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Fukumoto K, Yazaki M, Arisawa M. Synthesis of Unprotected Cyclic Peptide Methylene Dithioacetals by Rhodium-Catalyzed Oxidation of Methanol to Formaldehyde. Org Lett 2024; 26:221-224. [PMID: 38134135 DOI: 10.1021/acs.orglett.3c03872] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2023]
Abstract
In the presence of a rhodium catalyst, unprotected peptide dithiols possessing two cysteine residues are efficiently converted to their corresponding cyclic methylene dithioacetals in a mixed solvent of methanol and water (4:1) under an oxygen atmosphere (1 atm). The slow formation of formaldehyde inhibits side reactions by maintaining its concentration at a low level, which is a key feature of this reaction. This method can be applied to peptide dithiols containing amino acids such as Gly, Ala, Ser, Lys, Met, Phe, Tyr, and His and provides cyclic methylene dithioacetals without being affected by other functional groups. Primary alcohols, such as ethanol and isopropanol, can also be employed. Oxytocin can be cyclized to provide a cyclic methylene dithioacetal.
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Affiliation(s)
- Kohei Fukumoto
- Department of Bioscience and Biotechnology, Graduate School of Bioresource and Bioenvironmental Sciences, Kyushu University, Fukuoka, 819-0395, Japan
- Department of Organic Chemistry, Graduate School of Pharmaceutical Sciences, Tohoku University, Aoba, Sendai, 980-8578, Japan
| | - Masana Yazaki
- Department of Bioscience and Biotechnology, Graduate School of Bioresource and Bioenvironmental Sciences, Kyushu University, Fukuoka, 819-0395, Japan
| | - Mieko Arisawa
- Department of Bioscience and Biotechnology, Graduate School of Bioresource and Bioenvironmental Sciences, Kyushu University, Fukuoka, 819-0395, Japan
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2
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Wharton L, McNeil SW, Merkens H, Yuan Z, Van de Voorde M, Engudar G, Ingham A, Koniar H, Rodríguez-Rodríguez C, Radchenko V, Ooms M, Kunz P, Bénard F, Schaffer P, Yang H. Preclinical Evaluation of [155/161Tb]Tb-Crown-TATE—A Novel SPECT Imaging Theranostic Agent Targeting Neuroendocrine Tumours. Molecules 2023; 28:molecules28073155. [PMID: 37049918 PMCID: PMC10095901 DOI: 10.3390/molecules28073155] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2023] [Revised: 03/24/2023] [Accepted: 03/27/2023] [Indexed: 04/05/2023] Open
Abstract
Terbium radioisotopes (149Tb, 152Tb, 155Tb, 161Tb) offer a unique class of radionuclides which encompass all four medicinally relevant nuclear decay modalities (α, β+, γ, β−/e−), and show high potential for the development of element-matched theranostic radiopharmaceuticals. The goal of this study was to design, synthesise, and evaluate the suitability of crown-TATE as a new peptide-conjugate for radiolabelling of [155Tb]Tb3+ and [161Tb]Tb3+, and to assess the imaging and pharmacokinetic properties of each radiotracer in tumour-bearing mice. [155Tb]Tb-crown-TATE and [161Tb]Tb-crown-TATE were prepared efficiently under mild conditions, and exhibited excellent stability in human serum (>99.5% RCP over 7 days). Longitudinal SPECT/CT images were acquired for 155Tb- and 161Tb- labelled crown-TATE in male NRG mice bearing AR42J tumours. The radiotracers, [155Tb]Tb-crown-TATE and [161Tb]Tb-crown-TATE, showed high tumour targeting (32.6 and 30.0 %ID/g, respectively) and minimal retention in non-target organs at 2.5 h post-administration. Biodistribution studies confirmed the SPECT/CT results, showing high tumour uptake (38.7 ± 8.0 %ID/g and 38.5 ± 3.5 %ID/g, respectively) and favourable tumour-to-background ratios. Blocking studies further confirmed SSTR2-specific tumour accumulation. Overall, these findings suggest that crown-TATE has great potential for element-matched molecular imaging and radionuclide therapy using 155Tb and 161Tb.
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Affiliation(s)
- Luke Wharton
- Life Sciences Division, TRIUMF, 4004 Wesbrook Mall, Vancouver, BC V6T 2A3, Canada
| | - Scott W. McNeil
- Life Sciences Division, TRIUMF, 4004 Wesbrook Mall, Vancouver, BC V6T 2A3, Canada
| | - Helen Merkens
- Department of Molecular Oncology, BC Cancer Research Institute, Vancouver, BC V5Z 1L3, Canada
| | - Zheliang Yuan
- Life Sciences Division, TRIUMF, 4004 Wesbrook Mall, Vancouver, BC V6T 2A3, Canada
| | - Michiel Van de Voorde
- Nuclear Medicine Applications, Belgium Nuclear Research Center (SCK CEN), Boeretang, 200, 2400 Mol, Belgium
| | - Gokce Engudar
- Life Sciences Division, TRIUMF, 4004 Wesbrook Mall, Vancouver, BC V6T 2A3, Canada
| | - Aidan Ingham
- Life Sciences Division, TRIUMF, 4004 Wesbrook Mall, Vancouver, BC V6T 2A3, Canada
| | - Helena Koniar
- Life Sciences Division, TRIUMF, 4004 Wesbrook Mall, Vancouver, BC V6T 2A3, Canada
- Department of Physics and Astronomy, University of British Columbia, 6224 Agronomy Road, Vancouver, BC V6T 1Z1, Canada
| | - Cristina Rodríguez-Rodríguez
- Department of Physics and Astronomy, University of British Columbia, 6224 Agronomy Road, Vancouver, BC V6T 1Z1, Canada
- Faculty of Pharmaceutical Sciences, University of British Columbia, 2405 Wesbrook Mall, Vancouver, BC V6T 1Z3, Canada
| | - Valery Radchenko
- Life Sciences Division, TRIUMF, 4004 Wesbrook Mall, Vancouver, BC V6T 2A3, Canada
- Department of Chemistry, University of British Columbia, 2036 Main Mall, Vancouver, BC V6T 1Z1, Canada
| | - Maarten Ooms
- Nuclear Medicine Applications, Belgium Nuclear Research Center (SCK CEN), Boeretang, 200, 2400 Mol, Belgium
| | - Peter Kunz
- Accelerator Division, TRIUMF, 4004 Wesbrook Mall, Vancouver, BC V6T 2A3, Canada
- Department of Chemistry, Simon Fraser University, Burnaby, BC V5A 1S6, Canada
| | - François Bénard
- Department of Molecular Oncology, BC Cancer Research Institute, Vancouver, BC V5Z 1L3, Canada
- Department of Radiology, University of British Columbia, Vancouver, BC V5Z 1M9, Canada
| | - Paul Schaffer
- Life Sciences Division, TRIUMF, 4004 Wesbrook Mall, Vancouver, BC V6T 2A3, Canada
- Department of Chemistry, Simon Fraser University, Burnaby, BC V5A 1S6, Canada
- Department of Radiology, University of British Columbia, Vancouver, BC V5Z 1M9, Canada
| | - Hua Yang
- Life Sciences Division, TRIUMF, 4004 Wesbrook Mall, Vancouver, BC V6T 2A3, Canada
- Department of Chemistry, Simon Fraser University, Burnaby, BC V5A 1S6, Canada
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3
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Lin J, Wang S, Wen L, Ye H, Shang S, Li J, Shu J, Zhou P. Targeting peptide-mediated interactions in omics. Proteomics 2023; 23:e2200175. [PMID: 36461811 DOI: 10.1002/pmic.202200175] [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: 10/07/2022] [Revised: 11/28/2022] [Accepted: 11/28/2022] [Indexed: 12/05/2022]
Abstract
Peptide-mediated interactions (PMIs) play a crucial role in cell signaling network, which are responsible for about half of cellular protein-protein associations in the human interactome and have recently been recognized as a new kind of promising druggable target for drug development and disease therapy. In this article, we give a systematic review regarding the proteome-wide discovery of PMIs and targeting druggable PMIs (dPMIs) with chemical drugs, self-inhibitory peptides (SIPs) and protein agents, particularly focusing on their implications and applications for therapeutic purpose in omics. We also introduce computational peptidology strategies used to model, analyze, and design PMI-targeted molecular entities and further extend the concepts of protein context, direct/indirect readout, and enthalpy/entropy effect involved in PMIs. Current issues and future perspective on this topic are discussed. There is still a long way to go before establishment of efficient therapeutic strategies to target PMIs on the omics scale.
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Affiliation(s)
- Jing Lin
- Center for Informational Biology, School of Life Science and Technology, University of Electronic Science and Technology of China (UESTC), Chengdu, China
| | - Shaozhou Wang
- Center for Informational Biology, School of Life Science and Technology, University of Electronic Science and Technology of China (UESTC), Chengdu, China
| | - Li Wen
- Center for Informational Biology, School of Life Science and Technology, University of Electronic Science and Technology of China (UESTC), Chengdu, China
| | - Haiyang Ye
- Center for Informational Biology, School of Life Science and Technology, University of Electronic Science and Technology of China (UESTC), Chengdu, China
| | - Shuyong Shang
- Institute of Ecological Environment Protection, Chengdu Normal University, Chengdu, China
| | - Juelin Li
- Center for Informational Biology, School of Life Science and Technology, University of Electronic Science and Technology of China (UESTC), Chengdu, China
| | - Jianping Shu
- Center for Informational Biology, School of Life Science and Technology, University of Electronic Science and Technology of China (UESTC), Chengdu, China
| | - Peng Zhou
- Center for Informational Biology, School of Life Science and Technology, University of Electronic Science and Technology of China (UESTC), Chengdu, China
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4
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Preparative Solid-Phase Method of S–S Bond Closure in Desamino-Analogs of Neurohypophyseal Hormones. Pharm Chem J 2022. [DOI: 10.1007/s11094-022-02787-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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5
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Nandhini KP, Albericio F, de la Torre BG. 2-Methoxy-4-methylsulfinylbenzyl Alcohol as a Safety-Catch Linker for the Fmoc/ tBu Solid-Phase Peptide Synthesis Strategy. J Org Chem 2022; 87:9433-9442. [PMID: 35801570 DOI: 10.1021/acs.joc.2c01057] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Fmoc and Boc group are the two main groups used to protect the α-amino function in Solid-Phase Peptide Synthesis (SPPS). In this regard, the use of the Mmsb linker allows the combination of these two groups. Peptide-O-Mmsb-Resin is stable to the piperidine and trifluoroacetic acid (TFA) treatment used to remove Fmoc and Boc, respectively. The peptide is detached in a two-step protocol, namely reduction of the sulfoxide to the sulfide with Me3SiCl and Ph3P, and then treatment with TFA. The advantage of this strategy has been demonstrated by the following: preparation of peptide with no diketopiperazine formation in sequences prone to this side reaction; on-resin cyclization without the concourse of common organic reagents such as Pd(0) but of difficult use in a biological laboratory; and on-resin disulfide formation in a total side-chain unprotected peptide. The use of Mmsb linker together with Msib (4-(methylsulfinyl)benzyl) and Msbh (4,4'-bis(methylsulfinyl)benzhydryl) described in the accompanying manuscript add a fourth dimension to the SPPS protecting group scheme.
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Affiliation(s)
- K P Nandhini
- Peptide Science Laboratory, School of Chemistry and Physics, University of KwaZulu-Natal, Westville, Durban 4000, South Africa.,KwaZulu-Natal Research Innovation and Sequencing Platform (KRISP), School of Laboratory Medicine and Medical Sciences, College of Health Sciences, University of KwaZulu-Natal, Durban 4041, South Africa
| | - Fernando Albericio
- Peptide Science Laboratory, School of Chemistry and Physics, University of KwaZulu-Natal, Westville, Durban 4000, South Africa.,Institute for Advanced Chemistry of Catalonia (IQAC-CSIC), Jordi Girona 18-26, 08034 Barcelona, Spain.,CIBER-BBN, Networking Centre on Bioengineering, Biomaterials and Nanomedicine, and Department of Organic Chemistry, University of Barcelona, Martí i Franqués 1-11, 08028 Barcelona, Spain
| | - Beatriz G de la Torre
- KwaZulu-Natal Research Innovation and Sequencing Platform (KRISP), School of Laboratory Medicine and Medical Sciences, College of Health Sciences, University of KwaZulu-Natal, Durban 4041, South Africa
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6
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Avdeev DV, Ovchinnikov MV, Dudkina YS, Molokoedov AS, Azmuko AA, Palkeeva ME, Sidorova MV. Optimal Method for Disulfide Bond Closure in the Synthesis of Atosiban—Antagonist of Oxytocin Receptors. RUSSIAN JOURNAL OF BIOORGANIC CHEMISTRY 2021. [DOI: 10.1134/s1068162021060042] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Abstract
This work is devoted to the large-scale solid-phase synthesis (SPS) of Atosiban, Mpa1-D-Tyr(OEt)-Ile-Thr-Asn-Cys6-Pro-Orn-Gly-NH2 cyclic 1,6 disulfide, the only clinically used oxytocin receptor antagonist. The conditions have been selected for the closure of the disulfide bond (S–S) in the Atosiban molecule both in the solution and solid phase with the minimal formation of by-products. A comparative assessment of the formation of the S–S bond was carried out under various conditions. The formation of by-products during the closure of the disulfide bond has been studied both in solution and on the polymer support. The developed technique allows for the synthesis of Atosiban on an enlarged scale (10–20 mmol) involving the cyclization of a protected intermediate with the formation of the S–S bond during solid-phase synthesis with the minimal formation of by-products.
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7
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Chakraborty A, Albericio F, de la Torre BG. Chemoselective Disulfide Formation by Thiol-Disulfide Interchange in SIT-Protected Cysteinyl Peptides. J Org Chem 2021; 87:708-712. [PMID: 34910477 DOI: 10.1021/acs.joc.1c02705] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Chemoselective disulfide formation is accomplished through a thiol-disulfide interchange approach using sec-isoamyl mercaptan (SIT) as an alkyl sulfenyl-protecting group of one of the Cys residues involved in the pairing. SIT has a dual and unique characteristic, acting as a masking group during the synthesis and directing disulfide formation in the presence of a free thiol. This novel approach is illustrated by the synthesis of several peptides of biological interest.
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Affiliation(s)
- Amit Chakraborty
- Peptide Science Laboratory, School of Chemistry and Physics, University of KwaZulu-Natal, Durban 4001, South Africa
| | - Fernando Albericio
- Peptide Science Laboratory, School of Chemistry and Physics, University of KwaZulu-Natal, Durban 4001, South Africa.,Institute for Advanced Chemistry of Catalonia (IQAC-CSIC), Barcelona 08034, Spain.,CIBER-BBN, Networking Centre on Bioengineering, Biomaterials and Nanomedicine, and Department of Organic Chemistry, University of Barcelona, Barcelona 08028, Spain
| | - Beatriz G de la Torre
- KwaZulu-Natal Research Innovation and Sequencing Platform (KRISP), School of Laboratory of Medicine and Medical Sciences, University of KwaZulu-Natal, Durban 4041, South Africa
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8
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Kobayashi K, Taguchi A, Cui Y, Shida H, Muguruma K, Takayama K, Taniguchi A, Hayashi Y. “On‐Resin” Disulfide Peptide Synthesis with Methyl 3‐Nitro‐2‐pyridinesulfenate. European J Org Chem 2021. [DOI: 10.1002/ejoc.202001517] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Kiyotaka Kobayashi
- Department of Medicinal chemistry School of Pharmacy Tokyo University of Pharmacy and Life Sciences 1432-1 Horinouchi Hachioji, Tokyo 192–0392 Japan
| | - Akihiro Taguchi
- Department of Medicinal chemistry School of Pharmacy Tokyo University of Pharmacy and Life Sciences 1432-1 Horinouchi Hachioji, Tokyo 192–0392 Japan
| | - Yan Cui
- Department of Medicinal chemistry School of Pharmacy Tokyo University of Pharmacy and Life Sciences 1432-1 Horinouchi Hachioji, Tokyo 192–0392 Japan
| | - Hayate Shida
- Department of Medicinal chemistry School of Pharmacy Tokyo University of Pharmacy and Life Sciences 1432-1 Horinouchi Hachioji, Tokyo 192–0392 Japan
| | - Kyohei Muguruma
- Department of Medicinal chemistry School of Pharmacy Tokyo University of Pharmacy and Life Sciences 1432-1 Horinouchi Hachioji, Tokyo 192–0392 Japan
| | - Kentaro Takayama
- Department of Medicinal chemistry School of Pharmacy Tokyo University of Pharmacy and Life Sciences 1432-1 Horinouchi Hachioji, Tokyo 192–0392 Japan
| | - Atsuhiko Taniguchi
- Department of Medicinal chemistry School of Pharmacy Tokyo University of Pharmacy and Life Sciences 1432-1 Horinouchi Hachioji, Tokyo 192–0392 Japan
| | - Yoshio Hayashi
- Department of Medicinal chemistry School of Pharmacy Tokyo University of Pharmacy and Life Sciences 1432-1 Horinouchi Hachioji, Tokyo 192–0392 Japan
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9
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Yang Y, Hansen L, Badalassi F. Investigation of On-Resin Disulfide Formation for Large-Scale Manufacturing of Cyclic Peptides: A Case Study. Org Process Res Dev 2020. [DOI: 10.1021/acs.oprd.0c00168] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Affiliation(s)
- Yi Yang
- Chemical Development, Global Pharmaceutical R&D, Ferring Pharmaceuticals A/S, Kay Fiskers Plads 11, DK-2300 Copenhagen S, Denmark
| | - Lena Hansen
- Chemical Development, Global Pharmaceutical R&D, Ferring Pharmaceuticals A/S, Kay Fiskers Plads 11, DK-2300 Copenhagen S, Denmark
| | - Fabrizio Badalassi
- Chemical Development, Global Pharmaceutical R&D, Ferring Pharmaceuticals A/S, Kay Fiskers Plads 11, DK-2300 Copenhagen S, Denmark
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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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Loh SH, Chang CY, Huang SF, Chao SC, Lin WK, Huang EYK, Tsai CS, Tsai YT. Functional effects of urotensin-II on intracellular pH regulators in human radial artery smooth muscle cells. Peptides 2020; 126:170236. [PMID: 31874233 DOI: 10.1016/j.peptides.2019.170236] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/06/2019] [Revised: 12/11/2019] [Accepted: 12/16/2019] [Indexed: 02/04/2023]
Abstract
The regulation of intracellular pH (pHi) plays a vital role in various cellular functions. We previously demonstrated that three different acid extruders, the Na+-H+ exchanger (NHE), Na+-HCO3- co-transporter (NBC) and H+-linked monocarboxylate transporter (MCT), functioned together in cultured human radial artery smooth muscle cells (HRASMCs). However, the functions of acid-loading transporters in HRASMCs remain poorly understood. Urotensin II (U-II), one of the most potent vasoconstrictors, is highly expressed in many cardiovascular diseases. The aim of this present study was to determine the concentration effect of U-II (3 pM∼100 nM) on the functional activity of pHi regulators in HRASMCs. Cultured HRASMCs were derived from segments of human radial arteries obtained from patients undergoing bypass grafting. Changes in pHi recovery due to intracellular acidification and alkalization induced by NH4Cl prepulse and Na-acetate prepulse, respectively, were detected by microspectrofluorimetry with the pH-sensitive fluorescent dye BCECF. Our present study showed that (a) U-II increased the activity of NHE in a concentration-dependent manner but did not change that of NBC or MCT or resting pHi, (b) the Cl--OH- exchanger (CHE) facilitated base extrusion, and (c) U-II induced a concentration-dependent increase in the activity of CHE. In conclusion, for the first time, our results highlight a concentration-dependent increase in the activity of NHE and CHE, but not NBC and MCT, induced by U-II in HRASMCs.
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Affiliation(s)
- Shih-Hurng Loh
- Department of Pharmacology, National Defense Medical Center, Taipei, 11490, Taiwan; Department of Pharmacy Practice, Tri-Service General Hospital, National Defense Medical Center, Taipei, 11490, Taiwan; Graduate Institute of Life Sciences, National Defense Medical Center, Taipei, 11490, Taiwan.
| | - Chung-Yi Chang
- Department of General Surgery, Cheng-Hsieng General Hospital, Taipei, 11200, Taiwan.
| | - Shu-Fu Huang
- Department of Pharmacy Practice, Tri-Service General Hospital, National Defense Medical Center, Taipei, 11490, Taiwan.
| | - Shih-Chi Chao
- Graduate Institute of Life Sciences, National Defense Medical Center, Taipei, 11490, Taiwan.
| | - Wei-Kuo Lin
- Department of Pharmacology, National Defense Medical Center, Taipei, 11490, Taiwan.
| | - Eagle Yi-Kung Huang
- Department of Pharmacology, National Defense Medical Center, Taipei, 11490, Taiwan.
| | - Chien-Sung Tsai
- Department of Pharmacology, National Defense Medical Center, Taipei, 11490, Taiwan; Division of Cardiovascular Surgery, Department of Surgery, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan.
| | - Yi-Ting Tsai
- Division of Cardiovascular Surgery, Department of Surgery, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan.
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12
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Shen X, Huang C, Shinde S, Jagadeesan KK, Ekström S, Fritz E, Sellergren B. Catalytic Formation of Disulfide Bonds in Peptides by Molecularly Imprinted Microgels at Oil/Water Interfaces. ACS APPLIED MATERIALS & INTERFACES 2016; 8:30484-30491. [PMID: 27750005 DOI: 10.1021/acsami.6b10131] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
This work describes the preparation and investigation of molecularly imprinted polymer (MIP) microgel (MG) stabilized Pickering emulsions (PEs) for their ability to catalyze the formation of disulfide bonds in peptides at the O/W interface. The MIP MGs were synthesized via precipitation polymerization and a programmed initiator change strategy. The MIP MGs were characterized using DLS analysis, SEM measurement, and optical microscopy analysis. The dry and wet MIP MGs showed a hydrodynamic diameter of 100 and 280 nm, respectively. A template rebinding experiment showed that the MIP MGs bound over two times more template (24 mg g-1) compared to the uptake displayed by a nonimprinted reference polymer (NIP) MG (10 mg g-1) at saturation. Using the MIP MGs as stabilizers, catalytic oxidation systems were prepared by emulsifying the oil phase and water phase in the presence of different oxidizing agents. During the cyclization, the isolation of the thiol precursors and the oxidizing reagents nonselectively decreased the formation of the byproducts, while the imprinted cavities on the MIP MGs selectively promoted the intramolecular cyclization of peptides. When I2 was used as the oxidizing agent, the MIP-PE-I2 system showed a product yield of 50%, corresponding to a nearly 2-fold increase compared to that of the nonimprinted polymer NIP-PE-I2 system (26%). We believe the interfacial catalysis system presented in this work may offer significant benefits in synthetic peptide chemistry by raising productivity while suppressing the formation of byproducts.
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Affiliation(s)
- Xiantao Shen
- Key Laboratory of Environment and Health, Ministry of Education & Ministry of Environmental Protection, State Key Laboratory of Environmental Health (Incubation), School of Public Health, Tongji Medical College, Huazhong University of Science and Technology , Hangkong Road #13, Wuhan, Hubei 430030, China
- Department of Biomedical Sciences, Faculty of Health and Society, Malmö University , SE20506 Malmö, Sweden
- G&T Septech AS , P.O. Box 33, 1917 Ytre Enebakk, Norway
| | - Chuixiu Huang
- Department of Biomedical Sciences, Faculty of Health and Society, Malmö University , SE20506 Malmö, Sweden
- School of Pharmacy, University of Oslo , P.O. Box 1068, 0316 Blindern Oslo, Norway
- G&T Septech AS , P.O. Box 33, 1917 Ytre Enebakk, Norway
| | - Sudhirkumar Shinde
- Department of Biomedical Sciences, Faculty of Health and Society, Malmö University , SE20506 Malmö, Sweden
| | | | - Simon Ekström
- Department of Biomedical Engineering, Lund University , 221 00 Lund, Sweden
| | - Emelie Fritz
- INFU, Technische Universität Dortmund , 44221 Dortmund, Germany
| | - Börje Sellergren
- Department of Biomedical Sciences, Faculty of Health and Society, Malmö University , SE20506 Malmö, Sweden
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13
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Kotamraju VR, Sharma S, Kolhar P, Agemy L, Pavlovich J, Ruoslahti E. Increasing Tumor Accessibility with Conjugatable Disulfide-Bridged Tumor-Penetrating Peptides for Cancer Diagnosis and Treatment. BREAST CANCER-BASIC AND CLINICAL RESEARCH 2015; 9:79-87. [PMID: 27385913 PMCID: PMC4924884 DOI: 10.4137/bcbcr.s29426] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/03/2015] [Revised: 11/01/2015] [Accepted: 11/02/2015] [Indexed: 01/24/2023]
Abstract
Tumor-homing peptides with tissue-penetrating properties increase the efficacy of targeted cancer therapy by delivering an anticancer agent to the tumor interior. LyP-1 (CGNKRTRGC) and iRGD (CRGDKGPDC) are founding members of this class of peptides. The presence of the cysteines forming the cyclizing disulfide bond complicates conjugation of these peptides with other molecules, such as drugs. Here, we report the synthesis of conjugatable disulfide-bridged peptides and their conjugation to biologically important molecules. We have synthesized the LyP-1, iRGD, and CRGDC (GACRGDCLGA) peptides with a cysteine or maleimidohexanoic acid added externally at N-terminus of the sequences. Subsequent conjugation to payloads yielded stable compounds in which the tumor-homing properties of the peptide and the biological activity of the payload were retained.
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Affiliation(s)
- Venkata Ramana Kotamraju
- Cancer Research Center, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA, USA.; Department of Molecular, Cellular, and Developmental Biology, Center for Nanomedicine, University of California, Santa Barbara, Santa Barbara, CA, USA
| | - Shweta Sharma
- Cancer Research Center, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA, USA
| | - Poornima Kolhar
- Department of Biomolecular Science and Engineering, University of California, Santa Barbara, Santa Barbara, CA, USA
| | - Lilach Agemy
- Department of Plant Sciences, Weizmann Institute of Science, Rehovot, Israel
| | - James Pavlovich
- Department of Chemistry and Biochemistry, University of California, Santa Barbara, Santa Barbara, CA, USA
| | - Erkki Ruoslahti
- Cancer Research Center, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA, USA.; Department of Molecular, Cellular, and Developmental Biology, Center for Nanomedicine, University of California, Santa Barbara, Santa Barbara, CA, USA
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14
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Hurevich M, Kandasamy J, Ponnappa BM, Collot M, Kopetzki D, McQuade DT, Seeberger PH. Continuous Photochemical Cleavage of Linkers for Solid-Phase Synthesis. Org Lett 2014; 16:1794-7. [DOI: 10.1021/ol500530q] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Affiliation(s)
- Mattan Hurevich
- Max Planck Institute of Colloids and Interfaces Am Mühlenberg 1, 14476 Potsdam Germany
| | - Jeyakumar Kandasamy
- Max Planck Institute of Colloids and Interfaces Am Mühlenberg 1, 14476 Potsdam Germany
| | - Bopanna M. Ponnappa
- Max Planck Institute of Colloids and Interfaces Am Mühlenberg 1, 14476 Potsdam Germany
- Institute
of Chemistry and Biochemistry, Freie Universität Berlin, Arnimallee 22, 14195 Berlin Germany
| | - Mayeul Collot
- Max Planck Institute of Colloids and Interfaces Am Mühlenberg 1, 14476 Potsdam Germany
| | - Daniel Kopetzki
- Max Planck Institute of Colloids and Interfaces Am Mühlenberg 1, 14476 Potsdam Germany
| | - D. Tyler McQuade
- Max Planck Institute of Colloids and Interfaces Am Mühlenberg 1, 14476 Potsdam Germany
- Department
of Chemistry and Biochemistry, Florida State University, Tallahassee, Florida 32306, United States
| | - Peter H. Seeberger
- Max Planck Institute of Colloids and Interfaces Am Mühlenberg 1, 14476 Potsdam Germany
- Institute
of Chemistry and Biochemistry, Freie Universität Berlin, Arnimallee 22, 14195 Berlin Germany
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15
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Burkovitz A, Leiderman O, Sela-Culang I, Byk G, Ofran Y. Computational Identification of Antigen-Binding Antibody Fragments. THE JOURNAL OF IMMUNOLOGY 2013; 190:2327-34. [DOI: 10.4049/jimmunol.1200757] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
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16
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Tada Y, Yamamoto T, Tezuka Y, Kawamoto T, Mori T. Effective Synthesis and Crystal Structure of a 24-Membered Cyclic Decanedisulfide Dimer. CHEM LETT 2012. [DOI: 10.1246/cl.2012.1678] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Affiliation(s)
- Yukihiro Tada
- Department of Organic and Polymeric Materials, Tokyo Institute of Technology
| | - Takuya Yamamoto
- Department of Organic and Polymeric Materials, Tokyo Institute of Technology
| | - Yasuyuki Tezuka
- Department of Organic and Polymeric Materials, Tokyo Institute of Technology
| | - Tadashi Kawamoto
- Department of Organic and Polymeric Materials, Tokyo Institute of Technology
| | - Takehiko Mori
- Department of Organic and Polymeric Materials, Tokyo Institute of Technology
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17
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Zheng JS, Tang S, Guo Y, Chang HN, Liu L. Synthesis of Cyclic Peptides and Cyclic Proteins via Ligation of Peptide Hydrazides. Chembiochem 2012; 13:542-6. [DOI: 10.1002/cbic.201100580] [Citation(s) in RCA: 77] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2011] [Indexed: 02/01/2023]
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18
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Schwefel D, Maierhofer C, Beck JG, Seeberger S, Diederichs K, Möller HM, Welte W, Wittmann V. Structural basis of multivalent binding to wheat germ agglutinin. J Am Chem Soc 2010; 132:8704-19. [PMID: 20527753 DOI: 10.1021/ja101646k] [Citation(s) in RCA: 159] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The inhibition of carbohydrate-protein interactions by tailored multivalent ligands is a powerful strategy for the treatment of many human diseases. Crucial for the success of this approach is an understanding of the molecular mechanisms as to how a binding enhancement of a multivalent ligand is achieved. We have synthesized a series of multivalent N-acetylglucosamine (GlcNAc) derivatives and studied their interaction with the plant lectin wheat germ agglutinin (WGA) by an enzyme-linked lectin assay (ELLA) and X-ray crystallography. The solution conformation of one ligand was determined by NMR spectroscopy. Employing a GlcNAc carbamate motif with alpha-configuration and by systematic variation of the spacer length, we were able to identify divalent ligands with unprecedented high WGA binding potency. The best divalent ligand has an IC(50) value of 9.8 microM (ELLA) corresponding to a relative potency of 2350 (1170 on a valency-corrected basis, i.e., per mol sugar contained) compared to free GlcNAc. X-ray crystallography of the complex of WGA and the second best, closely related divalent ligand explains this activity. Four divalent molecules simultaneously bind to WGA with each ligand bridging adjacent binding sites. This shows for the first time that all eight sugar binding sites of the WGA dimer are simultaneously functional. We also report a tetravalent neoglycopeptide with an IC(50) value of 0.9 microM being 25,500 times higher than that of GlcNAc (6400 times per contained sugar) and the X-ray structure analysis of its complex with glutaraldehyde-cross-linked WGA. Comparison of the crystal structure and the solution NMR structure of the neoglycopeptide as well as results from the ELLA suggest that the conformation of the glycopeptide in solution is already preorganized in a way supporting multivalent binding to the protein. Our findings show that bridging adjacent protein binding sites by multivalent ligands is a valid strategy to find high-affinity protein ligands and that even subtle changes of the linker structure can have a significant impact on the binding affinity.
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19
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Friligou I, Papadimitriou E, Gatos D, Matsoukas J, Tselios T. Microwave-assisted solid-phase peptide synthesis of the 60-110 domain of human pleiotrophin on 2-chlorotrityl resin. Amino Acids 2010; 40:1431-40. [PMID: 20872260 DOI: 10.1007/s00726-010-0753-6] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2010] [Accepted: 09/10/2010] [Indexed: 11/26/2022]
Abstract
A fast and efficient microwave-assisted solid phase peptide synthesis (MW-SPPS) of a 51mer peptide, the main heparin-binding site (60-110) of human pleiotrophin (hPTN), using 2-chlorotrityl chloride resin (CLTR-Cl) following the 9-fluorenylmethyloxycarbonyl/tert-butyl (Fmoc/tBu) methodology and with the standard N,N'-diisopropylcarbodiimide/1-hydroxybenzotriazole (DIC/HOBt) coupling reagents, is described. An MW-SPPS protocol was for the first time successfully applied to the acid labile CLTR-Cl for the faster synthesis of long peptides (51mer peptide) and with an enhanced purity in comparison to conventional SPPS protocols. The synthesis of such long peptides is not trivial and it is generally achieved by recombinant techniques. The desired linear peptide was obtained in only 30 h of total processing time and in 51% crude yield, in which 60% was the purified product obtained with 99.4% purity. The synthesized peptide was purified by reversed phase high performance liquid chromatography (RP-HPLC) and identified by electrospray ionization mass spectrometry (ESI-MS). Then, the regioselective formation of the two disulfide bridges of hPTN 60-110 was successfully achieved by a two-step procedure, involving an oxidative folding step in dimethylsulfoxide (DMSO) to form the Cys(77)-Cys(109) bond, followed by iodine oxidation to form the Cys(67)-Cys(99) bond.
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Affiliation(s)
- Irene Friligou
- Department of Chemistry, University of Patras, 265 04, Patras, Greece
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20
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Góngora-Benítez M, Tulla-Puche J, Paradís-Bas M, Werbitzky O, Giraud M, Albericio F. Optimized Fmoc solid-phase synthesis of the cysteine-rich peptide linaclotide. Biopolymers 2010; 96:69-80. [DOI: 10.1002/bip.21480] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2010] [Revised: 03/27/2010] [Accepted: 04/19/2010] [Indexed: 11/11/2022]
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21
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Galanis AS, Albericio F, Grøtli M. Enhanced microwave-assisted method for on-bead disulfide bond formation: synthesis of alpha-conotoxin MII. Biopolymers 2009; 92:23-34. [PMID: 19003899 DOI: 10.1002/bip.21116] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
A novel enhanced microwave-assisted disulfide bridge formation method has been developed. To optimize the synthesis of the biologically important bicyclic peptide alpha-conotoxin MII (alpha-CtxMII), several cyclization methods have been tested and are discussed herein. By using m.w.-assisted heating, we achieved high yields for the first loop cyclization of alpha-CtxMII on-bead. This method has the advantage of avoiding intermolecular by-products during the cyclization step. Furthermore, the method gives higher yields compared with the common on-bead cyclization methods. The second disulfide bridge of alpha-CtxMII was formed using a simple oxidation method after the cleavage of the intermediate monocyclic peptide from the resin. This method has the potential to be efficient for the synthesis of other disulfide rich biologically important peptides.
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Affiliation(s)
- Athanassios S Galanis
- Department of Chemistry, Medicinal Chemistry, University of Göteborg, SE-41296 Göteborg, Sweden
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22
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Agnes RS, Ying J, Kövér KE, Lee YS, Davis P, Ma SW, Badghisi H, Porreca F, Lai J, Hruby VJ. Structure-activity relationships of bifunctional cyclic disulfide peptides based on overlapping pharmacophores at opioid and cholecystokinin receptors. Peptides 2008; 29:1413-23. [PMID: 18502541 PMCID: PMC2601673 DOI: 10.1016/j.peptides.2008.03.022] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/05/2008] [Revised: 03/26/2008] [Accepted: 03/27/2008] [Indexed: 11/24/2022]
Abstract
Prolonged opioid exposure increases the expression of cholecystokinin (CCK) and its receptors in the central nervous system (CNS), where CCK may attenuate the antinociceptive effects of opioids. The complex interactions between opioid and CCK may play a role in the development of opioid tolerance. We designed and synthesized cyclic disulfide peptides and determined their agonist properties at opioid receptors and antagonist properties at CCK receptors. Compound 1 (Tyr-c[d-Cys-Gly-Trp-Cys]-Asp-Phe-NH(2)) showed potent binding and agonist activities at delta and mu opioid receptors but weak binding to CCK receptors. The NMR structure of the lead compound displayed similar conformational features of opioid and CCK ligands.
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Affiliation(s)
- Richard S. Agnes
- Department of Chemistry, University of Arizona, Tucson, AZ 85721
| | - Jinfa Ying
- Department of Chemistry, University of Arizona, Tucson, AZ 85721
| | - Katalin E. Kövér
- Department of Chemistry, University of Debrecen, H-4010 Debrecen, P.O. Box 21, Egyetem tér 1, Hungary
| | - Yeon Sun Lee
- Department of Chemistry, University of Arizona, Tucson, AZ 85721
| | - Peg Davis
- Department of Pharmacology, University of Arizona, Tucson, AZ 85724
| | - Shou-wu Ma
- Department of Pharmacology, University of Arizona, Tucson, AZ 85724
| | - Hamid Badghisi
- Department of Pharmacology, University of Arizona, Tucson, AZ 85724
| | - Frank Porreca
- Department of Pharmacology, University of Arizona, Tucson, AZ 85724
| | - Josephine Lai
- Department of Pharmacology, University of Arizona, Tucson, AZ 85724
| | - Victor J. Hruby
- Department of Chemistry, University of Arizona, Tucson, AZ 85721
- To whom correspondence should be addressed: Victor J. Hruby, Department of Chemistry, University of Arizona, Tucson, AZ 85721, USA. Phone: (520) 621-6332. Fax: (520) 621-8407.,
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23
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Abstract
The formation of disulfide bridges is often a crucial final stage in peptide synthesis. There is compelling evidence that the disulfide pattern can be critical in the folding and structural stabilization of many natural peptide and protein sequences, while the artificial introduction of disulfide bridges into natural or designed peptides may often improve biological activities/specificities and stabilities. This unit provides a highly selective, albeit state-of-the-art, menu of procedures that can be performed to establish intramolecular or intermolecular disulfide bridges in targets of varying complexities.
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Affiliation(s)
- L Chen
- AxCell Biosciences Corporation, Newtown, Pennsylvania, USA
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24
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Malešević M, Jahreis G, Wawra S, Fischer G, Lücke C. Conformational Consequences of Regio- and Stereoselective Disulfide Bridge Oxidation in a Cyclic Peptide. Chembiochem 2008; 9:46-9. [DOI: 10.1002/cbic.200700529] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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25
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Kudryavtseva EV, Sidorova MV, Evstigneeva RP. Some peculiarities of synthesis of cysteine-containing peptides. RUSSIAN CHEMICAL REVIEWS 2007. [DOI: 10.1070/rc1998v067n07abeh000424] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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26
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Borics A, Murphy RF, Lovas S. Optical spectroscopic elucidation of beta-turns in disulfide bridged cyclic tetrapeptides. Biopolymers 2007; 85:1-11. [PMID: 16948119 DOI: 10.1002/bip.20593] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Vibrational circular dichroism (VCD) spectroscopic features of type II beta-turns were characterized previously, but, criteria for differentiation between beta-turn types had not been established yet. Model tetrapeptides, cyclized through a disulfide bridge, were designed on the basis of previous experimental results and the observed incidence of amino acid residues in the i + 1 and i + 2 positions in beta-turns, to determine the features of VCD spectra of type I and II beta-turns. The results were correlated with electronic circular dichroism (ECD) spectra and VCD spectra calculated from conformational data obtained by molecular dynamics (MD) simulations. All cyclic tetrapeptides yielded VCD signals with a higher frequency negative and a lower frequency positive couplet with negative lobes overlapping. MD simulations confirmed the conformational homogeneity of these peptides in solution. Comparison with ECD spectroscopy, MD, and quantum chemical calculation results suggested that the low frequency component of VCD spectra originating from the tertiary amide vibrations could be used to distinguish between types of beta-turn structures. On the basis of this observation, VCD spectroscopic features of type II and VIII beta-turns and ECD spectroscopic properties of a type VIII beta-turn were suggested. The need for independent experimental as well as theoretical investigations to obtain decisive conformational information was recognized.
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Affiliation(s)
- Attila Borics
- Department of Biomedical Sciences, Creighton University Medical Center, Omaha, NE 68178, USA
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27
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Bayó-Puxan N, Fernández A, Tulla-Puche J, Riego E, Álvarez M, Albericio F. Beyond Azathiocoraline: Synthesis of Analogues. Int J Pept Res Ther 2007. [DOI: 10.1007/s10989-007-9080-5] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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28
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Bayó-Puxan N, Fernández A, Tulla-Puche J, Riego E, Cuevas C, Alvarez M, Albericio F. Total Solid-Phase Synthesis of the Azathiocoraline Class of Symmetric Bicyclic Peptides. Chemistry 2006; 12:9001-9. [PMID: 16953505 DOI: 10.1002/chem.200600815] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Thiocoraline is a potent antitumor agent isolated from the marine organism Micromonospora sp. This symmetric bicyclic depsipeptide binds the minor groove of DNA. Here we report two solid-phase strategies for the syntheses of azathiocoraline and its analogues. The thioester linkage was replaced by an amide bond to improve the compound's pharmacokinetic properties. The first strategy is based on a convergent (4+4) approach, whilst the second is a stepwise synthesis, cyclizations in both approaches occurring on the solid support. These two strategies were designed to overcome problems caused by the presence of consecutive noncommercial N-methyl amino acids, to avoid epimerization during cyclization and/or fragment condensation, and to form the disulfide bridge under solid-phase conditions. The heterocyclic moiety was added in the last step of the synthesis to assist the preparation of libraries of new compounds with potential therapeutic applications.
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Affiliation(s)
- Núria Bayó-Puxan
- Barcelona Biomedical Research Institute, University of Barcelona, Barcelona Science Park (PCB), 08028 Barcelona, Spain
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29
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Abedini A, Singh G, Raleigh DP. Recovery and purification of highly aggregation-prone disulfide-containing peptides: application to islet amyloid polypeptide. Anal Biochem 2005; 351:181-6. [PMID: 16406209 DOI: 10.1016/j.ab.2005.11.029] [Citation(s) in RCA: 69] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2005] [Revised: 11/21/2005] [Accepted: 11/21/2005] [Indexed: 11/25/2022]
Abstract
Islet amyloid polypeptide (IAPP) is a 37-residue pancreatic hormone. It is responsible for the formation of islet amyloid in vivo and is very insoluble and aggregation-prone in vitro, particularly at basic pH. The peptide contains a disulfide bridge between residues two and seven and an amidated C terminus. There is no reported expression system for the production of amidated IAPP. The peptide is difficult to synthesize and formation of the disulfide by traditional methods is problematic. We have found that the use of 1,1,1,3,3,3-hexafluoro-2-propanol (HFIP) or dimethyl sulfoxide (DMSO) significantly improves disulfide formation and purification of highly aggregation-prone IAPP sequences. The use of these organic solvents increases the solubility of the hydrophobic peptides, avoids the use of aqueous basic solutions, and eliminates the need for continuous stirring during oxidation to form the Cys-2 to Cys-7 disulfide bridge. Elimination of the stirring step and basic solution helps to reduce aggregation and allows for more consistent high-performance liquid chromatography (HPLC) retention times. Formation of the intramolecular disulfide using DMSO was found to be the most effective method for IAPP oxidation, reducing the reaction time from 24 to 5 h. Aggregated IAPP can be resolubilized by HFIP or DMSO and recovered by HPLC with very good yield.
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Affiliation(s)
- Andisheh Abedini
- Department of Chemistry, State University of New York at Stony Brook, Stony Brook, NY 11794-3400, USA.
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30
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Wickstrom E, Thakur ML, Sauter ER. Receptor-specific targeting with complementary peptide nucleic acids conjugated to peptide analogs and radionuclides. Int J Pept Res Ther 2005. [DOI: 10.1007/s10989-005-4917-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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31
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Smith CA, Hinman CL. Evidence that L1AD3, an apoptosis-inducing cyclic peptide, binds a leukemic T-cell membrane protein receptor. Arch Biochem Biophys 2004; 432:88-101. [PMID: 15519300 DOI: 10.1016/j.abb.2004.08.010] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2004] [Revised: 08/11/2004] [Indexed: 12/18/2022]
Abstract
Human leukemic T-lymphocytes undergo extensive and rapid apoptosis in the presence of L1AD3, a small cyclic peptide derivative of cobra cardiotoxin. The first step in this process involves its binding to membranes of susceptible cells. By the use of a biotin "handle" synthetically incorporated at the N-terminus of L1AD3, we show that binding is saturable and selective: normal human peripheral blood lymphocytes do not bind this peptide. Fluorescence resonance energy transfer experiments indicate that the binding sites are separated by at least 55 A. Loss of binding occurs if membrane proteins are enzymatically degraded, suggesting that L1AD3's target is a cell-membrane surface protein receptor. Finally, crosslinking of cyclic BTNL1AD3 peptide to a leukemic T-cell membrane surface receptor, as examined using a biotin-avidin blot, indicated a molecular weight of approximately 34,400.
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Affiliation(s)
- Charles A Smith
- Department of Medicinal and Biological Chemistry, College of Pharmacy, The University of Toledo, 2801 W. Bancroft, Wolfe Hall, Toledo, OH 43606, USA.
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32
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Chatenet D, Dubessy C, Leprince J, Boularan C, Carlier L, Ségalas-Milazzo I, Guilhaudis L, Oulyadi H, Davoust D, Scalbert E, Pfeiffer B, Renard P, Tonon MC, Lihrmann I, Pacaud P, Vaudry H. Structure-activity relationships and structural conformation of a novel urotensin II-related peptide. Peptides 2004; 25:1819-30. [PMID: 15476952 DOI: 10.1016/j.peptides.2004.04.019] [Citation(s) in RCA: 85] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/12/2004] [Accepted: 04/23/2004] [Indexed: 02/07/2023]
Abstract
Urotensin II (UII) has been described as the most potent vasoconstrictor peptide and recognized as the endogenous ligand of the orphan G protein-coupled receptor GPR14. Recently, a UII-related peptide (URP) has been isolated from the rat brain and its sequence has been established as H-Ala-Cys-Phe-Trp-Lys-Tyr-Cys-Val-OH. In order to study the structure-function relationships of URP, we have synthesized a series of URP analogs and measured their binding affinity on hGPR14-transfected cells and their contractile activity in a rat aortic ring bioassay. Alanine substitution of each residue of URP significantly reduced the binding affinity and the contractile activity of the peptides, except for the Ala8-substituted analog that retained biological activity. Most importantly, D-scan of URP revealed that [D-Trp4]URP abrogated and [D-Tyr6]URP partially suppressed the UII-evoked contractile response. [Orn5]URP, which had very low agonistic efficacy, was the most potent antagonist in this series. The solution structure of URP has been determined by 1H NMR spectroscopy and molecular dynamics. URP exhibited a single conformation characterized by an inverse gamma-turn comprising residues Trp-Lys-Tyr which plays a crucial role in the biological activity of URP. These pharmacological and structural data should prove useful for the rational design of non-peptide ligands as potential GPR14 agonists and antagonists.
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Affiliation(s)
- David Chatenet
- Laboratory of Cellular and Molecular Neuroendocrinology, European Institute for Peptide Research (IFRMP 23), INSERM U413, UA CNRS, University of Rouen, 76821 Mont-Saint-Aignan, France
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33
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Naider F, Becker JM. The alpha-factor mating pheromone of Saccharomyces cerevisiae: a model for studying the interaction of peptide hormones and G protein-coupled receptors. Peptides 2004; 25:1441-63. [PMID: 15374647 DOI: 10.1016/j.peptides.2003.11.028] [Citation(s) in RCA: 55] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/27/2003] [Accepted: 11/25/2003] [Indexed: 10/26/2022]
Abstract
Mating in Saccharomyces cerevisiae is initiated by the secretion of diffusible peptide pheromones that are recognized by G protein-coupled receptors (GPCR). This review summarizes the use of the alpha-factor (WHWLQLKPGQPMY)--GPCR (Ste2p) interaction as a paradigm to understand the recognition between medium-sized peptide hormones and their cognate receptors. Studies over the past 15 years have indicated that the alpha-factor is bent around the center of the pheromone and that residues near the amine terminus play a central role in triggering signal transduction. The bend in the center appears not to be rigid and this flexibility is likely necessary for conformational changes that occur as the receptor switches from the inactive to active state. The results of synthetic, biological, biochemical, molecular biological, and biophysical analyses have led to a preliminary model for the structure of the peptide bound to its receptor. Antagonists for Ste2p have changes near the N-terminus of alpha-factor, and mutated forms of Ste2p were discovered that appear to favor binding of these antagonists relative to agonists. Many features of this yeast recognition system are relevant to and have counterparts in mammalian cells.
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Affiliation(s)
- Fred Naider
- Department of Chemistry, College of Staten Island and Institute for Macromolecular Assemblies of The City University of New York, Staten Island, NY 10314, USA.
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34
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Tian X, Aruva MR, Rao PS, Qin W, Read P, Sauter ER, Thakur ML, Wickstrom E. Imaging oncogene expression. Ann N Y Acad Sci 2004; 1002:165-88. [PMID: 14751834 DOI: 10.1196/annals.1281.015] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
In 2003, approximately 39,800 women in the US will die from breast cancer. Mammography and physical examination miss up to 40% of early breast cancers. Moreover, if an abnormality is found, an invasive diagnostic procedure must still be performed to determine if the breast contains atypia or cancer, even though approximately 85% of abnormalities are benign. Scintigraphic imaging of gene expression in vivo by noninvasive means could direct physicians to appropriate targets for intervention at the onset of disease and thereby significantly impact patient management. Until now, no method has been available to image specific overexpressed oncogene mRNAs in vivo by scintigraphic imaging. We hypothesize that gamma-emitting Tc-99m-PNA-peptides can be taken up by human ER+ and ER- breast cancer xenografts, hybridize to complementary mRNA targets in those cells, and concentrate sufficiently in tumor tissue to allow noninvasive imaging of oncogene overexpression. To prepare the probes, peptide analogs of insulin-like growth factor 1 (IGF1) were extended from a solid support by Fmoc coupling. Peptide nucleic acid (PNA) dodecamers antisense to CCND1 and MYC mRNAs were then extended from the N-terminus of IGF1, followed by a chelator peptide, using Fmoc coupling for all residues. The cysteine thiols were cyclized on the solid support, either before or after PNA extension. This simplified synthetic approach allows preparation of a variety of multipeptide disulfide-bridged PNA chimeras. A chelating peptide-PNA chimera antisense to MYC mRNA was then labeled efficiently with Tc-99m, yielding a single product. Tissue distribution studies of antisense and mismatch chimeras at 4 h and 24 h after administration displayed modest accumulation in the liver and kidneys, with appreciable levels in tumors. This result enables testing of Tc-99m-peptide-PNA probes to image gene expression in tumors.
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Affiliation(s)
- Xiaobing Tian
- Department of Biochemistry Molecular Pharmacology, Thomas Jefferson University, Philadelphia, Pennsylvania 19107, USA
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35
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Smith CA, Hinman CL. A cyclic peptide, L1AD3, induces early signs of apoptosis in human leukemic T-cell lines. J Biochem Mol Toxicol 2004; 18:204-20. [PMID: 15452885 DOI: 10.1002/jbt.20025] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
L1AD3 is a small cyclic synthetic peptide designed to resemble the first loop of a cobra venom cytotoxin. Instead of inducing membrane disruption similar to that caused by the parent toxin, L1AD3 promotes extensive and unusually rapid apoptosis in leukemic T-cells without making the plasma membrane permeable to small fluorescent dyes. Within 4 h, micromolar concentrations of L1AD3 almost totally inhibit thymidine incorporation, and ATP levels decrease significantly. By contrast, normal human white blood cells are not affected by L1AD3, nor is heart cell function affected by it. If L1AD3 kills by interacting with targets that are different from those of currently applied agents, this peptide, or a derivative of it, could become a useful adjunct for cancer chemotherapy.
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Affiliation(s)
- Charles A Smith
- Department of Medicinal and Biological Chemistry, College of Pharmacy, The University of Toledo, Toledo, OH 43606, USA.
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36
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Lange UEW, Braje WM, Amberg W, Kettschau G. Solid-phase synthesis of endothelin receptor antagonists. Bioorg Med Chem Lett 2003; 13:1721-4. [PMID: 12729650 DOI: 10.1016/s0960-894x(03)00236-1] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
A new solid-phase synthesis for ET receptor antagonists suitable for automation is presented. A support bound 2-hydroxybutyric acid derivative was converted to the corresponding ether derivatives using 4-halo-2-methylsulfonylpyrimidines. Subsequent Suzuki coupling with various aryl boronic acids gave the desired antagonists in good yields and purities. Highly potent antagonists with excellent selectivity for ET(A) were obtained.
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37
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Wickstrom E, Thakur ML, Sauter ER. Receptor-specific targeting with complementary peptide nucleic acids conjugated to peptide analogs and radionuclides. Int J Pept Res Ther 2003. [DOI: 10.1007/bf02484559] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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38
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Tian X, Wickstrom E. Continuous solid-phase synthesis and disulfide cyclization of peptide-PNA-peptide chimeras. Org Lett 2002; 4:4013-6. [PMID: 12423074 DOI: 10.1021/ol026676b] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Chelator peptides were extended from the N-terminus of peptide nucleic acid (PNA) dodecamers, which in turn were extended from the N-termini of disulfide-bridged peptide ligand analogues, using Fmoc coupling for all residues. The cysteine thiols were cyclized on a solid support, either before or after PNA extension. This simplified synthetic approach might allow preparation of a variety of multipeptide disulfide-bridged PNA chimeras. [structure: see text]
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Affiliation(s)
- Xiaobing Tian
- Departments of Biochemistry & Molecular Pharmacology and Microbiology & Immunology, Kimmel Cancer Center, Thomas Jefferson University, Philadelphia, PA 19107, USA
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39
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Fajloun Z, Mosbah A, Carlier E, Mansuelle P, Sandoz G, Fathallah M, di Luccio E, Devaux C, Rochat H, Darbon H, De Waard M, Sabatier JM. Maurotoxin versus Pi1/HsTx1 scorpion toxins. Toward new insights in the understanding of their distinct disulfide bridge patterns. J Biol Chem 2000; 275:39394-402. [PMID: 10970898 DOI: 10.1074/jbc.m006810200] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Maurotoxin (MTX) is a scorpion toxin acting on several K(+) channel subtypes. It is a 34-residue peptide cross-linked by four disulfide bridges that are in an "uncommon" arrangement of the type C1-C5, C2-C6, C3-C4, and C7-C8 (versus C1-C5, C2-C6, C3-C7, and C4-C8 for Pi1 or HsTx1, two MTX-related scorpion toxins). We report here that a single mutation in MTX, in either position 15 or 33, resulted in a shift from the MTX toward the Pi1/HsTx1 disulfide bridge pattern. This shift is accompanied by structural and pharmacological changes of the peptide without altering the general alpha/beta scaffold of scorpion toxins.
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Affiliation(s)
- Z Fajloun
- CNRS UMR 6560, Boulevard Pierre Dramard, 13916 Marseille Cedex 20, the Architecture et Fonction des Macromolécules Biologiques, CNRS UPR 9039, 31 Chemin Joseph Aiguier, 13402 Marseille, France
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40
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Allylic protection of thiols and cysteine. III. Use of Fmoc-Cys(Fsam)-OH for solid-phase peptide synthesis. Int J Pept Res Ther 2000. [DOI: 10.1007/bf02447857] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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41
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Hargittai B, Barany G. Controlled syntheses of natural and disulfide-mispaired regioisomers of alpha-conotoxin SI. THE JOURNAL OF PEPTIDE RESEARCH : OFFICIAL JOURNAL OF THE AMERICAN PEPTIDE SOCIETY 1999; 54:468-79. [PMID: 10604592 DOI: 10.1034/j.1399-3011.1999.00127.x] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Methods are reported for the unambiguous syntheses of all three possible disulfide regioisomers with the sequence of alpha-conotoxin SI, a tridecapeptide amide from marine cone snail venom that binds selectively to the muscle subtype of nicotinic acetylcholine receptors. The naturally occurring peptide has two 'interlocking' disulfide bridges connecting Cys2-Cys7 and Cys3-Cys13 (2/7&3/13), while in the two mispaired isomers the disulfide bridges connect Cys2-Cys13 and Cys3-Cys7 (2/13 & 3/7, 'nested') and Cys2-Cys3 and Cys7-Cys13 (2/3 & 7/13, 'discrete'), respectively. Alignment of disulfide bridges was controlled at the level of orthogonal protection schemes for the linear precursors, assembled by Fmoc solid-phase peptide synthesis on acidolyzable tris(alkoxy)benzylamide (PAL) supports. Side-chain protection of cysteine was provided by suitable pairwise combination of the S-9H-xanthen-9-yl (Xan) and S-acetamidomethyl (Acm) protecting groups. The first disulfide bridge was formed from the corresponding bis(thiol) precursor obtained by selective deprotection of S-Xan, and the second disulfide bridge was formed by orthogonal co-oxidation of S-Acm groups on the remaining two Cys residues. It was possible to achieve the desired alignments with either order of loop formation (smaller loop before larger, or vice versa). The highest overall yields were obtained when both disulfides were formed in solution, while experiments where either the first or both bridges were formed while the peptide was on the solid support revealed lower overall yields and poorer selectivities towards the desired isomers.
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Affiliation(s)
- B Hargittai
- Department of Chemistry, University of Minnesota, Minneapolis 55455-0431, USA
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42
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Sheridan JM, Hayes GM, Austen BM. Solid-phase synthesis and cyclization of a large branched peptide from IgG Fc with affinity for Fc gammaRI. J Pept Sci 1999; 5:555-62. [PMID: 10628655 DOI: 10.1002/(sici)1099-1387(199912)5:12<555::aid-psc220>3.0.co;2-g] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
A solid phase approach has been used to synthesize a large branched disulphide peptide from IgG Fc, Ac-F-C*-A-K-V-N-N-K-D-L-P-A-P-I-E-K(Ac-E-L-L-G-G-P-S-V-F)-C*-I-NH2. This peptide combines the lower hinge region of IgG and a proximal beta-hairpin loop, both implicated in binding to Fc gammaRI. Solid phase Tl(tfa)3 cyclization of the linear branched peptide resulted in a poor yield of cyclic hinge-loop peptide (11%) most likely due to steric hindrance caused by the branch. However, if addition of the branch was preceded by solid phase Tl(tfa)3 cyclization of the loop, the yield was excellent at 75%. Cyclic hinge-loop peptide was active in displacing IgG2a from Fc gammaRI expressed on monocyte cell lines with an IC50 of 40 microM, whereas the linear form of this peptide was inactive. The Fc hinge-loop peptide demonstrates the potential for a non-mAb high affinity, immunomodulatory ligand for Fc gammaRI.
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Affiliation(s)
- J M Sheridan
- Department of Surgery, St George's Hospital Medical School, London, UK
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43
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Berezhkovskiy L, Pham S, Reich EP, Deshpande S. Synthesis and kinetics of cyclization of MHC class II-derived cyclic peptide vaccine for diabetes. THE JOURNAL OF PEPTIDE RESEARCH : OFFICIAL JOURNAL OF THE AMERICAN PEPTIDE SOCIETY 1999; 54:112-9. [PMID: 10461745 DOI: 10.1034/j.1399-3011.1999.00084.x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Conformationally constrained cyclic peptides are known to be better vaccines because of their ability to mimic the native structure of a protein against which an immune response is sought. To test the hypothesis of using conformationally constrained, disease-associated, MHC-derived peptides as vaccines for the prevention of type I diabetes, a 22 amino acid nonobese diabetic(NOD) mouse MHC class II-derived synthetic peptide was cyclized by the formation of end-to-end disulfide bonds and used to prevent diabetes and insulitis in NOD mice. The peptide was synthesized by Fmoc chemistry and cyclized using two methods: a commercially available cyclizing resin (Ekathiox) and air oxidation. When a 10 m excess of resin was used, the Ekathiox yielded a substantial amount of cyclic peptide with few or no side reactions. The kinetics of cyclization by air oxidation at different temperatures indicated that increasing both temperature and pH decreased the cyclization time significantly. Air oxidation at pH 10 at 37-55 degrees C yielded the desired product within 2 h.
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44
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45
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46
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Alsina J, Rabanal F, Chiva C, Giralt E, Albericio F. Active carbonate resins: Application to the solid-phase synthesis of alcohol, carbamate and cyclic peptides. Tetrahedron 1998. [DOI: 10.1016/s0040-4020(98)00606-1] [Citation(s) in RCA: 42] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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47
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Limal D, Briand JP, Dalbon P, Jolivet M. Solid-phase synthesis and on-resin cyclization of a disulfide bond peptide and lactam analogues corresponding to the major antigenic site of HIV gp41 protein. THE JOURNAL OF PEPTIDE RESEARCH : OFFICIAL JOURNAL OF THE AMERICAN PEPTIDE SOCIETY 1998; 52:121-9. [PMID: 9727868 DOI: 10.1111/j.1399-3011.1998.tb01366.x] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
A cyclic peptide that spans the major antigenic determinant of the human immunodeficiency virus (HIV) glycoprotein 41 (gp41) has been synthesized according to various strategies. For immunodiagnostic applications, biotin was added at the N-terminus of the peptide and aminohexanoic acid was used as a spacer. Polymer-supported oxidations were carried out in a variety of ways with thallium (III) trifluoroacetate. The biotinylcyclic peptide was released from the support using trimethylsilyl trifluoromethane sulfonate and various scavengers. The efficacy of these different cyclization and cleavage procedures was compared. Side reactions were studied, and a simple and efficient procedure was set up to monitor peptide cyclization by mass spectrometry. In a second series of syntheses the disulfide bridge was replaced by an amide bond. For this purpose, an aspartic acid derivative and a diaminopropionic acid were introduced during the synthesis in place of the two cysteine residues in the parent sequence. On-resin cyclization was performed and led to a major side-product identified as a piperidide. This undesired base-mediated side reaction was prevented when, instead of piperidine, 1,8-diazabicyclo-[5.4.0]undec-7-ene was used for fluorenylmethyl ester deprotection. Reactivity of these peptides with different patients' sera and with a monoclonal antibody directed against the whole gp41 was tested using an enzyme-linked immunosorbent assay.
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Affiliation(s)
- D Limal
- Institut de Biologie Moléculaire et Cellulaire, UPR 9021 CNRS, Strasbourg, France.
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48
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49
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Abstract
The goal of this review has been to present different chemical approaches for the formation of disulfide bonds in synthetic peptides and small proteins. Three general types of approaches have been described: (1) oxidation starting from the unprotected thiols; (2) oxidation starting from protected thiols; and (3) directed methods for formation of unsymmetrical disulfides. Individual or sequential disulfide-forming reactions can be carried out in solution or on a polymeric support. Overall yields and purities of products depends on protecting group combinations chosen, precise reaction conditions, and the targeted structure. Although no procedure can be guaranteed to give outstanding results for all cases, there are sufficient options available to support an optimistic view that one or more approaches can be optimized.
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Affiliation(s)
- I Annis
- Department of Chemistry, University of Minnesota, Minneapolis 55455, USA
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50
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Lal D, Mahale SD, Nandedkar TD, Iyer KS. Identification of bioneutralization epitopes of human follicle stimulating hormone in the regions 31-52 and 66-75 of its beta-subunit. J Reprod Immunol 1997; 33:1-14. [PMID: 9185072 DOI: 10.1016/s0165-0378(97)01016-4] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
The crucial role played by follicle stimulating hormone (FSH) in regulating both male and female reproduction and the possibilities of developing contraceptive methods for males by blocking the function of the hormone, makes it important to delineate the hormone-specific bioneutralization epitopes of human follicle stimulating hormone (hFSH) on its beta-subunit. Predictive methods were used to identify the potential surface-oriented regions of hFSH-beta. Peptides corresponding to these regions, i.e. 31-52, 66-75 and 86-95 hFSH-beta, were synthesized, anti-peptide antibodies were elicited in rabbits and the properties of these antisera to bind hFSH and neutralize its biological activity were assessed. Anti-31-52 hFSH-beta antisera bound hFSH specifically, whereas anti-66-75 and anti-86-95 hFSH-beta antisera did not show any detectable binding, proving the region 31-52 hFSH-beta to be a specific antigenic determinant of hFSH. The bioneutralizing abilities of the anti-peptide antibodies were assessed by measuring the hFSH-induced progesterone secretion by rat granulosa cells in vitro. Antibodies to 31-52 and 66-75 hFSH-beta neutralized the bioactivity of hFSH, but anti-86-95 hFSH-beta antibodies did not. Furthermore, the three linear peptides and two disulphide looped peptides of 31-52 hFSH-beta and 86-95 hFSH-beta were also subjected to the in-vitro granulosa cell assay. The linear peptides 31-52 hFSH-beta and 66-75 hFSH-beta and the cyclic 31-52 hFSH-beta disulphide loop peptide significantly inhibited the hFSH-induced progesterone secretion by rat granulosa cells, but the linear 86-95 hFSH-beta peptide and the corresponding cyclic disulphide loop peptide did not. The results clearly show that the regions 31-52 and 66-75 of hFSH-beta harbor bioneutralization epitopes of the hormone. The studies also indicate that cyclization of the linear 31-52 hFSH-beta peptide greatly enhances receptor recognition and that the region 66-75 hFSH-beta may also be involved in hormone-receptor interaction.
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Affiliation(s)
- D Lal
- Institute for Research in Reproduction, Indian Council of Medical Research, Bombay, India
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