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Kalmer H, Sbordone F, Frisch H. Peptide based folding and function of single polymer chains. Polym Chem 2022. [DOI: 10.1039/d2py00717g] [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 modular synthetic strategy to fold single polymer chains upon deprotection of pendent cysteine terminal peptides is reported. The one step deprotection initiates both folding and catalytic activity of the macromolecular architectures.
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Affiliation(s)
- Henrik Kalmer
- Centre for Materials Science, Queensland University of Technology (QUT), 2 George Street, Brisbane, QLD 4000, Australia
- School of Chemistry and Physics, Queensland University of Technology (QUT), 2 George Street, Brisbane, QLD 4000, Australia
| | - Federica Sbordone
- Centre for Materials Science, Queensland University of Technology (QUT), 2 George Street, Brisbane, QLD 4000, Australia
- School of Chemistry and Physics, Queensland University of Technology (QUT), 2 George Street, Brisbane, QLD 4000, Australia
| | - Hendrik Frisch
- Centre for Materials Science, Queensland University of Technology (QUT), 2 George Street, Brisbane, QLD 4000, Australia
- School of Chemistry and Physics, Queensland University of Technology (QUT), 2 George Street, Brisbane, QLD 4000, Australia
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2
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Pawlas J, Svensson T, Rasmussen JH. 1,4-Benzenedimethanethiol (1,4-BDMT) as a scavenger for greener peptide resin cleavages. RSC Adv 2019; 9:38928-38934. [PMID: 35540669 PMCID: PMC9075962 DOI: 10.1039/c9ra08553j] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2019] [Accepted: 11/20/2019] [Indexed: 11/25/2022] Open
Abstract
Aiming at elevating the environmental profile of the solid-phase peptide synthesis (SPPS) methodology by improving the quality of crude peptides that SPPS provides we assessed a series of benzylthiols (BTs) as scavengers for global deprotection/TFA cleavage of exenatide peptide resin accessed by Fmoc SPPS. In these studies we identified 1,4-BDMT as a scavenger that affords the peptide in higher quality than the standard aliphatic thiol reagents, not least in terms of the content of critical peptide impurities in the crude material. Further, 1,4-BDMT exhibited favorable UV detectability as well as stability and solubility in TFA. Finally, based on the MS assessment of the crude exenatide products herein we propose that thiol scavengers in the cleavage of Trp containing peptide resins do not minimize the content of Trp oxidants by means of inhibiting Trp oxidation but rather by forming a peptide–thiol adduct via a mechanism involving an attack of a thiol on an oxindolylalanine (Oia) impurity present in the crude material. 1,4-BDMT is a benign, non-odorous scavenger for peptide resin cleavages which provides crude peptides in higher quality than the aliphatic thiols used for this purpose.![]()
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Ste Marie EJ, Hondal RJ. Reduction of cysteine-S-protecting groups by triisopropylsilane. J Pept Sci 2018; 24:e3130. [PMID: 30353614 DOI: 10.1002/psc.3130] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2018] [Revised: 08/28/2018] [Accepted: 09/07/2018] [Indexed: 12/18/2022]
Abstract
Triisopropylsilane (TIS), a hindered hydrosilane, has long been utilized as a cation scavenger for the removal of amino acid protecting groups during peptide synthesis. However, its ability to actively remove S-protecting groups by serving as a reductant has largely been mischaracterized by the peptide community. Here, we provide strong evidence that TIS can act as a reducing agent to facilitate the removal of acetamidomethyl (Acm), 4-methoxybenzyl (Mob), and tert-butyl (But ) protecting groups from cysteine (Cys) residues in the presence of trifluoroacetic acid (TFA) at 37 °C. The lability of the Cys protecting groups in TFA/TIS (98/2) in this study are in the order: Cys(Mob) > Cys(Acm) > Cys(But ), with Cys(Mob) being especially labile. Unexpectedly, we found that TIS promoted disulfide formation in addition to aiding in the removal of the protecting group. Our results raise the possibility of using TIS in orthogonal deprotection strategies of Cys-protecting groups following peptide synthesis as TIS can be viewed as a potential deprotection agent instead of merely a scavenger in deprotection cocktails based on our results. We also tested other common scavengers under these reaction conditions and found that thioanisole and triethylsilane were similarly effective as TIS in enhancing deprotection and catalyzing disulfide formation. Our findings reported herein show that careful consideration should be given to the type of scavenger used when it is desirable to preserve the Cys-protecting group. Additional consideration should be given to the concentration of scavenger, temperature of the reaction, and reaction time.
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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
| | - Robert J Hondal
- Department of Biochemistry, University of Vermont, 89 Beaumont Ave, Given Laboratory, Room B413, Burlington, VT, 05405, USA
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D’Hondt M, Bracke N, Taevernier L, Gevaert B, Verbeke F, Wynendaele E, De Spiegeleer B. Related impurities in peptide medicines. J Pharm Biomed Anal 2014; 101:2-30. [DOI: 10.1016/j.jpba.2014.06.012] [Citation(s) in RCA: 54] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2014] [Revised: 06/05/2014] [Accepted: 06/08/2014] [Indexed: 12/16/2022]
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Harris PWR, Brimble MA. Toward the total chemical synthesis of the cancer protein NY-ESO-1. Biopolymers 2010; 94:542-50. [PMID: 20593475 DOI: 10.1002/bip.21351] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
During the course of developing a synthetic route for the cancer protein NY-ESO-1 using native chemical ligation, a number of the required thioester polypeptide fragments were unable to be synthesized effectively using Boc solid phase peptide synthesis. Modification of the SPPS protocols to include an arginine tag at the C terminus linked via the thioester resulted in a better purity profile and enhanced solubility, facilitating purification by HPLC. During preparation of another reactive partner for ligation that contained an internal Cys(Acm) residue by Fmoc SPPS, extensive loss of the Acm group occurred during cleavage from the resin while substitution with Cys(tBu) resulted in no loss of protecting group. It was shown that native chemical ligation of N-terminal cysteine peptide 155-180 containing the Cys(tBu) residue with thioester 140-154 was slow, incomplete and led to extensive HPLC column fouling. Subsequent incorporation of a C-terminal arginine tag into the N-terminal NY-ESO-1 155-180 fragment joined by a base labile 4-hydroxymethylbenzoic acid (HMBA) linker facilitated rapid quantitative ligation. The HMBA linker was demonstrated to be stable to the conditions required for native chemical ligation, subsequent transformations and final purification. Importantly it was effectively removed at pH=10.
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Affiliation(s)
- Paul W R Harris
- Department of Chemistry, University of Auckland, 23 Symonds St., Auckland 1142, New Zealand
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Muttenthaler M, Ramos YG, Feytens D, de Araujo AD, Alewood PF. p-Nitrobenzyl protection for cysteine and selenocysteine: a more stable alternative to the acetamidomethyl group. Biopolymers 2010; 94:423-32. [PMID: 20593464 DOI: 10.1002/bip.21502] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
This study evaluated the acidic lability of the acetamidomethyl (Acm), trimethylacetamidomethyl (Tacm), and the p-nitrobenzyl (pNB) as protecting groups for cysteine and selenocysteine (Sec) during the tert-butyloxycarbonyl (Boc)-chemistry solid-phase peptide synthesis of oxytocin (OT). Two novel Sec building blocks (Nalpha-tert-butyloxycarbonyl-Se(acetamidomethyl)-L-selenocysteine (Boc-L-Sec(Acm)-OH) and Nalpha-tert-butyloxycarbonyl-S(4-nitrobenzyl)-L-selenocysteine (Boc-L-Sec(pNB)-OH)) were developed for this study. Six partially protected thio- and seleno-OT analogues were synthesized, purified, and exposed to neat trifluoroacetic acid (TFA) at temperatures of 25, 40, 50, and 60 degrees C for 1 h, and HF treatment at 0 degrees C for 1 h. Significant losses were observed for the Acm and Tacm group in TFA at temperatures greater than 25 degrees C and during HF treatment at 0 degrees C, whereas the pNB group remained intact. Removal of the pNB was achieved via reduction to the p-aminobenzyl group either with zinc in acetic acid in solution or via tin chloride in hydrochloric acid on solid support, followed by oxidative cleavage with iodine yielding the corresponding disulfide or diselenide bond. No major side reactions were observed. This study confirms the occasionally described Acm instability and underpins the development of the pNB group as an alternative for cysteine and Sec protection.
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Affiliation(s)
- Markus Muttenthaler
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, QLD 4072, Australia
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Krishnamurthy VR, Dougherty A, Kamath M, Song X, Cummings RD, Chaikof EL. Synthesis of an Fmoc-threonine bearing core-2 glycan: a building block for PSGL-1 via Fmoc-assisted solid-phase peptide synthesis. Carbohydr Res 2010; 345:1541-7. [PMID: 20561607 PMCID: PMC2902660 DOI: 10.1016/j.carres.2010.05.004] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2010] [Revised: 05/02/2010] [Accepted: 05/06/2010] [Indexed: 01/13/2023]
Abstract
Selectins (L, E, and P) are vascular endothelial molecules that play an important role in the recruitment of leukocytes to inflamed tissue. In this regard, P-Selectin glycoprotein-1 (PSGL-1) has been identified as a ligand for P-Selectin. PSGL-1 binds to P-Selectin through the interaction of core-2 O-glycan expressing sialyl Lewis(x) oligosaccharide and the three tyrosine sulfate residues. Herein, we report the synthesis of threonine-linked core-2 O-glycan as an amino acid building block for the synthesis of PSGL-1. This building block was further incorporated in the Fmoc-assisted solid-phase peptide synthesis to provide a portion of the PSGL-1 glycopeptide.
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Affiliation(s)
- Venkata R Krishnamurthy
- Department of Biomedical Engineering, Emory University/Georgia Institute of Technology, and Department of Surgery, Emory University, Atlanta, GA 30322, USA
| | - Ann Dougherty
- Department of Biomedical Engineering, Emory University/Georgia Institute of Technology, and Department of Surgery, Emory University, Atlanta, GA 30322, USA
| | - Medha Kamath
- Department of Biomedical Engineering, Emory University/Georgia Institute of Technology, and Department of Surgery, Emory University, Atlanta, GA 30322, USA
| | - Xuezheng Song
- Department of Biochemistry, Emory University, Atlanta, GA 30322, USA
| | | | - Elliot. L. Chaikof
- Department of Biomedical Engineering, Emory University/Georgia Institute of Technology, and Department of Surgery, Emory University, Atlanta, GA 30322, USA
- School of Chemical and Biomolecular Engineering, Georgia Institute of Technology, Atlanta, GA 30332, USA
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Affiliation(s)
- Albert Isidro-Llobet
- Institute for Research in Biomedicine, Barcelona Science Park, Baldiri Reixac 10, 08028 Barcelona, Spain
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Abstract
While a number of methods exist for the production of N-methyl amino acid derivatives, the methods for the production of N-methyl cysteine (MeCys) derivatives are suboptimal as they either have low yields or lead to significant sulfhydryl deprotection during the synthetic protocol. This article focuses on the generation of MeCys and its subsequent use in Fmoc solid-phase peptide synthesis for the generation of N-methyl cystine containing peptides. Various methods for amino methylation of cysteine, in the presence of acid labile or acid stable sulfhydryl protecting groups, are compared and contrasted. Production of MeCys is best attained through formation of an oxazolidinone precursor obtained via cyclization of Fmoc--Cys(StBu)--OH. Following oxazolidinone ring opening, iminium ion reduction generates Fmoc--MeCys(StBu)--OH with an overall yield of 91%. The key to this procedure is using an electronically neutral Cys-derivative, as other polar Cys-derivatives gave poor results using the oxazolidinone procedure. Subsequently, the Fmoc--MeCys(StBu)--OH building block was used to replace a Cys residue with a MeCys residue in two peptide fragments that correspond to the active sites of glutaredoxin and thioredoxin reductase. The examples used here highlight the use of a MeCys(StBu) derivative, which allows for facile on-resin conversion to a MeCys(5-Npys) residue that can be subsequently used for intramolecular disulfide bond formation with concomitant cleavage of the peptide from the solid support. (c) 2007 Wiley Periodicals, Inc. Biopolymers (Pept Sci) 90: 61-68, 2008. This article was originally published online as an accepted preprint. The "Published Online" date corresponds to the preprint version. You can request a copy of the preprint by emailing the Biopolymers editorial office at biopolymers@wiley.com.
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Affiliation(s)
- Erik L Ruggles
- Department of Biochemistry, 89 Beaumont Ave, Given Laboratory, Room B413, Burlington, VT 05405
| | - Stevenson Flemer
- Department of Biochemistry, 89 Beaumont Ave, Given Laboratory, Room B413, Burlington, VT 05405
| | - Robert J. Hondal
- Department of Biochemistry, 89 Beaumont Ave, Given Laboratory, Room B413, Burlington, VT 05405
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Marcucci E, Bayó-Puxan N, Tulla-Puche J, Spengler J, Albericio F. Cysteine-S-trityl a Key Derivative to PrepareN-Methyl Cysteines. ACTA ACUST UNITED AC 2008; 10:69-78. [DOI: 10.1021/cc7001588] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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