1
|
Modak A, Kilic Z, Chattrakun K, Terry DS, Kalathur RC, Blanchard SC. Single-Molecule Imaging of Integral Membrane Protein Dynamics and Function. Annu Rev Biophys 2024; 53:427-453. [PMID: 39013028 DOI: 10.1146/annurev-biophys-070323-024308] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/18/2024]
Abstract
Integral membrane proteins (IMPs) play central roles in cellular physiology and represent the majority of known drug targets. Single-molecule fluorescence and fluorescence resonance energy transfer (FRET) methods have recently emerged as valuable tools for investigating structure-function relationships in IMPs. This review focuses on the practical foundations required for examining polytopic IMP function using single-molecule FRET (smFRET) and provides an overview of the technical and conceptual frameworks emerging from this area of investigation. In this context, we highlight the utility of smFRET methods to reveal transient conformational states critical to IMP function and the use of smFRET data to guide structural and drug mechanism-of-action investigations. We also identify frontiers where progress is likely to be paramount to advancing the field.
Collapse
Affiliation(s)
- Arnab Modak
- Department of Structural Biology, St. Jude Children's Research Hospital, Memphis, Tennessee, USA; , , , , ,
| | - Zeliha Kilic
- Department of Structural Biology, St. Jude Children's Research Hospital, Memphis, Tennessee, USA; , , , , ,
| | - Kanokporn Chattrakun
- Department of Structural Biology, St. Jude Children's Research Hospital, Memphis, Tennessee, USA; , , , , ,
| | - Daniel S Terry
- Department of Structural Biology, St. Jude Children's Research Hospital, Memphis, Tennessee, USA; , , , , ,
| | - Ravi C Kalathur
- Department of Structural Biology, St. Jude Children's Research Hospital, Memphis, Tennessee, USA; , , , , ,
| | - Scott C Blanchard
- Department of Structural Biology, St. Jude Children's Research Hospital, Memphis, Tennessee, USA; , , , , ,
- Department of Chemical Biology & Therapeutics, St. Jude Children's Research Hospital, Memphis, Tennessee, USA
| |
Collapse
|
2
|
Luu T, Gristwood K, Knight JC, Jörg M. Click Chemistry: Reaction Rates and Their Suitability for Biomedical Applications. Bioconjug Chem 2024; 35:715-731. [PMID: 38775705 PMCID: PMC11191409 DOI: 10.1021/acs.bioconjchem.4c00084] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2024] [Revised: 05/09/2024] [Accepted: 05/09/2024] [Indexed: 06/21/2024]
Abstract
Click chemistry has become a commonly used synthetic method due to the simplicity, efficiency, and high selectivity of this class of chemical reactions. Since their initial discovery, further click chemistry methods have been identified and added to the toolbox of click chemistry reactions for biomedical applications. However, selecting the most suitable reaction for a specific application is often challenging, as multiple factors must be considered, including selectivity, reactivity, biocompatibility, and stability. Thus, this review provides an overview of the benefits and limitations of well-established click chemistry reactions with a particular focus on the importance of considering reaction rates, an often overlooked criterion with little available guidance. The importance of understanding each click chemistry reaction beyond simply the reaction speed is discussed comprehensively with reference to recent biomedical research which utilized click chemistry. This review aims to provide a practical resource for researchers to guide the selection of click chemistry classes for different biomedical applications.
Collapse
Affiliation(s)
- Tracey Luu
- Medicinal
Chemistry Theme, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Victoria 3052, Australia
| | - Katie Gristwood
- School
of Natural & Environmental Sciences, Newcastle University, Newcastle Upon Tyne NE1 7RU, U.K.
| | - James C. Knight
- School
of Natural & Environmental Sciences, Newcastle University, Newcastle Upon Tyne NE1 7RU, U.K.
| | - Manuela Jörg
- Medicinal
Chemistry Theme, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Victoria 3052, Australia
- School
of Natural & Environmental Sciences, Newcastle University, Newcastle Upon Tyne NE1 7RU, U.K.
| |
Collapse
|
3
|
Mehak, Singh G, Singh R, Singh G, Stanzin J, Singh H, Kaur G, Singh J. Clicking in harmony: exploring the bio-orthogonal overlap in click chemistry. RSC Adv 2024; 14:7383-7413. [PMID: 38433942 PMCID: PMC10906366 DOI: 10.1039/d4ra00494a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2024] [Accepted: 02/19/2024] [Indexed: 03/05/2024] Open
Abstract
In the quest to scrutinize and modify biological systems, the global research community has continued to explore bio-orthogonal click reactions, a set of reactions exclusively targeting non-native molecules within biological systems. These methodologies have brought about a paradigm shift, demonstrating the feasibility of artificial chemical reactions occurring on cellular surfaces, in the cell cytosol, or within the body - an accomplishment challenging to achieve with the majority of conventional chemical reactions. This review delves into the principles of bio-orthogonal click chemistry, contrasting metal-catalyzed and metal-free reactions of bio-orthogonal nature. It comprehensively explores mechanistic details and applications, highlighting the versatility and potential of this methodology in diverse scientific contexts, from cell labelling to biosensing and polymer synthesis. Researchers globally continue to advance this powerful tool for precise and selective manipulation of biomolecules in complex biological systems.
Collapse
Affiliation(s)
- Mehak
- School of Chemical Engineering and Physical Sciences, Lovely Professional University Phagwara-144411 Punjab India
| | - Gurleen Singh
- School of Chemical Engineering and Physical Sciences, Lovely Professional University Phagwara-144411 Punjab India
| | - Riddima Singh
- School of Chemical Engineering and Physical Sciences, Lovely Professional University Phagwara-144411 Punjab India
| | - Gurjaspreet Singh
- Department of Chemistry and Centre of Advanced Studies in Chemistry, Panjab University Chandigarh-160014 India
| | - Jigmat Stanzin
- Department of Chemistry and Centre of Advanced Studies in Chemistry, Panjab University Chandigarh-160014 India
| | - Harminder Singh
- School of Chemical Engineering and Physical Sciences, Lovely Professional University Phagwara-144411 Punjab India
| | - Gurpreet Kaur
- Department of Chemistry, Gujranwala Guru Nanak Khalsa College Civil Lines Ludhiana-141001 Punjab India
| | - Jandeep Singh
- School of Chemical Engineering and Physical Sciences, Lovely Professional University Phagwara-144411 Punjab India
| |
Collapse
|
4
|
Lin CC, Frahm E, Afolabi FO. Orthogonally Crosslinked Gelatin-Norbornene Hydrogels for Biomedical Applications. Macromol Biosci 2024; 24:e2300371. [PMID: 37748778 PMCID: PMC10922053 DOI: 10.1002/mabi.202300371] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2023] [Revised: 09/19/2023] [Indexed: 09/27/2023]
Abstract
The thiol-norbornene photo-click reaction has exceptionally fast crosslinking efficiency compared with chain-growth polymerization at equivalent macromer contents. The orthogonal reactivity between norbornene and thiol/tetrazine permits crosslinking of synthetic and naturally derived macromolecules with modularity, including poly(ethylene glycol) (PEG)-norbornene (PEGNB), gelatin-norbornene (GelNB), among others. For example, collagen-derived gelatin contains both cell adhesive motifs (e.g., Arg-Gly-Asp or RGD) and protease-labile sequences, making it an ideal macromer for forming cell-laden hydrogels. First reported in 2014, GelNB is increasingly used in orthogonal crosslinking of biomimetic matrices in various applications. GelNB can be crosslinked into hydrogels using multi-functional thiol linkers (e.g., dithiothreitol (DTT) or PEG-tetra-thiol (PEG4SH) via visible light or longwave ultraviolet (UV) light step-growth thiol-norbornene reaction or through an enzyme-mediated crosslinking (i.e., horseradish peroxidase, HRP). GelNB-based hydrogels can also be modularly crosslinked with tetrazine-bearing macromers via inverse electron-demand Diels-Alder (iEDDA) click reaction. This review surveys the various methods for preparing GelNB macromers, the crosslinking mechanisms of GelNB-based hydrogels, and their applications in cell and tissue engineering, including crosslinking of dynamic matrices, disease modeling, and tissue regeneration, delivery of therapeutics, as well as bioprinting and biofabrication.
Collapse
Affiliation(s)
- Chien-Chi Lin
- Department of Biomedical Engineering, Purdue School of Engineering & Technology, Indiana University-Purdue University Indianapolis, Indianapolis, IN. 46202. USA
| | - Ellen Frahm
- Department of Biomedical Engineering, Purdue School of Engineering & Technology, Indiana University-Purdue University Indianapolis, Indianapolis, IN. 46202. USA
| | - Favor O. Afolabi
- Department of Biomedical Engineering, Purdue School of Engineering & Technology, Indiana University-Purdue University Indianapolis, Indianapolis, IN. 46202. USA
| |
Collapse
|
5
|
Šlachtová V, Chovanec M, Rahm M, Vrabel M. Bioorthogonal Chemistry in Cellular Organelles. Top Curr Chem (Cham) 2023; 382:2. [PMID: 38103067 PMCID: PMC10725395 DOI: 10.1007/s41061-023-00446-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2023] [Accepted: 11/12/2023] [Indexed: 12/17/2023]
Abstract
While bioorthogonal reactions are routinely employed in living cells and organisms, their application within individual organelles remains limited. In this review, we highlight diverse examples of bioorthogonal reactions used to investigate the roles of biomolecules and biological processes as well as advanced imaging techniques within cellular organelles. These innovations hold great promise for therapeutic interventions in personalized medicine and precision therapies. We also address existing challenges related to the selectivity and trafficking of subcellular dynamics. Organelle-targeted bioorthogonal reactions have the potential to significantly advance our understanding of cellular organization and function, provide new pathways for basic research and clinical applications, and shape the direction of cell biology and medical research.
Collapse
Affiliation(s)
- Veronika Šlachtová
- Department of Bioorganic and Medicinal Chemistry, Institute of Organic Chemistry and Biochemistry of the Czech Academy of Sciences, Flemingovo náměstí 2, 166 10, Prague 6, Czech Republic
| | - Marek Chovanec
- Department of Bioorganic and Medicinal Chemistry, Institute of Organic Chemistry and Biochemistry of the Czech Academy of Sciences, Flemingovo náměstí 2, 166 10, Prague 6, Czech Republic
- University of Chemistry and Technology, Technická 5, 166 28, Prague 6, Czech Republic
| | - Michal Rahm
- Department of Bioorganic and Medicinal Chemistry, Institute of Organic Chemistry and Biochemistry of the Czech Academy of Sciences, Flemingovo náměstí 2, 166 10, Prague 6, Czech Republic
- University of Chemistry and Technology, Technická 5, 166 28, Prague 6, Czech Republic
| | - Milan Vrabel
- Department of Bioorganic and Medicinal Chemistry, Institute of Organic Chemistry and Biochemistry of the Czech Academy of Sciences, Flemingovo náměstí 2, 166 10, Prague 6, Czech Republic.
| |
Collapse
|
6
|
Rieger L, Pfeuffer B, Wagenknecht HA. Metabolic labelling of DNA in cells by means of the "photoclick" reaction triggered by visible light. RSC Chem Biol 2023; 4:1037-1042. [PMID: 38033731 PMCID: PMC10685802 DOI: 10.1039/d3cb00150d] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2023] [Accepted: 08/30/2023] [Indexed: 12/02/2023] Open
Abstract
Two pyrene-tetrazole conjugates were synthesized as photoreactive chromophores that allow for the first time the combination of metabolic labelling of DNA in cells and subsequent bioorthogonal "photoclick" modification triggered by visible light. Two strained alkenes and three alkene-modified nucleosides were used as reactive counterparts and revealed no major differences in their "photoclick" reactivity. This is a significant advantage because it allows 5-vinyl-2'-deoxyuridine to be applied as the smallest possible alkene-modified nucleoside for metabolic labelling of DNA in cells. Both pyrene-tetrazole conjugates show fluorogenicity during the "photoclick" reactions, which is a second advantage for cellular imaging. Living HeLa cells were incubated with 5-vinyl-2'-deoxyuridine for 48 h to ensure one cell division. After fixation, the newly synthesized genomic DNA was successfully labelled by irradiation with visible light at 405 nm and 450 nm. This method is an attractive tool for the visualization of genomic DNA in cells with full spatiotemporal control by the use of visible light as a reaction trigger.
Collapse
Affiliation(s)
- Lisa Rieger
- Institute of Organic Chemistry, Karlsruhe Institute of Technology (KIT), Fritz-Haber-Weg 6 Karlsruhe 76131 Germany
| | - Bastian Pfeuffer
- Institute of Organic Chemistry, Karlsruhe Institute of Technology (KIT), Fritz-Haber-Weg 6 Karlsruhe 76131 Germany
| | - Hans-Achim Wagenknecht
- Institute of Organic Chemistry, Karlsruhe Institute of Technology (KIT), Fritz-Haber-Weg 6 Karlsruhe 76131 Germany
| |
Collapse
|
7
|
Manoharan A, Jayan J, Rangarajan TM, Bose K, Benny F, Ipe RS, Kumar S, Kukreti N, Abdelgawad MA, Ghoneim MM, Kim H, Mathew B. "Click Chemistry": An Emerging Tool for Developing a New Class of Structural Motifs against Various Neurodegenerative Disorders. ACS OMEGA 2023; 8:44437-44457. [PMID: 38046293 PMCID: PMC10688180 DOI: 10.1021/acsomega.3c04960] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/11/2023] [Revised: 10/24/2023] [Accepted: 10/26/2023] [Indexed: 12/05/2023]
Abstract
Click chemistry is a set of easy, atom-economical reactions that are often utilized to combine two desired chemical entities. Click chemistry accelerates lead identification and optimization, reduces the complexity of chemical synthesis, and delivers extremely high yields without undesirable byproducts. The most well-known click chemistry reaction is the 1,3-dipolar cycloaddition of azides and alkynes to form 1,2,3-triazoles. The resulting 1,2,3-triazoles can serve as both bioisosteres and linkers, leading to an increase in their use in the field of drug discovery. The current Review focuses on the use of click chemistry to identify new molecules for treating neurodegenerative diseases and in other areas such as peptide targeting and the quantification of biomolecules.
Collapse
Affiliation(s)
- Amritha Manoharan
- Department
of Pharmaceutical Chemistry, Amrita School of Pharmacy, Amrita Vishwa
Vidyapeetham, AIMS Health Sciences Campus, Kochi 682 041, India
| | - Jayalakshmi Jayan
- Department
of Pharmaceutical Chemistry, Amrita School of Pharmacy, Amrita Vishwa
Vidyapeetham, AIMS Health Sciences Campus, Kochi 682 041, India
| | - T. M. Rangarajan
- Department
of Chemistry, Sri Venkateswara College, University of Delhi, New Delhi 110021, India
| | - Kuntal Bose
- Department
of Pharmaceutical Chemistry, Amrita School of Pharmacy, Amrita Vishwa
Vidyapeetham, AIMS Health Sciences Campus, Kochi 682 041, India
| | - Feba Benny
- Department
of Pharmaceutical Chemistry, Amrita School of Pharmacy, Amrita Vishwa
Vidyapeetham, AIMS Health Sciences Campus, Kochi 682 041, India
| | - Reshma Susan Ipe
- Department
of Pharmaceutical Chemistry, Amrita School of Pharmacy, Amrita Vishwa
Vidyapeetham, AIMS Health Sciences Campus, Kochi 682 041, India
| | - Sunil Kumar
- Department
of Pharmaceutical Chemistry, Amrita School of Pharmacy, Amrita Vishwa
Vidyapeetham, AIMS Health Sciences Campus, Kochi 682 041, India
| | - Neelima Kukreti
- School
of Pharmacy, Graphic Era Hill University, Dehradun, Uttarakhand 248007, India
| | - Mohamed A. Abdelgawad
- Department
of Pharmaceutical Chemistry, College of Pharmacy, Jouf University, Sakaka 72341, Saudi Arabia
- Department
of Pharmaceutical Organic Chemistry, Faculty of Pharmacy, Beni-Suef University, Beni-Suef 62514, Egypt
| | - Mohammed M. Ghoneim
- Department
of Pharmacy Practice, College of Pharmacy, AlMaarefa University, Ad Diriyah 13713, Saudi Arabia
| | - Hoon Kim
- Department
of Pharmacy, and Research Institute of Life Pharmaceutical Sciences, Sunchon National University, Suncheon 57922, Republic of Korea
| | - Bijo Mathew
- Department
of Pharmaceutical Chemistry, Amrita School of Pharmacy, Amrita Vishwa
Vidyapeetham, AIMS Health Sciences Campus, Kochi 682 041, India
| |
Collapse
|
8
|
Stone DJ, Macias-Contreras M, Crist SM, Bucag CFT, Seo G, Zhu L. SNAP-tagging live cells via chelation-assisted copper-catalyzed azide-alkyne cycloaddition. Org Biomol Chem 2023; 21:7419-7436. [PMID: 37665276 DOI: 10.1039/d3ob01003a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/05/2023]
Abstract
SNAP-tag is a single-turnover enzyme that has become a powerful tool, hence a popular choice, of targeted cellular protein labeling. Three SNAP-tag substrates that carry the copper-chelating 2-picolyl azide moiety are prepared, one of which has an unconventional 5-pyridylmethyl-substituted guanine structure, rather than the usual benzylguanine that is optimized to be accepted by SNAP-tag. All three substrates are effective in transferring a 2-picolyl azide moiety to SNAP-tag in live cells under conventional labeling conditions (30-minute incubation of cells with labeling reagents at 37 °C under 5% CO2). Live cells that are decorated with chelating azido groups on the extracellular side of membranes undergo copper-catalyzed azide-alkyne cycloaddition (CuAAC) with an ethynyl-functionalized fluorophore to accomplish membrane protein labeling by a fluorescent dye. The chelation-assisted CuAAC labeling step is rapid (<1 minute) with a relatively low dose of the copper catalyst (20 μM), and consequently exerts no ill effect on the labeled cells. A SNAP-tag substrate that carries a non-chelating azide moiety, on the other hand, fails to produce satisfactory labeling under the same constraints. The rapid, live cell-compatible SNAP-tag/chelation-assisted CuAAC two-step method expands the utility of SNAP-tag in protein labeling applications.
Collapse
Affiliation(s)
- Daniel J Stone
- Department of Chemistry and Biochemistry, Florida State University, 95 Chieftan Way, Tallahassee, FL 32306-4390, USA.
| | - Miguel Macias-Contreras
- Department of Chemistry and Biochemistry, Florida State University, 95 Chieftan Way, Tallahassee, FL 32306-4390, USA.
| | - Shaun M Crist
- Department of Chemistry and Biochemistry, Florida State University, 95 Chieftan Way, Tallahassee, FL 32306-4390, USA.
| | - Christelle F T Bucag
- Department of Chemistry and Biochemistry, Florida State University, 95 Chieftan Way, Tallahassee, FL 32306-4390, USA.
| | - Gwimoon Seo
- Institute of Molecular Biophysics, Florida State University, 91 Chieftan Way, Tallahassee, FL 32306-4380, USA
| | - Lei Zhu
- Department of Chemistry and Biochemistry, Florida State University, 95 Chieftan Way, Tallahassee, FL 32306-4390, USA.
| |
Collapse
|
9
|
Scinto SL, Reagle TR, Fox JM. Affinity Bioorthogonal Chemistry (ABC) Tags for Site-Selective Conjugation, On-Resin Protein-Protein Coupling, and Purification of Protein Conjugates. Angew Chem Int Ed Engl 2022; 61:e202207661. [PMID: 36058881 PMCID: PMC10029600 DOI: 10.1002/anie.202207661] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2022] [Indexed: 11/12/2022]
Abstract
The site-selective functionalization of proteins has broad application in chemical biology, but can be limited when mixtures result from incomplete conversion or the formation of protein containing side products. It is shown here that when proteins are covalently tagged with pyridyl-tetrazines, the nickel-iminodiacetate (Ni-IDA) resins commonly used for His-tags can be directly used for protein affinity purification. These Affinity Bioorthogonal Chemistry (ABC) tags serve a dual role by enabling affinity-based protein purification while maintaining rapid kinetics in bioorthogonal reactions. ABC-tagging works with a range of site-selective bioconjugation methods with proteins tagged at the C-terminus, N-terminus or at internal positions. ABC-tagged proteins can also be purified from complex mixtures including cell lysate. The combination of site-selective conjugation and clean-up with ABC-tagged proteins also allows for facile on-resin reactions to provide protein-protein conjugates.
Collapse
Affiliation(s)
- Samuel L Scinto
- Department of Chemistry and Biochemistry, University of Delaware, Ammon Pinizzotto Biopharmaceutical Innovation Center, Newark, DE 19713, USA
| | - Tyler R Reagle
- Department of Chemistry and Biochemistry, University of Delaware, Ammon Pinizzotto Biopharmaceutical Innovation Center, Newark, DE 19713, USA
| | - Joseph M Fox
- Department of Chemistry and Biochemistry, University of Delaware, Ammon Pinizzotto Biopharmaceutical Innovation Center, Newark, DE 19713, USA
| |
Collapse
|
10
|
Kondengadan SM, Bansal S, Yang C, Liu D, Fultz Z, Wang B. Click chemistry and drug delivery: A bird’s-eye view. Acta Pharm Sin B 2022; 13:1990-2016. [DOI: 10.1016/j.apsb.2022.10.015] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2022] [Revised: 10/12/2022] [Accepted: 10/12/2022] [Indexed: 11/01/2022] Open
|
11
|
Ma X, Wei B, Wang E. Efficient incorporation of p-azido-l-phenylalanine into the protein using organic solvents. Protein Expr Purif 2022; 200:106158. [PMID: 36007861 DOI: 10.1016/j.pep.2022.106158] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2022] [Revised: 08/12/2022] [Accepted: 08/17/2022] [Indexed: 11/30/2022]
Abstract
Azide, the most used photo-crosslinking group, facilitates the analysis of protein structure and function. This group is particularly useful when photochemically label antibodies and examine protein-protein interactions. The use of the expanded genetic code technique allows the special labeling of the functional azide group in proteins by adding the unnatural amino acid (UAA), p-azido-l-phenylalanine (AzF), in response to the amber codon during translation. However, a low UAA uptake rate due to mass transfer resistance in the cell membrane may lead to the early termination of the full-length protein. This study reports a general method for the efficient in vivo incorporation of AzF into the target protein by improving cell permeability using organic solvents. As expected, the yield of the full-length protein was significantly increased, which indicated that the AzF uptake was greatly improved due to the addition of organic solvents. Our method can serve as a good reference for improving the genetic incorporation of other kinds of UAAs into proteins.
Collapse
Affiliation(s)
- Xiaofeng Ma
- Department of Gynecology and Obstetrics, The Second Hospital of Anhui Medical University, Hefei, Anhui, 230601, China
| | - Bing Wei
- Department of Gynecology and Obstetrics, The Second Hospital of Anhui Medical University, Hefei, Anhui, 230601, China
| | - Enlin Wang
- The College of Life Science, Nankai University, Tianjin, 300071, China.
| |
Collapse
|
12
|
Pei X, Luo Z, Qiao L, Xiao Q, Zhang P, Wang A, Sheldon RA. Putting precision and elegance in enzyme immobilisation with bio-orthogonal chemistry. Chem Soc Rev 2022; 51:7281-7304. [PMID: 35920313 DOI: 10.1039/d1cs01004b] [Citation(s) in RCA: 21] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The covalent immobilisation of enzymes generally involves the use of highly reactive crosslinkers, such as glutaraldehyde, to couple enzyme molecules to each other or to carriers through, for example, the free amino groups of lysine residues, on the enzyme surface. Unfortunately, such methods suffer from a lack of precision. Random formation of covalent linkages with reactive functional groups in the enzyme leads to disruption of the three dimensional structure and accompanying activity losses. This review focuses on recent advances in the use of bio-orthogonal chemistry in conjunction with rec-DNA to affect highly precise immobilisation of enzymes. In this way, cost-effective combination of production, purification and immobilisation of an enzyme is achieved, in a single unit operation with a high degree of precision. Various bio-orthogonal techniques for putting this precision and elegance into enzyme immobilisation are elaborated. These include, for example, fusing (grafting) peptide or protein tags to the target enzyme that enable its immobilisation in cell lysate or incorporating non-standard amino acids that enable the application of bio-orthogonal chemistry.
Collapse
Affiliation(s)
- Xiaolin Pei
- College of Materials, Chemistry and Chemical Engineering, Key Laboratory of Organosilicon Chemistry and Material Technology, Ministry of Education, Key Laboratory of Organosilicon Material Technology, Hangzhou Normal University, Zhejiang Province, Hangzhou, 311121, Zhejiang, P. R. China
| | - Zhiyuan Luo
- College of Materials, Chemistry and Chemical Engineering, Key Laboratory of Organosilicon Chemistry and Material Technology, Ministry of Education, Key Laboratory of Organosilicon Material Technology, Hangzhou Normal University, Zhejiang Province, Hangzhou, 311121, Zhejiang, P. R. China
| | - Li Qiao
- College of Materials, Chemistry and Chemical Engineering, Key Laboratory of Organosilicon Chemistry and Material Technology, Ministry of Education, Key Laboratory of Organosilicon Material Technology, Hangzhou Normal University, Zhejiang Province, Hangzhou, 311121, Zhejiang, P. R. China
| | - Qinjie Xiao
- College of Materials, Chemistry and Chemical Engineering, Key Laboratory of Organosilicon Chemistry and Material Technology, Ministry of Education, Key Laboratory of Organosilicon Material Technology, Hangzhou Normal University, Zhejiang Province, Hangzhou, 311121, Zhejiang, P. R. China
| | - Pengfei Zhang
- College of Materials, Chemistry and Chemical Engineering, Key Laboratory of Organosilicon Chemistry and Material Technology, Ministry of Education, Key Laboratory of Organosilicon Material Technology, Hangzhou Normal University, Zhejiang Province, Hangzhou, 311121, Zhejiang, P. R. China
| | - Anming Wang
- College of Materials, Chemistry and Chemical Engineering, Key Laboratory of Organosilicon Chemistry and Material Technology, Ministry of Education, Key Laboratory of Organosilicon Material Technology, Hangzhou Normal University, Zhejiang Province, Hangzhou, 311121, Zhejiang, P. R. China
| | - Roger A Sheldon
- Molecular Sciences Institute, School of Chemistry, University of the Witwatersrand, PO Wits, 2050, Johannesburg, South Africa. .,Department of Biotechnology, Section BOC, Delft University of Technology, van der Maasweg 9, 2629 HZ Delft, The Netherlands
| |
Collapse
|
13
|
García-Aznar P, Escorihuela J. Computational insights into the inverse electron-demand Diels-Alder reaction of norbornenes with 1,2,4,5-tetrazines: norbornene substituents' effects on the reaction rate. Org Biomol Chem 2022; 20:6400-6412. [PMID: 35876298 DOI: 10.1039/d2ob01121b] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The study of the reaction rates and mechanism of click chemistry reactions still remains an interesting challenge in organic chemistry. In this regard, the inverse electron demand Diels-Alder (IEDDA) reaction represents a promising metal-free alternative with enhanced reaction rates compared to other reactions of the click chemistry toolbox. Among the different types of dienophiles used in the IEDDA reactions, norbornenes have been widely used given their high stability and fast reaction rates. The inverse electron-demand Diels Alder reaction of 3,6-dipyridin-2-yl-1,2,4,5-tetrazine with a series of norbornene derivatives was studied with quantum mechanical calculations at the M06-2X/6-311+G(d,p) level of theory. The theoretical predictions were confirmed with the experimental data and analyzed with the use of the distortion/interaction model. The obtained results will help in obtaining a better understanding of the factors that affect the relative cycloaddition rates of norbornenes with tetrazines, which are crucial for selectively tuning their efficacy.
Collapse
Affiliation(s)
- Pablo García-Aznar
- Departamento de Química Orgánica, Facultad de Farmacia, Universitat de València, Avda. Vicente Andrés Estellés, s/n, Burjassot 46100, València, Spain.
| | - Jorge Escorihuela
- Departamento de Química Orgánica, Facultad de Farmacia, Universitat de València, Avda. Vicente Andrés Estellés, s/n, Burjassot 46100, València, Spain.
| |
Collapse
|
14
|
Melis DR, Burgoyne AR, Ooms M, Gasser G. Bifunctional chelators for radiorhenium: past, present and future outlook. RSC Med Chem 2022; 13:217-245. [PMID: 35434629 PMCID: PMC8942221 DOI: 10.1039/d1md00364j] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2021] [Accepted: 01/14/2022] [Indexed: 01/16/2023] Open
Abstract
Targeted radionuclide therapy (TRNT) is an ever-expanding field of nuclear medicine that provides a personalised approach to cancer treatment while limiting toxicity to normal tissues. It involves the radiolabelling of a biological targeting vector with an appropriate therapeutic radionuclide, often facilitated by the use of a bifunctional chelator (BFC) to stably link the two entities. The radioisotopes of rhenium, 186Re (t 1/2 = 90 h, 1.07 MeV β-, 137 keV γ (9%)) and 188Re (t 1/2 = 16.9 h, 2.12 MeV β-, 155 keV γ (15%)), are particularly attractive for radiotherapy because of their convenient and high-abundance β--particle emissions as well as their imageable γ-emissions and chemical similarity to technetium. As a transition metal element with multiple oxidation states and coordination numbers accessible for complexation, there is great opportunity available when it comes to developing novel BFCs for rhenium. The purpose of this review is to provide a recap on some of the past successes and failings, as well as show some more current efforts in the design of BFCs for 186/188Re. Future use of these radionuclides for radiotherapy depends on their cost-effective availability and this will also be discussed. Finally, bioconjugation strategies for radiolabelling biomolecules with 186/188Re will be touched upon.
Collapse
Affiliation(s)
- Diana R Melis
- SCK CEN, Belgian Nuclear Research Centre Boeretang 200 BE-2400 Mol Belgium +1 865 341 1413 +32 14 33 32 83
- Chimie ParisTech, Laboratory for Inorganic Chemical Biology, PSL University F-75005 Paris France www.gassergroup.com +33 1 44 27 56 02
| | - Andrew R Burgoyne
- SCK CEN, Belgian Nuclear Research Centre Boeretang 200 BE-2400 Mol Belgium +1 865 341 1413 +32 14 33 32 83
| | - Maarten Ooms
- SCK CEN, Belgian Nuclear Research Centre Boeretang 200 BE-2400 Mol Belgium +1 865 341 1413 +32 14 33 32 83
| | - Gilles Gasser
- Chimie ParisTech, Laboratory for Inorganic Chemical Biology, PSL University F-75005 Paris France www.gassergroup.com +33 1 44 27 56 02
| |
Collapse
|
15
|
Bednar RM, Jana S, Kuppa S, Franklin R, Beckman J, Antony E, Cooley RB, Mehl RA. Genetic Incorporation of Two Mutually Orthogonal Bioorthogonal Amino Acids That Enable Efficient Protein Dual-Labeling in Cells. ACS Chem Biol 2021; 16:2612-2622. [PMID: 34590824 DOI: 10.1021/acschembio.1c00649] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
The ability to site-specifically modify proteins at multiple sites in vivo will enable the study of protein function in its native environment with unprecedented levels of detail. Here, we present a versatile two-step strategy to meet this goal involving site-specific encoding of two distinct noncanonical amino acids bearing bioorthogonal handles into proteins in vivo followed by mutually orthogonal labeling. This general approach, that we call dual encoding and labeling (DEAL), allowed us to efficiently encode tetrazine- and azide-bearing amino acids into a protein and demonstrate for the first time that the bioorthogonal labeling reactions with strained alkene and alkyne labels can function simultaneously and intracellularly with high yields when site-specifically encoded in a single protein. Using our DEAL system, we were able to perform topologically defined protein-protein cross-linking, intramolecular stapling, and site-specific installation of fluorophores all inside living Escherichia coli cells, as well as study the DNA-binding properties of yeast Replication Protein A in vitro. By enabling the efficient dual modification of proteins in vivo, this DEAL approach provides a tool for the characterization and engineering of proteins in vivo.
Collapse
Affiliation(s)
- Riley M. Bednar
- Department of Biochemistry and Biophysics, Oregon State University, 2011 Agricultural & Life Sciences Building, Corvallis, Oregon 97331-7305, United States
| | - Subhashis Jana
- Department of Biochemistry and Biophysics, Oregon State University, 2011 Agricultural & Life Sciences Building, Corvallis, Oregon 97331-7305, United States
| | - Sahiti Kuppa
- Department of Biochemistry and Molecular Biology, Saint Louis University School of Medicine, Edward A. Doisy Research Center, 1100 South Grand Blvd., St. Louis, Missouri 63104, United States
| | - Rachel Franklin
- Department of Biochemistry and Biophysics, Oregon State University, 2011 Agricultural & Life Sciences Building, Corvallis, Oregon 97331-7305, United States
| | - Joseph Beckman
- Department of Biochemistry and Biophysics, Oregon State University, 2011 Agricultural & Life Sciences Building, Corvallis, Oregon 97331-7305, United States
| | - Edwin Antony
- Department of Biochemistry and Molecular Biology, Saint Louis University School of Medicine, Edward A. Doisy Research Center, 1100 South Grand Blvd., St. Louis, Missouri 63104, United States
| | - Richard B. Cooley
- Department of Biochemistry and Biophysics, Oregon State University, 2011 Agricultural & Life Sciences Building, Corvallis, Oregon 97331-7305, United States
| | - Ryan A. Mehl
- Department of Biochemistry and Biophysics, Oregon State University, 2011 Agricultural & Life Sciences Building, Corvallis, Oregon 97331-7305, United States
| |
Collapse
|
16
|
van Hest J, Zheng G, Rotello VM. Bioorthogonal Chemistry and Bioconjugation: Synergistic Tools for Biology and Biomedicine. Bioconjug Chem 2021; 32:1409-1410. [PMID: 34323066 DOI: 10.1021/acs.bioconjchem.1c00355] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
|
17
|
Kaur J, Saxena M, Rishi N. An Overview of Recent Advances in Biomedical Applications of Click Chemistry. Bioconjug Chem 2021; 32:1455-1471. [PMID: 34319077 DOI: 10.1021/acs.bioconjchem.1c00247] [Citation(s) in RCA: 77] [Impact Index Per Article: 25.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Cu(I)-catalyzed azide-alkyne cycloaddition (CuAAC) is a modular and bio-orthogonal approach that is being adopted for the efficient synthesis of organic and bioorganic compounds. It leads to the selective formation of 1,4-disubstituted 1,2,3-triazole units connecting readily accessible building blocks via a stable and biocompatible linkage. The vast array of the bioconjugation applications of click chemistry has been attributed to its fast reaction kinetics, quantitative yields, minimal byproducts, and high chemospecificity and regioselectivity. These combined advantages make click reactions quite suitable for the lead identification and the development of pharmaceutical agents in the fields of medicinal chemistry and drug discovery. In this review, we have outlined the key aspects, the mechanistic details and merits and demerits of the click reaction. In addition, we have also discussed the recent pharmaceutical applications of click chemistry, ranging from the development of anticancer, antibacterial, and antiviral agents to that of biomedical imaging agents and clinical therapeutics.
Collapse
Affiliation(s)
- Jasleen Kaur
- Amity Institute of Virology and Immunology, Amity University, Noida 201313, Uttar Pradesh, India
| | - Mokshika Saxena
- Amity Institute of Virology and Immunology, Amity University, Noida 201313, Uttar Pradesh, India
| | - Narayan Rishi
- Amity Institute of Virology and Immunology, Amity University, Noida 201313, Uttar Pradesh, India
| |
Collapse
|
18
|
Hu Y, Schomaker JM. Recent Developments and Strategies for Mutually Orthogonal Bioorthogonal Reactions. Chembiochem 2021; 22:3254-3262. [PMID: 34261195 DOI: 10.1002/cbic.202100164] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2021] [Revised: 07/12/2021] [Indexed: 12/23/2022]
Abstract
Over the past decade, several different metal-free bioorthogonal reactions have been developed to enable simultaneous double-click labeling with minimal-to-no competing cross-reactivities; such transformations are termed 'mutually orthogonal'. More recently, several examples of successful triple ligation strategies have also been described. In this minireview, we discuss selected aspects of the development of orthogonal bioorthogonal reactions over the past decade, including general strategies to drive future innovations to achieve simultaneous, mutually orthogonal click reactions in one pot.
Collapse
Affiliation(s)
- Yun Hu
- Department of Chemistry, University of Wisconsin-Madison, 1101 University Avenue, Madison, WI, 53706, USA
| | - Jennifer M Schomaker
- Department of Chemistry, University of Wisconsin-Madison, 1101 University Avenue, Madison, WI, 53706, USA
| |
Collapse
|
19
|
Affiliation(s)
- Vincent Rigolot
- UMR 8576 CNRS Unité de Glycobiologie Structurale et Fonctionnelle Université de Lille Faculté des Sciences et Technologies Bât. C9, 59655 Villeneuve d'Ascq France
| | - Christophe Biot
- UMR 8576 CNRS Unité de Glycobiologie Structurale et Fonctionnelle Université de Lille Faculté des Sciences et Technologies Bât. C9, 59655 Villeneuve d'Ascq France
| | - Cedric Lion
- UMR 8576 CNRS Unité de Glycobiologie Structurale et Fonctionnelle Université de Lille Faculté des Sciences et Technologies Bât. C9, 59655 Villeneuve d'Ascq France
| |
Collapse
|
20
|
Rigolot V, Biot C, Lion C. To View Your Biomolecule, Click inside the Cell. Angew Chem Int Ed Engl 2021; 60:23084-23105. [PMID: 34097349 DOI: 10.1002/anie.202101502] [Citation(s) in RCA: 41] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2021] [Indexed: 12/13/2022]
Abstract
The surging development of bioorthogonal chemistry has profoundly transformed chemical biology over the last two decades. Involving chemical partners that specifically react together in highly complex biological fluids, this branch of chemistry now allows researchers to probe biomolecules in their natural habitat through metabolic labelling technologies. Chemical reporter strategies include metabolic glycan labelling, site-specific incorporation of unnatural amino acids in proteins, and post-synthetic labelling of nucleic acids. While a majority of literature reports mark cell-surface exposed targets, implementing bioorthogonal ligations in the interior of cells constitutes a more challenging task. Owing to limiting factors such as membrane permeability of reagents, fluorescence background due to hydrophobic interactions and off-target covalent binding, and suboptimal balance between reactivity and stability of the designed molecular reporters and probes, these strategies need mindful planning to achieve success. In this review, we discuss the hurdles encountered when targeting biomolecules localized in cell organelles and give an easily accessible summary of the strategies at hand for imaging intracellular targets.
Collapse
Affiliation(s)
- Vincent Rigolot
- UMR 8576 CNRS, Unité de Glycobiologie Structurale et Fonctionnelle, Université de Lille, Faculté des Sciences et Technologies, Bât. C9, 59655, Villeneuve d'Ascq, France
| | - Christophe Biot
- UMR 8576 CNRS, Unité de Glycobiologie Structurale et Fonctionnelle, Université de Lille, Faculté des Sciences et Technologies, Bât. C9, 59655, Villeneuve d'Ascq, France
| | - Cedric Lion
- UMR 8576 CNRS, Unité de Glycobiologie Structurale et Fonctionnelle, Université de Lille, Faculté des Sciences et Technologies, Bât. C9, 59655, Villeneuve d'Ascq, France
| |
Collapse
|
21
|
Jalali E, Thorson JS. Enzyme-mediated bioorthogonal technologies: catalysts, chemoselective reactions and recent methyltransferase applications. Curr Opin Biotechnol 2021; 69:290-298. [PMID: 33901763 DOI: 10.1016/j.copbio.2021.02.010] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2021] [Revised: 02/24/2021] [Accepted: 02/26/2021] [Indexed: 12/28/2022]
Abstract
Transferases have emerged as among the best catalysts for enzyme-mediated bioorthogonal functional group installation to advance innovative in vitro, cell-based and in vivo chemical biology applications. This review introduces the key considerations for selecting enzyme catalysts and chemoselective reactions most amenable to bioorthogonal platform development and highlights relevant key technology development and applications for one ubiquitous transferase subclass - methyltransferases (MTs). Within this context, recent advances in MT-enabled bioorthogonal labeling/conjugation relevant to DNA, RNA, protein, and natural products (i.e. complex small molecule metabolites) are highlighted.
Collapse
Affiliation(s)
- Elnaz Jalali
- Department of Pharmaceutical Sciences, University of Kentucky College of Pharmacy, Lexington, KY 40536, United States
| | - Jon S Thorson
- Department of Pharmaceutical Sciences, University of Kentucky College of Pharmacy, Lexington, KY 40536, United States; Center for Pharmaceutical Research and Innovation, University of Kentucky College of Pharmacy, Lexington, KY 40536, United States.
| |
Collapse
|
22
|
Ando T, Takamori Y, Yokoyama T, Yamamoto M, Kawakami T. Directed evolution of dibenzocyclooctyne-reactive peptide tags for protein labeling. Biochem Biophys Res Commun 2020; 534:27-33. [PMID: 33310184 DOI: 10.1016/j.bbrc.2020.12.002] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2020] [Accepted: 12/03/2020] [Indexed: 01/02/2023]
Abstract
Protein labeling with a functional molecule is a technique widely used for protein research. The covalent reaction of self-labeling peptide tags with synthetic probe-modified small molecules enables tag-fused protein labeling with chemically diverse molecules, including fluorescent probes. We report the discovery, by in vitro directed evolution, of a novel 23-mer dibenzocyclooctyne (DBCO)-reactive peptide (DRP) tag using Systematic Evolution of Ligands by EXponential enrichment (SELEX) with a combination of a reconstituted cell-free translation system (PURE system) and cDNA display. The N- and C-terminal DRP truncations created a shorter 16-mer DBCO-reactive peptide (sDRP) tag without significant reactivity reduction. By fusing the sDRP tag to a model protein, we showed the chemical labeling and in-gel fluorescence imaging of the sDRP-fused protein using a fluorescent DBCO probe. Results showed that sDRP tag-mediated protein labeling has potential for use as a basic molecular tool in a variety of applications for protein research.
Collapse
Affiliation(s)
- Takehiro Ando
- Department of Life and Environmental Sciences, Integrated Graduate School of Medicine, Engineering, and Agricultural Sciences, University of Yamanashi, 4-4-37 Takeda, Kofu, Yamanashi, 400-8510, Japan
| | - Yukio Takamori
- Department of Life and Environmental Sciences, Integrated Graduate School of Medicine, Engineering, and Agricultural Sciences, University of Yamanashi, 4-4-37 Takeda, Kofu, Yamanashi, 400-8510, Japan
| | - Takumi Yokoyama
- Department of Life and Environmental Sciences, Integrated Graduate School of Medicine, Engineering, and Agricultural Sciences, University of Yamanashi, 4-4-37 Takeda, Kofu, Yamanashi, 400-8510, Japan
| | - Mizuki Yamamoto
- Department of Integrated Applied Life Science, Integrated Graduate School of Medicine, Engineering, and Agricultural Sciences, University of Yamanashi, 4-4-37 Takeda, Kofu, Yamanashi, 400-8510, Japan
| | - Takashi Kawakami
- Faculty of Life and Environmental Sciences, Graduate Faculty of Interdisciplinary Research, University of Yamanashi, 4-4-37 Takeda, Kofu, Yamanashi, 400-8510, Japan; JST, PRESTO, 4-1-8 Honcho, Kawaguchi, Saitama, 332-0012, Japan.
| |
Collapse
|
23
|
Macias‐Contreras M, Zhu L. The Collective Power of Genetically Encoded Protein/Peptide Tags and Bioorthogonal Chemistry in Biological Fluorescence Imaging. CHEMPHOTOCHEM 2020. [DOI: 10.1002/cptc.202000215] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Affiliation(s)
- Miguel Macias‐Contreras
- Department of Chemistry and Biochemistry Florida State University 95 Chieftan Way Tallahassee FL 32306-4390 USA
| | - Lei Zhu
- Department of Chemistry and Biochemistry Florida State University 95 Chieftan Way Tallahassee FL 32306-4390 USA
| |
Collapse
|
24
|
Macias-Contreras M, Little KN, Zhu L. Expanding the substrate selectivity of SNAP/CLIP-tagging of intracellular targets. Methods Enzymol 2020; 638:233-257. [PMID: 32416915 DOI: 10.1016/bs.mie.2020.02.021] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/30/2023]
Abstract
SNAP-tag belongs to a class of genetic tools of protein labeling that complements fluorescent proteins. This single-turnover enzyme is a mutant of human DNA repair protein O6-alkylguanine-DNA alkyltransferase (hAGT). It accepts, in most cases, label-carrying O6-benzylguanines or benzyl-2-chloro-6-aminopyrimidines as suitable substrates. In this article, strategies and methods to expand the scope of the labels for intracellular proteins of live cells via the actions of SNAP-tag are presented. CLIP-tag is another mutant of the hAGT that was engineered to have mutually exclusive substrate specificity from SNAP-tag. The use of complementary bioorthogonal chemical reactions in conjunction with orthogonal enzymatic SNAP/CLIP-tags for the purpose of dual-color intracellular labeling is also described.
Collapse
Affiliation(s)
- Miguel Macias-Contreras
- Department of Chemistry and Biochemistry, Florida State University, Tallahassee, FL, United States
| | - Kevin N Little
- Department of Chemistry and Biochemistry, Florida State University, Tallahassee, FL, United States
| | - Lei Zhu
- Department of Chemistry and Biochemistry, Florida State University, Tallahassee, FL, United States.
| |
Collapse
|