1
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Grain B, Desmet R, Snella B, Melnyk O, Agouridas V. Incorporation of a Highly Reactive Oxalyl Thioester-Based Interacting Handle into Proteins. Org Lett 2023; 25:5117-5122. [PMID: 37384828 PMCID: PMC10353032 DOI: 10.1021/acs.orglett.3c01846] [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: 06/06/2023] [Indexed: 07/01/2023]
Abstract
Providing biomolecules with extended physicochemical, biochemical, or biological properties is a contemporary challenge motivated by impactful benefits in life or materials sciences. In this study, we show that a latent and highly reactive oxalyl thioester precursor can be efficiently introduced as a pending functionality into a fully synthetic protein domain following a protection/late-stage deprotection strategy and can serve as an on-demand reactive handle. The approach is illustrated with the production of a 10 kDa ubiquitin Lys48 conjugate.
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Affiliation(s)
- Benjamin Grain
- Univ.
Lille, CNRS, Inserm, CHU Lille, Institut Pasteur de Lille, U1019 -
UMR 9017 - CIIL - Center for Infection and Immunity of Lille, F-59000 Lille, France
| | - Rémi Desmet
- Univ.
Lille, CNRS, Inserm, CHU Lille, Institut Pasteur de Lille, U1019 -
UMR 9017 - CIIL - Center for Infection and Immunity of Lille, F-59000 Lille, France
| | - Benoît Snella
- Univ.
Lille, CNRS, Inserm, CHU Lille, Institut Pasteur de Lille, U1019 -
UMR 9017 - CIIL - Center for Infection and Immunity of Lille, F-59000 Lille, France
| | - Oleg Melnyk
- Univ.
Lille, CNRS, Inserm, CHU Lille, Institut Pasteur de Lille, U1019 -
UMR 9017 - CIIL - Center for Infection and Immunity of Lille, F-59000 Lille, France
| | - Vangelis Agouridas
- Univ.
Lille, CNRS, Inserm, CHU Lille, Institut Pasteur de Lille, U1019 -
UMR 9017 - CIIL - Center for Infection and Immunity of Lille, F-59000 Lille, France
- Centrale
Lille, F-59000 Lille, France
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2
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Wang Y, Song C, Xing Y, Shen S, Bo T, Zhang N, Wang J, Shi T, Huo S. l-Methionine Selenoxide as an Oxidizing and Deprotection Reagent for the Synthesis of Multiple Disulfide Bonds in Peptides. J Org Chem 2023; 88:8123-8132. [PMID: 37235643 DOI: 10.1021/acs.joc.3c00104] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
The regioselective synthesis of multiple disulfide bonds in peptides has been a significant challenge in synthetic peptide chemistry. In this work, two disulfide bonds in peptides were regioselectively synthesized via an approach of MetSeO oxidation and deprotection reaction (SeODR), in which the first disulfide bond was constructed through oxidation of dithiol by MetSeO in a neutral buffer, and the second disulfide bond was then directly constructed through the deprotection of two Acm groups or one Acm group and one Thz group by MetSeO in acidic media. Synthesis of two disulfide bonds by the SeODR approach was achieved through a one-pot manner. Moreover, the SeODR approach is compatible with the synthesis of peptides containing methionine residues. Both H+ and Br- drastically promoted the reaction rate of SeODR. The mechanistic picture for the SeODR approach was delineated, in which the formation of a stable Se-X-S bridge as the transition state plays a critical role. The SeODR approach was also utilized to construct the three disulfide bonds in linaclotide, conferring a reasonable yield.
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Affiliation(s)
- Yafang Wang
- College of Chemistry and Materials Science, Key Laboratory of Analytical Science and Technology of Hebei Province, and MOE Key Laboratory of Medicinal Chemistry and Molecular Diagnostics, Hebei University, Baoding 071002, Hebei Province, China
| | - Changying Song
- College of Chemistry and Materials Science, Key Laboratory of Analytical Science and Technology of Hebei Province, and MOE Key Laboratory of Medicinal Chemistry and Molecular Diagnostics, Hebei University, Baoding 071002, Hebei Province, China
| | - Yueyue Xing
- College of Chemistry and Materials Science, Key Laboratory of Analytical Science and Technology of Hebei Province, and MOE Key Laboratory of Medicinal Chemistry and Molecular Diagnostics, Hebei University, Baoding 071002, Hebei Province, China
| | - Shigang Shen
- College of Chemistry and Materials Science, Key Laboratory of Analytical Science and Technology of Hebei Province, and MOE Key Laboratory of Medicinal Chemistry and Molecular Diagnostics, Hebei University, Baoding 071002, Hebei Province, China
| | - Tianyu Bo
- College of Chemistry and Materials Science, Key Laboratory of Analytical Science and Technology of Hebei Province, and MOE Key Laboratory of Medicinal Chemistry and Molecular Diagnostics, Hebei University, Baoding 071002, Hebei Province, China
| | - Nan Zhang
- College of Chemistry and Materials Science, Key Laboratory of Analytical Science and Technology of Hebei Province, and MOE Key Laboratory of Medicinal Chemistry and Molecular Diagnostics, Hebei University, Baoding 071002, Hebei Province, China
| | - Jixu Wang
- College of Chemistry and Materials Science, Key Laboratory of Analytical Science and Technology of Hebei Province, and MOE Key Laboratory of Medicinal Chemistry and Molecular Diagnostics, Hebei University, Baoding 071002, Hebei Province, China
| | - Tiesheng Shi
- College of Chemistry, Chemical Engineering and Materials Science, Zaozhuang University, Zaozhuang 277160, Shandong Province, China
| | - Shuying Huo
- College of Chemistry and Materials Science, Key Laboratory of Analytical Science and Technology of Hebei Province, and MOE Key Laboratory of Medicinal Chemistry and Molecular Diagnostics, Hebei University, Baoding 071002, Hebei Province, China
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3
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Xing Y, Wang Y, Ma D, Shen S, Song C, Zhang N, Bo T, Shi T, Huo S. N-Halosuccinimides mediated deprotection of cysteine-S protecting groups for one-pot regioselective synthesis of disulfide bonds in peptides under mild aqueous conditions. Tetrahedron Lett 2023. [DOI: 10.1016/j.tetlet.2023.154459] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/31/2023]
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4
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Vince MJK, Holub JM. Synthesis of Scyllatoxin-Based BH3 Domain Mimetics with Diverse Patterns of Native Disulfide Bonds. Curr Protoc 2022; 2:e526. [PMID: 35994574 DOI: 10.1002/cpz1.526] [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: 06/15/2023]
Abstract
This article outlines the design and development of scyllatoxin (ScTx)-based BH3 domain mimetics with diverse patterns of native disulfide bonds. More specifically, this method summarizes the total chemical synthesis of ScTx-based peptides that contain zero, one, two, or three disulfide linkages, including techniques to generate variants with any combination of native disulfides. Each peptide reported herein is generated on solid-phase support using microwave-assisted coupling procedures, and all reaction parameters related to the peptide synthesis are described in detail. The various disulfide patterns of the ScTx-based constructs are established during peptide synthesis and are ultimately verified by mass analysis of trypsin-digested fragments. The BH3 domain mimetics developed herein were generated by transposing residues from the helical BH3 domain of the pro-apoptotic BCL2 protein Bax to the α-helix of wild-type ScTx. Interestingly, we found that the relative binding affinities of ScTx-Bax peptides for the anti-apoptotic BCL2 protein Bcl-2 (proper) were heavily influenced by the number and position of disulfide linkages within the ScTx-Bax sequence. As a consequence, we were able to utilize ScTx-Bax BH3 domain mimetics with varied patterns of disulfide bonds to survey how structural rigidity within the helical Bax BH3 domain affects binding to promiscuous anti-apoptotic BCL2 proteins. More broadly, the ability to generate ScTx-based molecules that contain any combination of native disulfide bonds expands the utility of such constructs as tools to study the molecular nature of protein-protein interactions. © 2022 Wiley Periodicals LLC. Basic Protocol 1: Synthesis and characterization of ScTx-based Bax BH3 domain mimetics Basic Protocol 2: Oxidation of ScTx-Bax BH3 domain mimetics containing one, two, or three disulfide linkages Support Protocol: Mapping of disulfide linkages in oxidized ScTx-Bax BH3 domain mimetics.
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Affiliation(s)
- Matthew J K Vince
- Department of Chemistry and Biochemistry, Ohio University, Athens, Ohio
- Institut für Bioanalytische Chemie, Fakultät für Chemie und Mineralogie, Universität Leipzig, Leipzig, Germany
- Biotechnologisch-Biomedizinisches Zentrum, Universität Leipzig, Leipzig, Germany
| | - Justin M Holub
- Department of Chemistry and Biochemistry, Ohio University, Athens, Ohio
- Edison Biotechnology Institute, Ohio University, Athens, Ohio
- Molecular and Cellular Biology Program, Ohio University, Athens, Ohio
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5
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Kobayashi D, Kuraoka E, Hayashi J, Yasuda T, Kohmura Y, Denda M, Harada N, Inagaki N, Otaka A. S-Protected Cysteine Sulfoxide-Enabled Tryptophan-Selective Modification with Application to Peptide Lipidation. ACS Med Chem Lett 2022; 13:1125-1130. [DOI: 10.1021/acsmedchemlett.2c00161] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Affiliation(s)
- Daishiro Kobayashi
- Institute of Biomedical Sciences and Graduate School of Pharmaceutical Sciences, Tokushima University, Tokushima 770-8505, Japan
| | - Eisuke Kuraoka
- Institute of Biomedical Sciences and Graduate School of Pharmaceutical Sciences, Tokushima University, Tokushima 770-8505, Japan
| | - Junya Hayashi
- Institute of Biomedical Sciences and Graduate School of Pharmaceutical Sciences, Tokushima University, Tokushima 770-8505, Japan
| | - Takuma Yasuda
- Department of Diabetes, Endocrinology and Nutrition, Graduate School of Medicine, Kyoto University, Kyoto 606-8507, Japan
| | - Yutaka Kohmura
- Institute of Biomedical Sciences and Graduate School of Pharmaceutical Sciences, Tokushima University, Tokushima 770-8505, Japan
| | - Masaya Denda
- Institute of Biomedical Sciences and Graduate School of Pharmaceutical Sciences, Tokushima University, Tokushima 770-8505, Japan
| | - Norio Harada
- Department of Diabetes, Endocrinology and Nutrition, Graduate School of Medicine, Kyoto University, Kyoto 606-8507, Japan
| | - Nobuya Inagaki
- Department of Diabetes, Endocrinology and Nutrition, Graduate School of Medicine, Kyoto University, Kyoto 606-8507, Japan
| | - Akira Otaka
- Institute of Biomedical Sciences and Graduate School of Pharmaceutical Sciences, Tokushima University, Tokushima 770-8505, Japan
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6
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Jin M, Gläser A, Paez JI. Redox-triggerable firefly luciferin-bioinspired hydrogels as injectable and cell-encapsulating matrices. Polym Chem 2022. [DOI: 10.1039/d2py00481j] [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
A novel redox-triggered bioinspired hydrogel platform that offers high control over gelation onset and kinetics is presented. This platform is suitable for the development of injectable matrices.
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Affiliation(s)
- Minye Jin
- INM – Leibniz Institute for New Materials, Campus D2-2, 66123, Saarbrücken, Germany
- Chemistry Department, Saarland University, 66123, Saarbrücken, Germany
- Developmental Bioengineering, University of Twente, Drienerlolaan 5, 7522 NB, Enschede, The Netherlands
| | - Alisa Gläser
- INM – Leibniz Institute for New Materials, Campus D2-2, 66123, Saarbrücken, Germany
| | - Julieta I. Paez
- INM – Leibniz Institute for New Materials, Campus D2-2, 66123, Saarbrücken, Germany
- Developmental Bioengineering, University of Twente, Drienerlolaan 5, 7522 NB, Enschede, The Netherlands
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7
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Ste. Marie EJ, Hondal RJ. Application of alpha-methyl selenocysteine as a tool for the study of selenoproteins. Methods Enzymol 2022; 662:297-329. [DOI: 10.1016/bs.mie.2021.10.016] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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8
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Spears RJ, McMahon C, Chudasama V. Cysteine protecting groups: applications in peptide and protein science. Chem Soc Rev 2021; 50:11098-11155. [PMID: 34605832 DOI: 10.1039/d1cs00271f] [Citation(s) in RCA: 47] [Impact Index Per Article: 15.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Protecting group chemistry for the cysteine thiol group has enabled a vast array of peptide and protein chemistry over the last several decades. Increasingly sophisticated strategies for the protection, and subsequent deprotection, of cysteine have been developed, facilitating synthesis of complex disulfide-rich peptides, semisynthesis of proteins, and peptide/protein labelling in vitro and in vivo. In this review, we analyse and discuss the 60+ individual protecting groups reported for cysteine, highlighting their applications in peptide synthesis and protein science.
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Affiliation(s)
| | - Clíona McMahon
- Department of Chemistry, University College London, London, UK.
| | - Vijay Chudasama
- Department of Chemistry, University College London, London, UK.
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9
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Küppers J, Benkel T, Annala S, Kimura K, Reinelt L, Fleischmann BK, Kostenis E, Gütschow M. Tetrahydroimidazo[1,2-a]pyrazine Derivatives: Synthesis and Evaluation as Gα q -Protein Ligands. Chemistry 2020; 26:12615-12623. [PMID: 32428383 PMCID: PMC7590114 DOI: 10.1002/chem.202001446] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2020] [Revised: 05/06/2020] [Indexed: 12/14/2022]
Abstract
The 5,6,7,8-tetrahydroimidazo[1,2-a]pyrazine derivative BIM-46174 and its dimeric form BIM-46187 (1) are heterocyclized dipeptides that belong to the very few cell-permeable compounds known to preferentially silence Gαq proteins. To explore the chemical space of Gαq inhibitors of the BIM chemotype, a combinatorial approach was conducted towards a library of BIM molecules. This library was evaluated in a second messenger-based fluorescence assay to analyze the activity of Gαq proteins through the determination of intracellular myo-inositol 1-phosphate. Structure-activity relationships were deduced and structural requirements for biological activity obtained, which were (i) a redox reactive thiol/disulfane substructure, (ii) an N-terminal basic amino group, (iii) a cyclohexylalanine moiety, and (iv) a bicyclic skeleton. Active compounds exhibited cellular toxicity, which was investigated in detail for the prototypical inhibitor 1. This compound affects the structural cytoskeletal dynamics in a Gαq/11 -independent manner.
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Affiliation(s)
- Jim Küppers
- Pharmaceutical InstituteDepartment of Pharmaceutical & Medicinal ChemistryUniversity of BonnAn der Immenburg 453121BonnGermany
| | - Tobias Benkel
- Molecular, Cellular and Pharmacobiology SectionInstitute for Pharmaceutical BiologyUniversity of BonnNussallee 653115BonnGermany
- Research Training Group 1873University of Bonn53115BonnGermany
| | - Suvi Annala
- Molecular, Cellular and Pharmacobiology SectionInstitute for Pharmaceutical BiologyUniversity of BonnNussallee 653115BonnGermany
| | - Kenichi Kimura
- Institute of Physiology I, Life and Brain Center, Medical FacultyUniversity of BonnSigmund-Freud-Str. 2553105BonnGermany
| | - Lisa Reinelt
- Pharmaceutical InstituteDepartment of Pharmaceutical & Medicinal ChemistryUniversity of BonnAn der Immenburg 453121BonnGermany
| | - Bernd K. Fleischmann
- Institute of Physiology I, Life and Brain Center, Medical FacultyUniversity of BonnSigmund-Freud-Str. 2553105BonnGermany
| | - Evi Kostenis
- Molecular, Cellular and Pharmacobiology SectionInstitute for Pharmaceutical BiologyUniversity of BonnNussallee 653115BonnGermany
| | - Michael Gütschow
- Pharmaceutical InstituteDepartment of Pharmaceutical & Medicinal ChemistryUniversity of BonnAn der Immenburg 453121BonnGermany
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10
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He R, Pan J, Mayer JP, Liu F. Stepwise Construction of Disulfides in Peptides. Chembiochem 2020; 21:1101-1111. [PMID: 31886929 DOI: 10.1002/cbic.201900717] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2019] [Indexed: 12/12/2022]
Abstract
The disulfide bond plays an important role in biological systems. It defines global conformation, and ultimately the biological activity and stability of the peptide or protein. It is frequently present, singly or multiply, in biologically important peptide hormones and toxins. Numerous disulfide-containing peptides have been approved by the regulatory agencies as marketed drugs. Chemical synthesis is one of the prerequisite tools needed to gain deep insights into the structure-function relationships of these biomolecules. Along with the development of solid-phase peptide synthesis, a number of methods of disulfide construction have been established. This minireview will focus on the regiospecific, stepwise construction of multiple disulfides used in the chemical synthesis of peptides. We intend for this article to serve a reference for peptide chemists conducting complex peptide syntheses and also hope to stimulate the future development of disulfide methodologies.
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Affiliation(s)
- Rongjun He
- Novo Nordisk Research Center Indianapolis, 5225 Exploration Drive, Indianapolis, IN, 46241, USA
| | - Jia Pan
- Novo Nordisk Research Center China, 20 Life Science Road, Beijing, 102206, P. R. China
| | - John P Mayer
- Department of Molecular, Developmental & Cell Biology, University of Colorado, Boulder, CO, 80309, USA
| | - Fa Liu
- Novo Nordisk Research Center Seattle, 530 Fairview Avenue North, Seattle, WA, 98109, USA
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11
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Mueller LK, Baumruck AC, Zhdanova H, Tietze AA. Challenges and Perspectives in Chemical Synthesis of Highly Hydrophobic Peptides. Front Bioeng Biotechnol 2020; 8:162. [PMID: 32195241 PMCID: PMC7064641 DOI: 10.3389/fbioe.2020.00162] [Citation(s) in RCA: 48] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2019] [Accepted: 02/18/2020] [Indexed: 12/31/2022] Open
Abstract
Solid phase peptide synthesis (SPPS) provides the possibility to chemically synthesize peptides and proteins. Applying the method on hydrophilic structures is usually without major drawbacks but faces extreme complications when it comes to "difficult sequences." These includes the vitally important, ubiquitously present and structurally demanding membrane proteins and their functional parts, such as ion channels, G-protein receptors, and other pore-forming structures. Standard synthetic and ligation protocols are not enough for a successful synthesis of these challenging sequences. In this review we highlight, summarize and evaluate the possibilities for synthetic production of "difficult sequences" by SPPS, native chemical ligation (NCL) and follow-up protocols.
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Affiliation(s)
- Lena K. Mueller
- Clemens-Schöpf Institute of Organic Chemistry and Biochemistry, Darmstadt University of Technology, Darmstadt, Germany
| | - Andreas C. Baumruck
- Clemens-Schöpf Institute of Organic Chemistry and Biochemistry, Darmstadt University of Technology, Darmstadt, Germany
| | - Hanna Zhdanova
- Department of Chemistry and Molecular Biology, Wallenberg Centre for Molecular and Translational Medicine, University of Gothenburg, Gothenburg, Sweden
| | - Alesia A. Tietze
- Department of Chemistry and Molecular Biology, Wallenberg Centre for Molecular and Translational Medicine, University of Gothenburg, Gothenburg, Sweden
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12
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Ste.Marie EJ, Hondal RJ. 2,2'-Dipyridyl diselenide: A chemoselective tool for cysteine deprotection and disulfide bond formation. J Pept Sci 2020; 26:e3236. [PMID: 31856422 PMCID: PMC7509986 DOI: 10.1002/psc.3236] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2019] [Revised: 10/26/2019] [Accepted: 11/04/2019] [Indexed: 11/05/2022]
Abstract
There are many examples of bioactive, disulfide-rich peptides and proteins whose biological activity relies on proper disulfide connectivity. Regioselective disulfide bond formation is a strategy for the synthesis of these bioactive peptides, but many of these methods suffer from a lack of orthogonality between pairs of protected cysteine (Cys) residues, efficiency, and high yields. Here, we show the utilization of 2,2'-dipyridyl diselenide (PySeSePy) as a chemical tool for the removal of Cys-protecting groups and regioselective formation of disulfide bonds in peptides. We found that peptides containing either Cys(Mob) or Cys(Acm) groups treated with PySeSePy in trifluoroacetic acid (TFA) (with or without triisopropylsilane (TIS) were converted to Cys-S-SePy adducts at 37 °C and various incubation times. This novel Cys-S-SePy adduct is able to be chemoselectively reduced by five-fold excess ascorbate at pH 4.5, a condition that should spare already installed peptide disulfide bonds from reduction. This chemoselective reduction by ascorbate will undoubtedly find utility in numerous biotechnological applications. We applied our new chemistry to the iodine-free synthesis of the human intestinal hormone guanylin, which contains two disulfide bonds. While we originally envisioned using ascorbate to chemoselectively reduce one of the formed Cys-S-SePy adducts to catalyze disulfide bond formation, we found that when pairs of Cys(Acm) residues were treated with PySeSePy in TFA, the second disulfide bond formed spontaneously. Spontaneous formation of the second disulfide is most likely driven by the formation of the thermodynamically favored diselenide (PySeSePy) from the two Cys-S-SePy adducts. Thus, we have developed a one-pot method for concomitant deprotection and disulfide bond formation of Cys(Acm) pairs in the presence of an existing disulfide bond.
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Affiliation(s)
- Emma J. Ste.Marie
- Department of Chemistry, Discovery Hall, University of Vermont, 82 University Place, Burlington, VT 05405, USA
- ESM was supported by National Institutes of Health Training Grant T32 HL07594 administered by Dr. Kenneth G. Mann and Dr. Robert J. Kelm
| | - Robert J. Hondal
- Department of Chemistry, Discovery Hall, University of Vermont, 82 University Place, Burlington, VT 05405, USA
- University of Vermont, Department of Biochemistry, 89 Beaumont Ave, Given Laboratory, Room B413, Burlington, VT 05405, USA
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13
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Jenny KA, Ste. Marie EJ, Mose G, Ruggles EL, Hondal RJ. Facile removal of 4-methoxybenzyl protecting group from selenocysteine. J Pept Sci 2019; 25:e3209. [PMID: 31410953 PMCID: PMC6851407 DOI: 10.1002/psc.3209] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2019] [Revised: 07/20/2019] [Accepted: 07/22/2019] [Indexed: 12/22/2022]
Abstract
Historically, methods to remove the 4-methoxybenzyl (Mob)-protecting group from selenocysteine (Sec) in peptides have used harsh and toxic reagents. The use of 2,2'-dithiobis-5-nitropyridine (DTNP) is an improvement over these methods; however, many wash steps are required to remove the by-product contaminant 5-nitro-2-thiopyridine. Even with many washes, excess DTNP adheres to the peptide. The final product needs excess purification to remove these contaminants. It was recently discovered by our group that hindered hydrosilanes could be used to reduce Cys(Mob). We sought to apply a similar methodology to reduce Sec(Mob), which we expected to be even more labile. Here, we present a gentle and facile method for deprotection of Sec(Mob) using triethylsilane (TES), phenol, and a variety of other scavengers often used in deprotection cocktails. The different cocktails were all incubated at 40 °C for 4 hours. The combination of TFA/TES/thioanisole (96:2:2) appeared to be the most efficient of the cocktails tested, providing complete deprotection and yielded peptide that was mainly in the diselenide form. This cocktail also showed no evidence of side reactions or significant contaminants in the high-performance liquid chromatography (HPLC) and mass spectral (MS) analyses. We envision that our new method will allow for a simple and gentle "one-pot" deprotection of Sec(Mob) following solid-phase peptide synthesis and will minimize the need for extensive purification steps.
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Affiliation(s)
- Kaelyn A. Jenny
- Department of Chemistry, Discovery Hall, University of Vermont, 82 University Place, Burlington, VT 05405, USA
| | - Emma J. Ste. Marie
- Department of Chemistry, Discovery Hall, University of Vermont, 82 University Place, Burlington, VT 05405, USA
- University of Vermont, Department of Biochemistry, 89 Beaumont Ave, Given Laboratory, Room B413, Burlington, VT 05405, USA
| | - Gracyn Mose
- University of Vermont, Department of Biochemistry, 89 Beaumont Ave, Given Laboratory, Room B413, Burlington, VT 05405, USA
| | - Erik L. Ruggles
- Department of Chemistry, Discovery Hall, University of Vermont, 82 University Place, Burlington, VT 05405, USA
| | - Robert J. Hondal
- Department of Chemistry, Discovery Hall, University of Vermont, 82 University Place, Burlington, VT 05405, USA
- University of Vermont, Department of Biochemistry, 89 Beaumont Ave, Given Laboratory, Room B413, Burlington, VT 05405, USA
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