEK293T cells using the enhanced green fluorescent protein as an example. This method can be widely applied to incorporating sTyr into any POI to investigate the biological functions of PTS in mammalian cells.
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Affiliation(s)
- Xinyuan He
- Department of Chemical & Biomolecular Engineering, University of Nebraska-Lincoln, Lincoln, NE, USA
| | - Yan Chen
- Department of Chemistry, University of Nebraska-Lincoln, Lincoln, NE, USA
| | - Jiantao Guo
- Department of Chemistry, University of Nebraska-Lincoln, Lincoln, NE, USA.
- The Nebraska Center for Integrated Biomolecular Communication (NCIBC), University of Nebraska-Lincoln, Lincoln, NE, USA.
| | - Wei Niu
- Department of Chemical & Biomolecular Engineering, University of Nebraska-Lincoln, Lincoln, NE, USA.
- The Nebraska Center for Integrated Biomolecular Communication (NCIBC), University of Nebraska-Lincoln, Lincoln, NE, USA.
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20
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Chen Y, Gao T, He X, Niu W, Guo J. Genetic Code Expansion in Mammalian Cells Through Quadruplet Codon Decoding. Methods Mol Biol 2023; 2676:181-190. [PMID: 37277633 DOI: 10.1007/978-1-0716-3251-2_13] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Genetic code expansion enables the site-specific incorporation of noncanonical amino acids (ncAAs) into proteins both in vitro and in vivo. In addition to a widely applied nonsense suppression strategy, the use of quadruplet codons could further expand the genetic code. A general approach to genetically incorporate ncAAs in response to quadruplet codons is achieved by utilizing an engineered aminoacyl-tRNA synthetase (aaRS) together with a tRNA variant containing an expanded anticodon loop. Here we provide a protocol to decode quadruplet UAGA codon with a ncAA in mammalian cells. We also describe microscopy imaging and flow cytometry analysis of ncAA mutagenesis in response to quadruplet codons.
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Affiliation(s)
- Yan Chen
- Department of Chemistry, University of Nebraska-Lincoln, Lincoln, NE, USA
| | - Tianyu Gao
- Department of Chemistry, University of Nebraska-Lincoln, Lincoln, NE, USA
| | - Xinyuan He
- Department of Chemical & Biomolecular Engineering, University of Nebraska-Lincoln, Lincoln, NE, USA
| | - Wei Niu
- Department of Chemical & Biomolecular Engineering, University of Nebraska-Lincoln, Lincoln, NE, USA.
| | - Jiantao Guo
- Department of Chemistry, University of Nebraska-Lincoln, Lincoln, NE, USA.
- The Nebraska Center for Integrated Biomolecular Communication (NCIBC), University of Nebraska-Lincoln, Lincoln, NE, USA.
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21
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Diecker J, Dörner W, Rüschenbaum J, Mootz HD. Unraveling Structural Information of Multi-Domain Nonribosomal Peptide Synthetases by Using Photo-Cross-Linking Analysis with Genetic Code Expansion. Methods Mol Biol 2023; 2670:165-185. [PMID: 37184704 DOI: 10.1007/978-1-0716-3214-7_8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/16/2023]
Abstract
Nonribosomal peptide synthetases (NRPSs) are large, multifunctional enzymes that facilitate the stepwise synthesis of modified peptides, many of which serve as important pharmaceutical products. Typically, NRPSs contain one module for the incorporation of one amino acid into the growing peptide chain. A module consists of the domains required for activation, covalent binding, condensation, termination, and optionally modification of the aminoacyl or peptidyl moiety. We here describe a protocol using genetically encoded photo-cross-linking amino acids to probe the 3D architecture of NRPSs by determining spatial proximity constraints. p-benzoyl-L-phenylalanine (BpF) is incorporated at positions of presumed contact interfaces between domains. The covalent cross-link products are visualized by SDS-PAGE-based methods and precisely mapped by tandem mass spectrometry. Originally intended to study the communication (COM) domains, a special pair of docking domains of unknown structure between two interacting subunits of one NRPS system, this cross-linking approach was also found to be useful to interrogate the spatial proximity of domains that are not connected on the level of the primary structure. The presented photo-cross-linking technique thus provides structural insights complementary to those obtained by protein crystallography and reports on the protein in solution.
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Affiliation(s)
- Julia Diecker
- University of Münster, Institute of Biochemistry, Münster, Germany
| | - Wolfgang Dörner
- University of Münster, Institute of Biochemistry, Münster, Germany
| | | | - Henning D Mootz
- University of Münster, Institute of Biochemistry, Münster, Germany.
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22
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Reinkemeier CD, Lemke EA. Synthetic Organelles for Multiple mRNA Selective Genetic Code Expansions in Eukaryotes. Methods Mol Biol 2023; 2563:341-369. [PMID: 36227482 DOI: 10.1007/978-1-0716-2663-4_17] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
Engineering new functionalities into living eukaryotic systems is one of the main goals of synthetic biology. To this end, often enzyme evolution or de novo protein design is employed, which each have their own advantages and disadvantages. As complimentary tools, we recently developed orthogonally translating and film-like synthetic organelles that allow to create new enzyme functionalities based on spatial separation. We applied this technology to genetic code expansion (GCE) and showed that it is possible to equip eukaryotic cells with multiple orthogonal genetic codes that enable the specific reprogramming of distinct translational machineries, each with single-residue precision.In this protocol, we describe how synthetic organelles can be used to perform mRNA selective GCE and how they can be further developed to allow the simultaneous incorporation of distinct noncanonical amino acids (ncAAs) into selected proteins and how this can be used to label proteins selectively with fluorescent dyes via bioorthogonal chemistry.
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Affiliation(s)
- Christopher D Reinkemeier
- Biocentre, Departments of Biology and Chemistry, Johannes Gutenberg University Mainz, Mainz, Germany
- Institute of Molecular Biology gGmbH, Mainz, Germany
| | - Edward A Lemke
- Biocentre, Departments of Biology and Chemistry, Johannes Gutenberg University Mainz, Mainz, Germany.
- Institute of Molecular Biology gGmbH, Mainz, Germany.
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23
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Xuan W, Yang X. Semisynthesis of Glutamine-Methylated Proteins Enabled by Genetic Code Expansion. Methods Mol Biol 2023; 2676:147-156. [PMID: 37277630 DOI: 10.1007/978-1-0716-3251-2_10] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Gln methylation is a newly identified histone mark and mediates ribosomal biogenesis. Site-specifically Gln-methylated proteins are valuable tools to elucidate the biological implications of this modification. Herein, we describe a protocol to generate histones with site-specific Gln methylation in a semisynthetic manner. Firstly, an esterified glutamic acid analogue (BnE) is genetically encoded into proteins by genetic code expansion with high efficiency, which can be quantitatively converted into an acyl hydrazide via hydrazinolysis. Then, through a reaction with acetyl acetone, the acyl hydrazide is converted to reactive Knorr pyrazole. Finally, the in situ generated Knorr pyrazole is incubated with methylamine to give Gln methylation.
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Affiliation(s)
- Weimin Xuan
- School of Life Sciences, Tianjin University, Tianjin, China.
| | - Xiaochen Yang
- State Key Laboratory and Institute of Elemento-Organic Chemistry, College of Chemistry, Nankai University, Tianjin, China
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24
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Sun H, Huang Y, Tsai YH. Genetically Encoded 1,2-Aminothiol for Site-Specific Modification of a Cellular Membrane Protein via TAMM Condensation. Methods Mol Biol 2023; 2676:191-199. [PMID: 37277634 DOI: 10.1007/978-1-0716-3251-2_14] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Site-specific modification of proteins has wide applications in probing and perturbing biological systems. A popular means to achieve such a modification on a target protein is through a reaction between bioorthogonal functionalities. Indeed, various bioorthogonal reactions have been developed, including a recently reported reaction between 1,2-aminothiol and ((alkylthio)(aryl)methylene)malononitrile (TAMM). Here, we describe the procedure that combines genetic code expansion and TAMM condensation for site-specific modification of cellular membrane proteins. The 1,2-aminothiol functionality is introduced through a genetically incorporated noncanonical amino acid to a model membrane protein on mammalian cells. Treatment of the cells with a fluorophore-TAMM conjugate leads to fluorescent labeling of the target protein. This method can be applied to modify different membrane proteins on live mammalian cells.
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Affiliation(s)
- Han Sun
- Institute of Molecular Physiology, Shenzhen Bay Laboratory, Shenzhen, China
| | - Yang Huang
- Institute of Molecular Physiology, Shenzhen Bay Laboratory, Shenzhen, China
- School of Basic Medical Sciences, Capital Medical University, Beijing, China
| | - Yu-Hsuan Tsai
- Institute of Molecular Physiology, Shenzhen Bay Laboratory, Shenzhen, China.
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25
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Chung CZ, Söll D, Krahn N. Creating Selenocysteine-Specific Reporters Using Inteins. Methods Mol Biol 2023; 2676:69-86. [PMID: 37277625 DOI: 10.1007/978-1-0716-3251-2_5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
The selenium moiety in selenocysteine (Sec) imparts enhanced chemical properties to this amino acid and ultimately the protein in which it is inserted. These characteristics are attractive for designing highly active enzymes or extremely stable proteins and studying protein folding or electron transfer, to name a few. There are also 25 human selenoproteins, of which many are essential for our survival. The ability to create or study these selenoproteins is significantly hindered by the inability to easily produce them. Engineering translation has yielded simpler systems to facilitate site-specific insertion of Sec; however, Ser misincorporation remains problematic. Therefore, we have designed two Sec-specific reporters which promote high-throughput screening of Sec translation systems to overcome this barrier. This protocol outlines the workflow to engineer these Sec-specific reporters, with the application to any gene of interest and the ability to transfer this strategy to any organism.
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Affiliation(s)
- Christina Z Chung
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT, USA
| | - Dieter Söll
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT, USA
- Department of Chemistry, Yale University, New Haven, CT, USA
| | - Natalie Krahn
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT, USA.
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26
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Li M, Peng T. Genetic Encoding of a Fluorescent Noncanonical Amino Acid as a FRET Donor for the Analysis of Deubiquitinase Activities. Methods Mol Biol 2023; 2676:55-67. [PMID: 37277624 DOI: 10.1007/978-1-0716-3251-2_4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
The genetic code expansion technology enables the genetic encoding of fluorescent noncanonical amino acids (ncAAs) for site-specific fluorescent labeling of proteins. These co-translational and internal fluorescent tags have been harnessed to establish genetically encoded Förster resonance energy transfer (FRET) probes for studying protein structural changes and interactions. Here, we describe the protocols for site-specific incorporation of an aminocoumarin-derived fluorescent ncAA into proteins in E. coli and preparation of a fluorescent ncAA-based FRET probe for assaying the activities of deubiquitinases, a key class of enzymes involved in ubiquitination. We also describe the deployment of an in vitro fluorescence assay to screen and analyze small-molecule inhibitors against deubiquitinases.
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Affiliation(s)
- Manjia Li
- State Key Laboratory of Chemical Oncogenomics, School of Chemical Biology and Biotechnology, Peking University Shenzhen Graduate School, Shenzhen, China
| | - Tao Peng
- State Key Laboratory of Chemical Oncogenomics, School of Chemical Biology and Biotechnology, Peking University Shenzhen Graduate School, Shenzhen, China.
- Institute of Chemical Biology, Shenzhen Bay Laboratory, Shenzhen, China.
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27
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Bridge T, Sachdeva A. Engineering Homogeneous Photoactive Antibody Fragments. Methods Mol Biol 2023; 2676:21-40. [PMID: 37277622 DOI: 10.1007/978-1-0716-3251-2_2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Genetically encoded site-specifically incorporated noncanonical amino acids (ncAAs) have been used to modulate properties of several proteins. Here, we describe a procedure for engineering photoactive antibody fragments that bind to their target antigen only after irradiation with 365 nm light. The procedure starts with identification of tyrosine residues in antibody fragments that are important for antibody-antigen binding and thus targets for replacement with photocaged tyrosine (pcY). This is followed by cloning of plasmids and expression of pcY-containing antibody fragments in E. coli. Finally, we describe a cost-effective and biologically-relevant method for measuring the binding affinity of photoactive antibody fragments to antigens expressed on the surface of live cancer cells.
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Affiliation(s)
- Thomas Bridge
- School of Chemistry, University of East Anglia, Norwich, UK
| | - Amit Sachdeva
- School of Chemistry, University of East Anglia, Norwich, UK.
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28
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Wang Y, Cai W, Han B, Liu T. Protein Expression with Biosynthesized Noncanonical Amino Acids. Methods Mol Biol 2023; 2676:87-100. [PMID: 37277626 DOI: 10.1007/978-1-0716-3251-2_6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Natural proteins are normally made by 20 canonical amino acids. Genetic code expansion (GCE) enables incorporation of diverse chemically synthesized noncanonical amino acids (ncAAs) by orthogonal aminoacyl-tRNA synthetase (aaRS)/tRNA pairs using nonsense codons, which could significantly expand new functionalities of proteins in both scientific and biomedical applications. Here, by hijacking the cysteine biosynthetic enzymes, we describe a method combining amino acid biosynthesis and GCE to introduce around 50 structurally novel ncAAs into proteins by supplementation of commercially available aromatic thiol precursors, thus eliminating the need to chemically synthesize these ncAAs. A screening method is also provided for improving the incorporation efficiency of a particular ncAA. Furthermore, we demonstrate bioorthogonal groups, such as azide and ketone, that are compatible with our system and can be easily introduced into protein for subsequent site-specific labeling.
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Affiliation(s)
- Yong Wang
- State Key Laboratory of Natural and Biomimetic Drugs, Chemical Biology Center, Department of Molecular and Cellular Pharmacology, Pharmaceutical Sciences, Peking University, Beijing, China
| | - Wenkang Cai
- State Key Laboratory of Natural and Biomimetic Drugs, Chemical Biology Center, Department of Molecular and Cellular Pharmacology, Pharmaceutical Sciences, Peking University, Beijing, China
| | - Boyang Han
- State Key Laboratory of Natural and Biomimetic Drugs, Chemical Biology Center, Department of Molecular and Cellular Pharmacology, Pharmaceutical Sciences, Peking University, Beijing, China
| | - Tao Liu
- State Key Laboratory of Natural and Biomimetic Drugs, Chemical Biology Center, Department of Molecular and Cellular Pharmacology, Pharmaceutical Sciences, Peking University, Beijing, China.
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29
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Wu Z, Wang J. Genetic Code Expansion in Mammalian Cells. Methods Mol Biol 2023; 2676:159-167. [PMID: 37277631 DOI: 10.1007/978-1-0716-3251-2_11] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
The expansion of the genetic code has enabled the incorporation of noncanonical amino acids (ncAAs) into a defined site of proteins. By introducing such a unique handle into the protein of interest (POI), bioorthogonal reactions can be utilized in live cells to monitor or manipulate the interaction, translocation, function, and modification of the POI. Here, we describe a basic protocol outlining the necessary steps to incorporate a ncAA into a POI in mammalian cells.
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Affiliation(s)
- Zhigang Wu
- Department of Chemistry, Southern University of Science and Technology, Shenzhen, China
| | - Jie Wang
- Department of Chemistry, Southern University of Science and Technology, Shenzhen, China.
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Guo AD, Chen XH. Genetically Encoded Noncanonical Amino Acids in Proteins to Investigate Lysine Benzoylation. Methods Mol Biol 2023; 2676:131-146. [PMID: 37277629 DOI: 10.1007/978-1-0716-3251-2_9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Posttranslational modifications (PTMs) of lysine residues are major regulators of gene expression, protein-protein interactions, and protein localization and degradation. Histone lysine benzoylation is a recently identified epigenetic marker associated with active transcription, which has physiological relevance distinct from histone acetylation and can be regulated by debenzoylation of sirtuin 2 (SIRT2). Herein, we provide a protocol for the incorporation of benzoyllysine and fluorinated benzoyllysine into full-length histone proteins, which further serve as benzoylated histone probes with NMR or fluorescence signal for investigating the dynamics of SIRT2-mediated debenzoylation.
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Affiliation(s)
- An-Di Guo
- School of Pharmaceutical Science and Technology, Hangzhou Institute for Advanced Study, University of Chinese Academy of Sciences, Hangzhou, China
- State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, China
| | - Xiao-Hua Chen
- School of Pharmaceutical Science and Technology, Hangzhou Institute for Advanced Study, University of Chinese Academy of Sciences, Hangzhou, China.
- State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, China.
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Zheng Z, Xia Q. Noncanonical Amino Acid Incorporation in Mice. Methods Mol Biol 2023; 2676:265-284. [PMID: 37277639 DOI: 10.1007/978-1-0716-3251-2_19] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Genetic code expansion enables in cellulo biosynthesis of curative proteins with enhanced specificity, improved stability, and even novel functions, due to the incorporation of artificial, designed, noncanonical amino acids (ncAAs). In addition, this orthogonal system also holds great potential for in vivo suppressing nonsense mutations during protein translation, providing an alternative strategy for alleviating inherited diseases caused by premature termination codons (PTCs). Here we describe the approach to explore the therapeutic efficacy and long-term safety of this strategy in transgenic mdx mice with stably expanded genetic codes. Theoretically, this method is applicable to about 11% of monogenic diseases involving nonsense mutations.
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Affiliation(s)
- Zhetao Zheng
- State Key Laboratory of Natural and Biomimetic Drugs, Department of Chemical Biology, School of Pharmaceutical Sciences, Peking University, Beijing, China
| | - Qing Xia
- State Key Laboratory of Natural and Biomimetic Drugs, Department of Chemical Biology, School of Pharmaceutical Sciences, Peking University, Beijing, China.
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32
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Meineke B, Elsässer SJ. Generation of Amber Suppression Cell Lines Using CRISPR-Cas9. Methods Mol Biol 2023; 2676:169-180. [PMID: 37277632 DOI: 10.1007/978-1-0716-3251-2_12] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Genetic code expansion via amber suppression allows cotranslational, site-specific introduction of nonnatural chemical groups into proteins in the living cell. The archaeal pyrrolysine-tRNA/pyrrolysine-tRNA synthetase (PylT/RS) pair from Methanosarcina mazei (Mma) has been established for incorporation of a wide range of noncanonical amino acids (ncAAs) in mammalian cells. Once integrated in an engineered protein, ncAAs allow for simple click-chemistry derivatization, photo-cage control of enzyme activity, and site-specific placement of posttranslational modifications. We previously described a modular amber suppression plasmid system for generating stable cell lines via piggyBac transposition in a range of mammalian cells. Here we detail a general protocol for the generation of CRISPR-Cas9 knock-in cell lines using the same plasmid system. The knock-in strategy relies on CRISPR-Cas9-induced double-strand breaks (DSBs) and nonhomologous end joining (NHEJ) repair to target the PylT/RS expression cassette to the AAVS1 safe harbor locus in human cells. MmaPylRS expression from this single locus is sufficient for efficient amber suppression when the cells are subsequently transfected transiently with a PylT/gene of interest plasmid.
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Affiliation(s)
- Birthe Meineke
- Laboratory of Synthetic and Systems Biology, Science for Life Laboratory, Department of Medical Biochemistry and Biophysics, Division of Genome Biology, Karolinska Institutet, Solna, Stockholm, Sweden.
| | - Simon J Elsässer
- Laboratory of Synthetic and Systems Biology, Science for Life Laboratory, Department of Medical Biochemistry and Biophysics, Division of Genome Biology, Karolinska Institutet, Solna, Stockholm, Sweden
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Hiefinger C, Mandl S, Wieland M, Kneuttinger A. Rational design, production and in vitro analysis of photoxenoproteins. Methods Enzymol 2023; 682:247-288. [PMID: 36948704 DOI: 10.1016/bs.mie.2022.12.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
In synthetic biology, the artificial control of proteins by light is of growing interest since it enables the spatio-temporal regulation of downstream molecular processes. This precise photocontrol can be established by the site-directed incorporation of photo-sensitive non-canonical amino acids (ncAAs) into proteins, which generates so-called photoxenoproteins. Photoxenoproteins can be engineered using ncAAs that facilitate the irreversible activation or reversible regulation of their activity upon irradiation. In this chapter, we provide a general outline of the engineering process based on the current methodological state-of-the-art to obtain artificial photocontrol in proteins using the ncAAs o-nitrobenzyl-O-tyrosine as example for photocaged ncAAs (irreversible), and phenylalanine-4'-azobenzene as example for photoswitchable ncAAs (reversible). We thereby focus on the initial design as well as the production and characterization of photoxenoproteins in vitro. Finally, we outline the analysis of photocontrol under steady-state and non-steady-state conditions using the allosteric enzyme complexes imidazole glycerol phosphate synthase and tryptophan synthase as examples.
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Affiliation(s)
- Caroline Hiefinger
- Institute of Biophysics and Physical Biochemistry & Regensburg Center for Biochemistry, University of Regensburg, Regensburg, Germany
| | - Sabrina Mandl
- Institute of Biophysics and Physical Biochemistry & Regensburg Center for Biochemistry, University of Regensburg, Regensburg, Germany
| | - Mona Wieland
- Institute of Biophysics and Physical Biochemistry & Regensburg Center for Biochemistry, University of Regensburg, Regensburg, Germany
| | - Andrea Kneuttinger
- Institute of Biophysics and Physical Biochemistry & Regensburg Center for Biochemistry, University of Regensburg, Regensburg, Germany.
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Zhang H, Zheng Z, Dong L, Shi N, Yang Y, Chen H, Shen Y, Xia Q. Rational incorporation of any unnatural amino acid into proteins by machine learning on existing experimental proofs. Comput Struct Biotechnol J 2022; 20:4930-4941. [PMID: 36147660 PMCID: PMC9472073 DOI: 10.1016/j.csbj.2022.08.063] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2022] [Revised: 08/28/2022] [Accepted: 08/28/2022] [Indexed: 11/26/2022] Open
Abstract
The unnatural amino acid (UAA) incorporation technique through genetic code expansion has been extensively used in protein engineering for the last two decades. Mutations into UAAs offer more dimensions to tune protein structures and functions. However, the huge library of optional UAAs and various circumstances of mutation sites on different proteins urge rational UAA incorporations guided by artificial intelligence. Here we collected existing experimental proofs of UAA-incorporated proteins in literature and established a database of known UAA substitution sites. By program designing and machine learning on the database, we showed that UAA incorporations into proteins are predictable by the observed evolutional, steric and physiochemical factors. Based on the predicted probability of successful UAA substitutions, we tested the model performance using literature-reported and freshly-designed experimental proofs, and demonstrated its potential in screening UAA-incorporated proteins. This work expands structure-based computational biology and virtual screening to UAA-incorporated proteins, and offers a useful tool to automate the rational design of proteins with any UAA.
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Affiliation(s)
- Haoran Zhang
- State Key Laboratory of Natural and Biomimetic Drugs, Department of Chemical Biology, School of Pharmaceutical Sciences, Peking University, Beijing 100191, China
| | - Zhetao Zheng
- State Key Laboratory of Natural and Biomimetic Drugs, Department of Chemical Biology, School of Pharmaceutical Sciences, Peking University, Beijing 100191, China
| | - Liangzhen Dong
- State Key Laboratory of Natural and Biomimetic Drugs, Department of Chemical Biology, School of Pharmaceutical Sciences, Peking University, Beijing 100191, China
| | - Ningning Shi
- State Key Laboratory of Natural and Biomimetic Drugs, Department of Chemical Biology, School of Pharmaceutical Sciences, Peking University, Beijing 100191, China
| | - Yuelin Yang
- State Key Laboratory of Natural and Biomimetic Drugs, Department of Chemical Biology, School of Pharmaceutical Sciences, Peking University, Beijing 100191, China
| | - Hongmin Chen
- State Key Laboratory of Natural and Biomimetic Drugs, Department of Chemical Biology, School of Pharmaceutical Sciences, Peking University, Beijing 100191, China
| | - Yuxuan Shen
- State Key Laboratory of Natural and Biomimetic Drugs, Department of Chemical Biology, School of Pharmaceutical Sciences, Peking University, Beijing 100191, China
| | - Qing Xia
- State Key Laboratory of Natural and Biomimetic Drugs, Department of Chemical Biology, School of Pharmaceutical Sciences, Peking University, Beijing 100191, China
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Pastore AJ, Ficaretta E, Chatterjee A, Davidson VL. Substitution of the sole tryptophan of the cupredoxin, amicyanin, with 5-hydroxytryptophan alters fluorescence properties and energy transfer to the type 1 copper site. J Inorg Biochem 2022; 234:111895. [PMID: 35696758 PMCID: PMC9753554 DOI: 10.1016/j.jinorgbio.2022.111895] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2022] [Revised: 05/17/2022] [Accepted: 06/02/2022] [Indexed: 12/01/2022]
Abstract
Amicyanin is a type 1 copper protein with a single tryptophan residue. Using genetic code expansion, the tryptophan was selectively replaced with the unnatural amino acid, 5-hydroxytryptophan (5-HTP). The 5-HTP substituted amicyanin exhibited absorbance at 300-320 nm, characteristic of 5-HTP and not seen in native amicyanin. The fluorescence emission maximum in 5-HTP substituted amicyanin is redshifted from 318 nm in native amicyanin to 331 nm and to 348 nm in the unfolded protein. The fluorescence quantum yield of 5-HTP substituted amicyanin mutant was much less than that of native amicyanin. Differences in intrinsic fluorescence are explained by differences in the excited states of tryptophan versus 5-HTP and the intraprotein environment. The substitution of tryptophan with 5-HTP did not affect the visible absorbance and redox potential of the copper, which is 10 Å away. In amicyanin and other cupredoxins, an unexplained quenching of the intrinsic fluorescence by the bound copper is observed. However, the fluorescence of 5-HTP substituted amicyanin is not quenched by the copper. It is shown that the mechanism of quenching in native amicyanin is Förster, or fluorescence, resonance energy transfer (FRET). This does not occur in 5-HTP substituted amicyanin because the fluorescence quantum yield is significantly lower and the red-shift of fluorescence emission maximum decreases overlap with the near UV absorbance of copper. Characterization of the distinct fluorescence properties of 5-HTP relative to tryptophan in amicyanin provides a basis for spectroscopic interrogation of the protein microenvironment using 5-HTP, and long-distance interactions with transition metals.
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Affiliation(s)
- Anthony J Pastore
- Burnett School of Biomedical Sciences, College of Medicine, University of Central Florida, Orlando, FL, 32827, USA
| | - Elise Ficaretta
- Department of Chemistry, Boston College, 2609 Beacon Street, Chestnut Hill, MA 02467, USA
| | - Abhishek Chatterjee
- Department of Chemistry, Boston College, 2609 Beacon Street, Chestnut Hill, MA 02467, USA
| | - Victor L Davidson
- Burnett School of Biomedical Sciences, College of Medicine, University of Central Florida, Orlando, FL, 32827, USA.
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Hauptstein N, Pouyan P, Wittwer K, Cinar G, Scherf-Clavel O, Raschig M, Licha K, Lühmann T, Nischang I, Schubert US, Pfaller CK, Haag R, Meinel L. Polymer selection impacts the pharmaceutical profile of site-specifically conjugated Interferon-α2a. J Control Release 2022; 348:881-892. [PMID: 35764249 DOI: 10.1016/j.jconrel.2022.05.060] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2022] [Revised: 04/12/2022] [Accepted: 05/15/2022] [Indexed: 12/15/2022]
Abstract
Conjugation of poly(ethylene glycol) (PEG) to biologics is a successful strategy to favorably impact the pharmacokinetics and efficacy of the resulting bioconjugate. We compare bioconjugates synthesized by strain-promoted azide-alkyne cycloaddition (SPAAC) using PEG and linear polyglycerol (LPG) of about 20 kDa or 40 kDa, respectively, with an azido functionalized human Interferon-α2a (IFN-α2a) mutant. Site-specific PEGylation and LPGylation resulted in IFN-α2a bioconjugates with improved in vitro potency compared to commercial Pegasys. LPGylated bioconjugates had faster disposition kinetics despite comparable hydrodynamic radii to their PEGylated analogues. Overall exposure of the PEGylated IFN-α2a with a 40 kDa polymer exceeded Pegasys, which, in return, was similar to the 40 kDa LPGylated conjugates. The study points to an expanded polymer design space through which the selected polymer class may result in a different distribution of the studied bioconjugates.
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Affiliation(s)
- Niklas Hauptstein
- Institute of Pharmacy and Food Chemistry, University of Würzburg, Am Hubland, 97074 Würzburg, Germany
| | - Paria Pouyan
- Institute of Chemistry and Biochemistry, Freie Universität Berlin, Takustr. 3, 14195 Berlin, Germany
| | - Kevin Wittwer
- Paul-Ehrlich-Institute, Division of Veterinary Medicine, Paul-Ehrlich-Str. 51-59, 63225 Langen, Germany
| | - Gizem Cinar
- Laboratory of Organic and Macromolecular Chemistry (IOMC), Friedrich Schiller University Jena, Humboldtstr. 10, 07743 Jena, Germany; Jena Center for Soft Matter (JCSM), Friedrich Schiller University Jena, Philosophenweg 7, 07743 Jena, Germany
| | - Oliver Scherf-Clavel
- Institute of Pharmacy and Food Chemistry, University of Würzburg, Am Hubland, 97074 Würzburg, Germany
| | - Martina Raschig
- Institute of Pharmacy and Food Chemistry, University of Würzburg, Am Hubland, 97074 Würzburg, Germany
| | - Kai Licha
- Institute of Chemistry and Biochemistry, Freie Universität Berlin, Takustr. 3, 14195 Berlin, Germany
| | - Tessa Lühmann
- Institute of Pharmacy and Food Chemistry, University of Würzburg, Am Hubland, 97074 Würzburg, Germany
| | - Ivo Nischang
- Laboratory of Organic and Macromolecular Chemistry (IOMC), Friedrich Schiller University Jena, Humboldtstr. 10, 07743 Jena, Germany; Jena Center for Soft Matter (JCSM), Friedrich Schiller University Jena, Philosophenweg 7, 07743 Jena, Germany
| | - Ulrich S Schubert
- Laboratory of Organic and Macromolecular Chemistry (IOMC), Friedrich Schiller University Jena, Humboldtstr. 10, 07743 Jena, Germany; Jena Center for Soft Matter (JCSM), Friedrich Schiller University Jena, Philosophenweg 7, 07743 Jena, Germany
| | - Christian K Pfaller
- Paul-Ehrlich-Institute, Division of Veterinary Medicine, Paul-Ehrlich-Str. 51-59, 63225 Langen, Germany
| | - Rainer Haag
- Institute of Chemistry and Biochemistry, Freie Universität Berlin, Takustr. 3, 14195 Berlin, Germany
| | - Lorenz Meinel
- Institute of Pharmacy and Food Chemistry, University of Würzburg, Am Hubland, 97074 Würzburg, Germany; Helmholtz Institute for RNA-Based Infection Research (HIRI), 97080 Würzburg, Germany.
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Rong L, Lim RM, Yin X, Tan L, Yang JH, Xie J. Site-Specific Dinitrophenylation of Single-Chain Antibody Fragments for Redirecting a Universal CAR-T Cell against Cancer Antigens. J Mol Biol 2022; 434:167513. [PMID: 35218770 DOI: 10.1016/j.jmb.2022.167513] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2021] [Revised: 02/16/2022] [Accepted: 02/20/2022] [Indexed: 10/19/2022]
Abstract
We have previously developed a universal chimeric antigen receptor (CAR), which recognizes dinitrophenyl (DNP) and can redirect T and NK cells to target cancer and HIV antigens using DNP-conjugated antibodies as adaptor molecules. However, the DNP-antibody conjugates are generated by random modification, which may not be optimal for this modular system. Here, we report the development of enhanced adaptor molecules by site-specific DNP modification. We use the genetic code expansion technology to generate single-chain fragment variable (scFv) antibodies with site-specific DNP. We compare four anti-CD19 scFv mutants and find that the one with DNP at the flexible peptide linker between VH and VL is the most effective in redirecting anti-DNP CAR-T cells against CD19+ cells. The other three mutants are ineffective in doing so due to reduced DNP exposure or abrogated CD19 binding. We also use the anti-CD22 scFv as another model adaptor molecule and again find that the peptide linker is ideal for DNP derivatization. Our approach can potentially be used to design enhanced adaptor molecules to redirect the DNP-mediated universal CAR against other tumor antigens.
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Affiliation(s)
- Liang Rong
- Department of Pharmacology and Pharmaceutical Sciences, School of Pharmacy, University of Southern California, Los Angeles, CA 90089, USA
| | - Rebecca M Lim
- Department of Pharmacology and Pharmaceutical Sciences, School of Pharmacy, University of Southern California, Los Angeles, CA 90089, USA
| | - Xiaosuo Yin
- Department of Pharmacology and Pharmaceutical Sciences, School of Pharmacy, University of Southern California, Los Angeles, CA 90089, USA
| | - Liyao Tan
- Department of Pharmacology and Pharmaceutical Sciences, School of Pharmacy, University of Southern California, Los Angeles, CA 90089, USA
| | - Jae H Yang
- Department of Pharmacology and Pharmaceutical Sciences, School of Pharmacy, University of Southern California, Los Angeles, CA 90089, USA
| | - Jianming Xie
- Department of Pharmacology and Pharmaceutical Sciences, School of Pharmacy, University of Southern California, Los Angeles, CA 90089, USA; Norris Comprehensive Cancer Center, University of Southern California, Los Angeles, CA 90089, USA.
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Chung CZ, Söll D, Krahn N. Using selenocysteine-specific reporters to screen for efficient tRNA Sec variants. Methods Enzymol 2022; 662:63-93. [PMID: 35101219 DOI: 10.1016/bs.mie.2021.10.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
The unique properties of selenocysteine (Sec) have generated an interest in the scientific community to site-specifically incorporate Sec into a protein of choice. Current technologies have rewired the natural Sec-specific translation factor-dependent selenoprotein biosynthesis pathway by harnessing the canonical elongation factor (EF-Tu) to simplify the requirements for Sec incorporation in Escherichia coli. This strategy is versatile and can be applied to Sec incorporation at any position in a protein of interest. However, selenoprotein production is still limited by yield and serine misincorporation. This protocol outlines a method in E. coli to design and optimize tRNA libraries which can be selected and screened for by the use of Sec-specific intein-based reporters. This provides a fast and simple way to engineer tRNAs with enhanced Sec-incorporation ability.
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Affiliation(s)
- Christina Z Chung
- Department of Molecular Biophysics & Biochemistry, Yale University, New Haven, CT, United States
| | - Dieter Söll
- Department of Molecular Biophysics & Biochemistry, Yale University, New Haven, CT, United States; Department of Chemistry, Yale University, New Haven, CT, United States.
| | - Natalie Krahn
- Department of Molecular Biophysics & Biochemistry, Yale University, New Haven, CT, United States
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Aphicho K, Kittipanukul N, Uttamapinant C. Visualizing the complexity of proteins in living cells with genetic code expansion. Curr Opin Chem Biol 2022; 66:102108. [PMID: 35026612 DOI: 10.1016/j.cbpa.2021.102108] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2021] [Revised: 11/30/2021] [Accepted: 12/07/2021] [Indexed: 12/28/2022]
Abstract
Genetic code expansion has emerged as an enabling tool to provide insight into functions of understudied proteinogenic species, such as small proteins and peptides, and to probe protein biophysics in the cellular context. Here, we discuss recent technical advances and applications of genetic code expansion in cellular imaging of complex mammalian protein species, along with considerations and challenges on using the method.
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Affiliation(s)
- Kanokpol Aphicho
- School of Biomolecular Science and Engineering, Vidyasirimedhi Institute of Science and Technology (VISTEC), Rayong, Thailand
| | - Narongyot Kittipanukul
- School of Biomolecular Science and Engineering, Vidyasirimedhi Institute of Science and Technology (VISTEC), Rayong, Thailand
| | - Chayasith Uttamapinant
- School of Biomolecular Science and Engineering, Vidyasirimedhi Institute of Science and Technology (VISTEC), Rayong, Thailand.
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Yilmaz Z, Jedlitzke B, Mootz HD. Design and Preparation of Photobodies: Light-Activated Single-Domain Antibody Fragments. Methods Mol Biol 2022; 2446:409-424. [PMID: 35157286 DOI: 10.1007/978-1-0716-2075-5_21] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Nanobodies are single-domain antibody fragments that have found widespread use in basic research, therapy, and diagnostics. Like other antibody formats, nanobodies can be developed with high affinity and specificity for desired antigens. A photobody is a light-activatable nanobody, obtained by incorporating a photo-labile caging group into the paratope region. The caging group prevents antigen binding until removed with light (365 nm), thereby rendering the binding controllable with high temporal and spatial resolution. Thus far photocaged tyrosine residues have been used for this purpose, as tyrosine is a frequent residue at critical positions of nanobody paratopes. Nanobodies without a tyrosine residue at the antigen-binding interface may require a different strategy. In this chapter, we describe methods to design and prepare photobodies by recombinant expression in Escherichia coli in combination with genetic code expansion technology to incorporate ortho-nitrobenzyl-tyrosine residues. We use the conversion of the anti-green fluorescent protein enhancer nanobody into a photobody as an example. These protocols should be applicable to many other nanobodies.
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Affiliation(s)
- Zahide Yilmaz
- Department of Chemistry and Pharmacy, Institute of Biochemistry, University of Muenster, Münster, Germany
| | - Benedikt Jedlitzke
- Department of Chemistry and Pharmacy, Institute of Biochemistry, University of Muenster, Münster, Germany
| | - Henning D Mootz
- Department of Chemistry and Pharmacy, Institute of Biochemistry, University of Muenster, Münster, Germany.
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Abstract
Selenoproteins, which contain the 21st amino acid selenocysteine, play roles in maintaining cellular redox homeostasis. Many open questions remain in the field of selenoprotein biology, including the functions of a number of uncharacterized human selenoproteins, and the properties of selenocysteine compared to its analogous amino acid cysteine. The mechanism of selenocysteine incorporation involves an intricate machinery that deviates from the mechanism of incorporation for the canonical 20 amino acids. As a result, recombinant expression of selenoproteins has been historically challenging, and has hindered a deeper evaluation of selenoprotein biology. Genetic code expansion methods, which incorporate protected analogs of selenocysteine, allow the endogenous selenocysteine incorporation mechanism to be bypassed entirely to facilitate selenoprotein expression. Here we present a method for incorporating a photocaged selenocysteine amino acid (DMNB-Sec) into human selenoproteins directly in mammalian cells. This approach offers the opportunity to study human selenoproteins in their native cellular environment and should advance our understanding of selenoprotein biology.
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Nguyen TA, Gronauer T, Nast-Kolb T, Sieber S, Lang K. Substrate profiling of mitochondrial caseinolytic protease P via a site-specific photocrosslinking approach. Angew Chem Int Ed Engl 2021; 61:e202111085. [PMID: 34847623 PMCID: PMC9306725 DOI: 10.1002/anie.202111085] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2021] [Indexed: 11/17/2022]
Abstract
Approaches for profiling protease substrates are critical for defining protease functions, but remain challenging tasks. We combine genetic code expansion, photocrosslinking and proteomics to identify substrates of the mitochondrial (mt) human caseinolytic protease P (hClpP). Site‐specific incorporation of the diazirine‐bearing amino acid DiazK into the inner proteolytic chamber of hClpP, followed by UV‐irradiation of cells, allows to covalently trap substrate proteins of hClpP and to substantiate hClpP's major involvement in maintaining overall mt homeostasis. In addition to confirming many of the previously annotated hClpP substrates, our approach adds a diverse set of new proteins to the hClpP interactome. Importantly, our workflow allows identifying substrate dynamics upon application of external cues in an unbiased manner. Identification of unique hClpP‐substrate proteins upon induction of mt oxidative stress, suggests that hClpP counteracts oxidative stress by processing of proteins that are involved in respiratory chain complex synthesis and maturation as well as in catabolic pathways.
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Affiliation(s)
- Tuan-Anh Nguyen
- Technical University of Munich: Technische Universitat Munchen, Chemistry, Lichtenbergstr. 4, 85748, Garching, GERMANY
| | - Thomas Gronauer
- Technical University of Munich: Technische Universitat Munchen, Chemistry, Lichtenbergstr. 4, 85748, Garching, GERMANY
| | - Timon Nast-Kolb
- Technische Universität München: Technische Universitat Munchen, Physics, GERMANY
| | - Stephan Sieber
- Technical University of Munich: Technische Universitat Munchen, Chemistry, Lichtenbergstr. 4, 85748, Garching, GERMANY
| | - Kathrin Lang
- ETH-Zürich LOC: Eidgenossische Technische Hochschule Zurich Laboratorium fur Organische Chemie, Chemistry and Applied Biosciences, Vladimir-Prelog-Weg. 3, 8093, Zürich, SWITZERLAND
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Aarthy M, George A, Ayyadurai N. Beyond protein tagging: Rewiring the genetic code of fluorescent proteins - A review. Int J Biol Macromol 2021; 191:840-851. [PMID: 34560154 DOI: 10.1016/j.ijbiomac.2021.09.108] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2021] [Revised: 09/17/2021] [Accepted: 09/17/2021] [Indexed: 11/18/2022]
Abstract
Fluorescent proteins (FP) are an integral part of modern biology due to its diverse biochemical and photophysical properties. The boundaries of FP have been extended through conventional mutagenesis and directed evolution approaches. Engineering of FP based on the standard genetic code consisting of 20 amino acids with limited functional groups restrict its diversification. Degeneracy of genetic code has helped in covering this substantial gap through genetic code engineering, wherein introduction of unnatural amino acid (UAA) analogues resulted in a collection of FP with varying properties. This review features the work carried till date in the area of FP incorporated with UAAs and explores strategies employed for incorporation, impact of UAAs in chromophore and surrounding residues and changes in inherent properties of FP. The long-standing association of FP as a tool for high throughput screening of orthogonal aaRS/tRNA pairs used in site specific incorporation of UAAs is expounded. Insertion of UAAs in FP has enabled their use in contemporary fields such as biophotovoltaics, bioremediation, biosensors, biomaterials and imaging of acidic vesicles. Thus, expansion of genetic code of FP is envisaged to rejig the existing spectra of colors and future research initiative in this direction is expected to glow brighter and brighter.
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Affiliation(s)
- Mayilvahanan Aarthy
- Council of Scientific and Industrial Research (CSIR)-Central Leather Research Institute (CLRI), Chennai 600020, India
| | - Augustine George
- Council of Scientific and Industrial Research (CSIR)-Central Leather Research Institute (CLRI), Chennai 600020, India
| | - Niraikulam Ayyadurai
- Council of Scientific and Industrial Research (CSIR)-Central Leather Research Institute (CLRI), Chennai 600020, India.
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Reinkemeier CD, Lemke EA. Synthetic biomolecular condensates to engineer eukaryotic cells. Curr Opin Chem Biol 2021; 64:174-81. [PMID: 34600419 DOI: 10.1016/j.cbpa.2021.08.005] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2021] [Revised: 08/16/2021] [Accepted: 08/16/2021] [Indexed: 01/04/2023]
Abstract
The compartmentalization of specific functions into specialized organelles is a key feature of eukaryotic life. In particular, dynamic biomolecular condensates that are not membrane enclosed offer exciting opportunities for synthetic biology. In recent years, multiple approaches to generate and control condensates have been reported. Notably, multiple orthogonally translating organelles were designed that enable precise protein engineering inside living cells. Despite being built from only very few components, orthogonal translation can be engineered with subresolution precision at different places inside the same cell to create mammalian cells with multiple expanded genetic codes. This provides a pathway to engineer multiple proteins with multiple and distinct functionalities inside living eukaryotes and provides a general strategy toward spatially orthogonal enzyme engineering.
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Zhou W, Deiters A. Chemogenetic and optogenetic control of post-translational modifications through genetic code expansion. Curr Opin Chem Biol 2021; 63:123-131. [PMID: 33845403 PMCID: PMC8384655 DOI: 10.1016/j.cbpa.2021.02.016] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2020] [Revised: 02/23/2021] [Accepted: 02/25/2021] [Indexed: 02/08/2023]
Abstract
Post-translational modifications (PTMs) of proteins extensively diversify the biological information flow from the genome to the proteome and thus have profound pathophysiological implications. Precise dissection of the regulatory networks of PTMs benefits from the ability to achieve conditional control through external optogenetic or chemogenetic triggers. Genetic code expansion provides a unique solution by allowing for site-specific installation of functionally masked unnatural amino acids (UAAs) into proteins, such as enzymes and enzyme substrates, rendering them inert until rapid activation through exposure to light or small molecules. Here, we summarize the most recent advances harnessing this methodology to study various forms of PTMs, as well as generalizable approaches to externally control nodes-of-interest in PTM networks.
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Affiliation(s)
- Wenyuan Zhou
- Department of Chemistry, University of Pittsburgh, Pittsburgh, PA, 15260, USA
| | - Alexander Deiters
- Department of Chemistry, University of Pittsburgh, Pittsburgh, PA, 15260, USA.
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Tian Y, Fang M, Lin Q. Intracellular bioorthogonal labeling of glucagon receptor via tetrazine ligation. Bioorg Med Chem 2021; 43:116256. [PMID: 34153838 DOI: 10.1016/j.bmc.2021.116256] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2021] [Revised: 05/29/2021] [Accepted: 05/31/2021] [Indexed: 01/21/2023]
Abstract
The third intracellular loop (ICL3) in the cytosolic face of glucagon receptor (GCGR) experiences significant conformational transition during receptor activation. It thus offers an attractive site for the introduction of organic fluorophores in our efforts to construct fluorescence-based GPCR biosensors. Herein, we report our confocal microscopic study of intracellular fluorescent labeling of ICL3 using a bioorthogonal chemistry strategy. Our approach involves the site-specific introduction of a strained alkene amino acid into the ICL3 through genetic code expansion, followed by a highly specific inverse electron-demand Diels-Alder reaction with the fluorescent tetrazine probes. Among the three strained alkene amino acids examined, both SphK and 2'-aTCOK offered successful fluorescent labeling of GCGR ICL3 with the appropriate tetrazine probes. At the same time, 4'-TCOK gave high background fluorescence due to its intracellular retention. The fluorescent tetrazine probes were designed following a computational model for background-free intracellular fluorescent labeling; however, their performance varied significantly in live-cell imaging as the strong non-specific signals interfered with the specific ones. Among all GCGR ICL3 mutants bearing a strained alkene, the H339SphK/2'-aTCOK mutants provided the best reaction partners for the BODIPY-Tz1/4 reagents in the bioorthogonal labeling reactions. The results from this study highlight the challenges in identifying bioorthogonal reactant pairs suitable for intracellular labeling of low-abundance receptors in live-cell imaging studies.
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Affiliation(s)
- Yulin Tian
- Department of Chemistry, State University of New York at Buffalo, Buffalo, NY 14260-3000, United States; Institute of Materia Medica, Peking Union Medical College and Chinese Academy of Medical Sciences, Beijing, China
| | - Ming Fang
- Department of Chemistry, State University of New York at Buffalo, Buffalo, NY 14260-3000, United States
| | - Qing Lin
- Department of Chemistry, State University of New York at Buffalo, Buffalo, NY 14260-3000, United States.
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Tharp JM, Walker JA, Söll D, Schepartz A. Initiating protein synthesis with noncanonical monomers in vitro and in vivo. Methods Enzymol 2021; 656:495-519. [PMID: 34325796 DOI: 10.1016/bs.mie.2021.05.002] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
With few exceptions, ribosomal protein synthesis begins with methionine (or its derivative N-formyl-methionine) across all domains of life. The role of methionine as the initiating amino acid is dictated by the unique structure of its cognate tRNA known as tRNAfMet. By mis-acylating tRNAfMet, we and others have shown that protein synthesis can be initiated with a variety of canonical and noncanonical amino acids both in vitro and in vivo. Furthermore, because the α-amine of the initiating amino acid is not required for peptide bond formation, translation can be initiated with a variety of structurally disparate carboxylic acids that bear little resemblance to traditional α-amino acids. Herein, we provide a detailed protocol to initiate in vitro protein synthesis with substituted benzoic acid and 1,3-dicarbonyl compounds. These moieties are introduced at the N-terminus of peptides by mis-acylated tRNAfMet, prepared by flexizyme-catalyzed tRNA acylation. In addition, we describe a protocol to initiate in vivo protein synthesis with aromatic noncanonical amino acids (ncAAs). This method relies on an engineered chimeric initiator tRNA that is acylated with ncAAs by an orthogonal aminoacyl-tRNA synthetase. Together, these systems are useful platforms for producing N-terminally modified proteins and for engineering the protein synthesis machinery of Escherichia coli to accept additional nonproteinogenic carboxylic acid monomers.
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Galles GD, Infield DT, Mehl RA, Ahern CA. Selection and validation of orthogonal tRNA/synthetase pairs for the encoding of unnatural amino acids across kingdoms. Methods Enzymol 2021; 654:3-18. [PMID: 34120719 DOI: 10.1016/bs.mie.2021.03.009] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
As an increasing number of protein structures are resolved at atomic and near-atomic resolution, conventional amino acid mutagenesis may be insufficient to test many mechanistic hypotheses. As a result, the development of new tRNA/aminoacyl-tRNA synthetase (aaRS) pairs has become an important tool for determining intricate molecular interactions and understanding protein structures. This chapter describes in detail the directed evolution of new tRNA/aaRS pairs in Escherichia coli for the incorporation of non-canonical amino acids (ncAA). Section 1 describes the selection of new tRNA/aaRS pairs in E. coli. Section 2 details the use of a synthetase to incorporate an ncAA into a mammalian cell line, and Sections 1 and 2 both include methods on the determination of synthetase efficacy and fidelity.
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Affiliation(s)
- Grace D Galles
- Department of Molecular Physiology and Biophysics, University of Iowa College of Medicine, Iowa City, IA, United States; Unnatural Protein Facility, Department of Biochemistry and Biophysics, Oregon State University, Corvallis, OR, United States
| | - Daniel T Infield
- Department of Molecular Physiology and Biophysics, University of Iowa College of Medicine, Iowa City, IA, United States
| | - Ryan A Mehl
- Unnatural Protein Facility, Department of Biochemistry and Biophysics, Oregon State University, Corvallis, OR, United States
| | - Christopher A Ahern
- Department of Molecular Physiology and Biophysics, University of Iowa College of Medicine, Iowa City, IA, United States.
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Abstract
Multiple reports over the past 2 years have provided the first complete structural analyses for the essential yeast chromatin remodeler, RSC, providing elaborate molecular details for its engagement with the nucleosome. However, there still remain gaps in resolution, particularly within the many RSC subunits that harbor histone binding domains. Solving contacts at these interfaces is crucial because they are regulated by posttranslational modifications that control remodeler binding modes and function. Modifications are dynamic in nature often corresponding to transcriptional activation states and cell cycle stage, highlighting not only a need for enriched spatial resolution but also temporal understanding of remodeler engagement with the nucleosome. Our recent work sheds light on some of those gaps by exploring the binding interface between the RSC catalytic motor protein, Sth1, and the nucleosome, in the living nucleus. Using genetically encoded photo-activatable amino acids incorporated into histones of living yeast we are able to monitor the nucleosomal binding of RSC, emphasizing the regulatory roles of histone modifications in a spatiotemporal manner. We observe that RSC prefers to bind H2B SUMOylated nucleosomes in vivo and interacts with neighboring nucleosomes via H3K14ac. Additionally, we establish that RSC is constitutively bound to the nucleosome and is not ejected during mitotic chromatin compaction but alters its binding mode as it progresses through the cell cycle. Our data offer a renewed perspective on RSC mechanics under true physiological conditions.
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Affiliation(s)
- Heinz Neumann
- Department of Structural Biochemistry, Max-Planck-Institute of Molecular Physiology, Otto-Hahn-Strasse 11, 44227, Dortmund, Germany. .,Department of Chemical Engineering and Biotechnology, University of Applied Sciences Darmstadt, Stephanstrasse 7, 64295, Darmstadt, Germany.
| | - Bryan J Wilkins
- Department of Chemistry and Biochemistry, Manhattan College, 4513 Manhattan College Parkway, Bronx, NY, 10471, USA.
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Abstract
Lysine acetylation is a ubiquitous modification permeating the proteomes of organisms from all domains of life. Lysine deacetylases (KDACs) reverse this modification by following two fundamentally different enzymatic mechanisms, which differ mainly by the need for NAD+ as stoichiometric co-substrate. KDACs are often found as catalytic subunit in protein complexes involved in cell cycle regulation, chromatin organization and transcription. Their promiscuity with respect to sequence context and type of lysine acylation convolutes the network of functional and physical connections.Here we present an efficient selection method for KDACs in E. coli, which allows for the creation of acyl-type specific KDAC variants, which greatly facilitate the investigation of their physiological function . The selection system builds on the incorporation of acylated lysines by genetic code expansion in reporter enzymes with essential lysine residues. We describe the creation of KDAC mutant libraries by saturation mutagenesis of active site residues, the isolation of individual mutants from this library using the selection system, and their biochemical characterization with acylated firefly luciferase.
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Affiliation(s)
- Martin Spinck
- Department of Structural Biochemistry, Max-Planck-Institute of Molecular Physiology, Dortmund, Germany
| | - Maria Ecke
- Department of Structural Biochemistry, Max-Planck-Institute of Molecular Physiology, Dortmund, Germany
| | - Damian Schiller
- Department of Structural Biochemistry, Max-Planck-Institute of Molecular Physiology, Dortmund, Germany
| | - Heinz Neumann
- Department of Structural Biochemistry, Max-Planck-Institute of Molecular Physiology, Dortmund, Germany.
- Department of Chemical Engineering and Biotechnology, University of Applied Sciences, Darmstadt, Germany.
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