1
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Biondi B, Formaggio F, Toniolo C, Peggion C, Crisma M. Isolated α-turns in peptides: a selected literature survey. J Pept Sci 2023:e3476. [PMID: 36603599 DOI: 10.1002/psc.3476] [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: 10/28/2022] [Revised: 12/21/2022] [Accepted: 12/26/2022] [Indexed: 01/07/2023]
Abstract
The results of classifying into various types the 68 examples of isolated α-turns in the X-ray diffraction crystal structures of peptides documented in the literature are presented and discussed in this review article. α-Turns characterized by the trans disposition of all ω torsion angles are common for the backbone linear peptides investigated. In contrast, the cis arrangement of the N-terminal (ωi + 1 ) torsion angle, among those generated by the three residues internal to the α-turn, is a peculiar feature of 65% of the cyclic peptides. Among linear and cyclic peptides featuring the all-trans disposition of the ω torsion angles, only one third of the α-turns display φ,ψ values not too far from those characterizing regular α-helices. In general, our findings, taken together, suggest that a significant conformational diversity is compatible with the formation of an intramolecularly H-bonded C13 -member pseudocycle (α-turn) in linear and cyclic peptides.
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Affiliation(s)
- Barbara Biondi
- CNR-Institute of Biomolecular Chemistry, Padova Unit, Padua, Italy
| | - Fernando Formaggio
- CNR-Institute of Biomolecular Chemistry, Padova Unit, Padua, Italy.,Department of Chemical Sciences, University of Padova, Padua, Italy
| | - Claudio Toniolo
- CNR-Institute of Biomolecular Chemistry, Padova Unit, Padua, Italy.,Department of Chemical Sciences, University of Padova, Padua, Italy
| | - Cristina Peggion
- CNR-Institute of Biomolecular Chemistry, Padova Unit, Padua, Italy.,Department of Chemical Sciences, University of Padova, Padua, Italy
| | - Marco Crisma
- CNR-Institute of Biomolecular Chemistry, Padova Unit, Padua, Italy
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2
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Yao G, Kosol S, Wenz MT, Irran E, Keller BG, Trapp O, Süssmuth RD. The occurrence of ansamers in the synthesis of cyclic peptides. Nat Commun 2022; 13:6488. [PMID: 36310176 PMCID: PMC9618573 DOI: 10.1038/s41467-022-34125-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2022] [Accepted: 10/14/2022] [Indexed: 12/25/2022] Open
Abstract
α-Amanitin is a bicyclic octapeptide composed of a macrolactam with a tryptathionine cross-link forming a handle. Previously, the occurrence of isomers of amanitin, termed atropisomers has been postulated. Although the total synthesis of α-amanitin has been accomplished this aspect still remains unsolved. We perform the synthesis of amanitin analogs, accompanied by in-depth spectroscopic, crystallographic and molecular dynamics studies. The data unambiguously confirms the synthesis of two amatoxin-type isomers, for which we propose the term ansamers. The natural structure of the P-ansamer can be ansa-selectively synthesized using an optimized synthetic strategy. We believe that the here described terminology does also have implications for many other peptide structures, e.g. norbornapeptides, lasso peptides, tryptorubins and others, and helps to unambiguously describe conformational isomerism of cyclic peptides.
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Affiliation(s)
- Guiyang Yao
- grid.6734.60000 0001 2292 8254Institut für Chemie, Technische Universität Berlin, Strasse des 17. Juni 124, 10623 Berlin, Germany ,grid.8547.e0000 0001 0125 2443Center for Innovative Drug Discovery, Greater Bay Area Institute of Precision Medicine (Guangzhou), School of Life Sciences, Fudan University, Shanghai, PR China
| | - Simone Kosol
- grid.6734.60000 0001 2292 8254Institut für Chemie, Technische Universität Berlin, Strasse des 17. Juni 124, 10623 Berlin, Germany
| | - Marius T. Wenz
- grid.14095.390000 0000 9116 4836Department of Biology, Chemistry, Pharmacy, Freie Universität Berlin, Arnimallee 22, 14195 Berlin, Germany
| | - Elisabeth Irran
- grid.6734.60000 0001 2292 8254Institut für Chemie, Technische Universität Berlin, Strasse des 17. Juni 124, 10623 Berlin, Germany
| | - Bettina G. Keller
- grid.14095.390000 0000 9116 4836Department of Biology, Chemistry, Pharmacy, Freie Universität Berlin, Arnimallee 22, 14195 Berlin, Germany
| | - Oliver Trapp
- grid.5252.00000 0004 1936 973XDepartment of Chemistry and Pharmacy, Ludwig-Maximilians-University, Butenandtstr. 5-13, 81377 Munich, Germany ,grid.429508.20000 0004 0491 677XMax-Planck-Institute for Astronomy, Königstuhl 17, 69117 Heidelberg, Germany
| | - Roderich D. Süssmuth
- grid.6734.60000 0001 2292 8254Institut für Chemie, Technische Universität Berlin, Strasse des 17. Juni 124, 10623 Berlin, Germany
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3
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Yao G, Knittel CH, Kosol S, Wenz MT, Keller BG, Gruß H, Braun AC, Lutz C, Hechler T, Pahl A, Süssmuth RD. Iodine-Mediated Tryptathionine Formation Facilitates the Synthesis of Amanitins. J Am Chem Soc 2021; 143:14322-14331. [PMID: 34459587 DOI: 10.1021/jacs.1c06565] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Synthetic methods on the macrocyclization of peptides are of high interest since they facilitate the synthesis of various types of potentially bioactive compounds, e.g. addressing targets like protein-protein-interactions. Herein, we report on an efficient method to construct tryptathionine-cross-links in peptides between the amino acids Trp and Cys. This reaction not only is the basis for the total synthesis of the death cap toxin α-amanitin but also provides rapid access to various new amanitin analogues. This study for the first time presents a systematic compilation of structure-activity relations (SAR) of amatoxins with regard to RNA polymerase II inhibition and cytotoxicity with one amanitin derivative of superior RNAP II inhibition. The present approach paves the way for the synthesis of structurally diverse amatoxins as future payloads for antibody-toxin conjugates in cancer therapy.
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Affiliation(s)
- Guiyang Yao
- Institut für Chemie, Technische Universität Berlin, Strasse des 17. Juni 124, 10623 Berlin, Germany
| | - Caroline H Knittel
- Institut für Chemie, Technische Universität Berlin, Strasse des 17. Juni 124, 10623 Berlin, Germany
| | - Simone Kosol
- Institut für Chemie, Technische Universität Berlin, Strasse des 17. Juni 124, 10623 Berlin, Germany
| | - Marius T Wenz
- Department of Biology, Chemistry, Pharmacy, Freie Universität Berlin, Takustrasse 3, 14195 Berlin, Germany
| | - Bettina G Keller
- Department of Biology, Chemistry, Pharmacy, Freie Universität Berlin, Takustrasse 3, 14195 Berlin, Germany
| | - Hendrik Gruß
- Heidelberg Pharma Research GmbH, Gregor-Mendel-Straße 22, 68526 Ladenburg, Germany
| | - Alexandra C Braun
- Heidelberg Pharma Research GmbH, Gregor-Mendel-Straße 22, 68526 Ladenburg, Germany
| | - Christian Lutz
- Heidelberg Pharma Research GmbH, Gregor-Mendel-Straße 22, 68526 Ladenburg, Germany
| | - Torsten Hechler
- Heidelberg Pharma Research GmbH, Gregor-Mendel-Straße 22, 68526 Ladenburg, Germany
| | - Andreas Pahl
- Heidelberg Pharma Research GmbH, Gregor-Mendel-Straße 22, 68526 Ladenburg, Germany
| | - Roderich D Süssmuth
- Institut für Chemie, Technische Universität Berlin, Strasse des 17. Juni 124, 10623 Berlin, Germany
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4
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Matinkhoo K, Wong AAWL, Hambira CM, Kato B, Wei C, Müller C, Hechler T, Braun A, Gallo F, Pahl A, Perrin DM. Design, Synthesis, and Biochemical Evaluation of Alpha-Amanitin Derivatives Containing Analogs of the trans-Hydroxyproline Residue for Potential Use in Antibody-Drug Conjugates. Chemistry 2021; 27:10282-10292. [PMID: 34058032 DOI: 10.1002/chem.202101373] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2021] [Indexed: 01/08/2023]
Abstract
Alpha-amanitin, an extremely toxic bicyclic octapeptide extracted from the death-cap mushroom, Amanita phalloides, is a highly selective allosteric inhibitor of RNA polymerase II. Following on growing interest in using this toxin as a payload in antibody-drug conjugates, herein we report the synthesis and biochemical evaluation of several new derivatives of this toxin to probe the role of the trans-hydroxyproline (Hyp), which is known to be critical for toxicity. This structure activity relationship (SAR) study represents the first of its kind to use various Hyp-analogs to alter the conformational and H-bonding properties of Hyp in amanitin.
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Affiliation(s)
- Kaveh Matinkhoo
- Chemistry Department, University of British Columbia, 2036 Main Mall, Vancouver, British Columbia, V6T-1Z1, Canada
| | - Antonio A W L Wong
- Chemistry Department, University of British Columbia, 2036 Main Mall, Vancouver, British Columbia, V6T-1Z1, Canada
| | - Chido M Hambira
- Chemistry Department, University of British Columbia, 2036 Main Mall, Vancouver, British Columbia, V6T-1Z1, Canada
| | - Brandon Kato
- Chemistry Department, University of British Columbia, 2036 Main Mall, Vancouver, British Columbia, V6T-1Z1, Canada
| | - Charlie Wei
- Chemistry Department, University of British Columbia, 2036 Main Mall, Vancouver, British Columbia, V6T-1Z1, Canada
| | - Christoph Müller
- Heidelberg Pharma, Gregor-Mendel-Straße 22, 68526, Ladenburg, Germany
| | - Torsten Hechler
- Heidelberg Pharma, Gregor-Mendel-Straße 22, 68526, Ladenburg, Germany
| | - Alexandra Braun
- Heidelberg Pharma, Gregor-Mendel-Straße 22, 68526, Ladenburg, Germany
| | - Francesca Gallo
- Heidelberg Pharma, Gregor-Mendel-Straße 22, 68526, Ladenburg, Germany
| | - Andreas Pahl
- Heidelberg Pharma, Gregor-Mendel-Straße 22, 68526, Ladenburg, Germany
| | - David M Perrin
- Chemistry Department, University of British Columbia, 2036 Main Mall, Vancouver, British Columbia, V6T-1Z1, Canada
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5
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Hambira CM, Matinkhoo K, Pryyma A, Patrick BO, Perrin DM. Scaling Amatoxin Synthesis with an Improved Route to (2 S,3 R,4 R)-Dihydroxyisoleucine Exemplified by a Toxic, Clickable α-Amanitin Analogue. J Org Chem 2021; 86:5362-5370. [PMID: 33710901 DOI: 10.1021/acs.joc.0c03022] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Here we report a scalable synthesis of the key amino acid residue, (2S,3R,4R)-4,5-dihydroxyisoleucine (DHIle) in α-amanitin, that in turn enables the scalable synthesis of an equipotent analogue, Asn(N-ethylazide)-S,6'-dideoxy-α-amanitin, suitable for CuAAC conjugation to empower studies on therapeutic antibody-drug conjugates.
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Affiliation(s)
- Chido M Hambira
- Chemistry Department, The University of British Columbia, 2036 Main Mall, Vancouver, BC V6T1Z1, Canada
| | - Kaveh Matinkhoo
- Chemistry Department, The University of British Columbia, 2036 Main Mall, Vancouver, BC V6T1Z1, Canada
| | - Alla Pryyma
- Chemistry Department, The University of British Columbia, 2036 Main Mall, Vancouver, BC V6T1Z1, Canada
| | - Brian O Patrick
- Chemistry Department, The University of British Columbia, 2036 Main Mall, Vancouver, BC V6T1Z1, Canada
| | - David M Perrin
- Chemistry Department, The University of British Columbia, 2036 Main Mall, Vancouver, BC V6T1Z1, Canada
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6
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Pryyma A, Matinkhoo K, Wong AAWL, Perrin DM. Meeting key synthetic challenges in amanitin synthesis with a new cytotoxic analog: 5'-hydroxy-6'-deoxy-amanitin. Chem Sci 2020; 11:11927-11935. [PMID: 34094418 PMCID: PMC8162882 DOI: 10.1039/d0sc04150e] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2020] [Accepted: 10/02/2020] [Indexed: 12/18/2022] Open
Abstract
Appreciating the need to access synthetic analogs of amanitin, here we report the synthesis of 5'-hydroxy-6'-deoxy-amanitin, a novel, rationally-designed bioactive analog and constitutional isomer of α-amanitin, that is anticipated to be used as a payload for antibody drug conjugates. In completing this synthesis, we meet the challenge of diastereoselective sulfoxidation by presenting two high-yielding and diastereoselective sulfoxidation approaches to afford the more toxic (R)-sulfoxide.
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Affiliation(s)
- Alla Pryyma
- Department of Chemistry, University of British Columbia 2036 Main Mall Vancouver B.C. V6T 1Z1 Canada
| | - Kaveh Matinkhoo
- Department of Chemistry, University of British Columbia 2036 Main Mall Vancouver B.C. V6T 1Z1 Canada
| | - Antonio A W L Wong
- Department of Chemistry, University of British Columbia 2036 Main Mall Vancouver B.C. V6T 1Z1 Canada
| | - David M Perrin
- Department of Chemistry, University of British Columbia 2036 Main Mall Vancouver B.C. V6T 1Z1 Canada
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7
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Pahl A, Lutz C, Hechler T. Amatoxins as RNA Polymerase II Inhibiting Antibody–Drug Conjugate (ADC) Payloads. CYTOTOXIC PAYLOADS FOR ANTIBODY – DRUG CONJUGATES 2019. [DOI: 10.1039/9781788012898-00398] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Amatoxins are a group of natural toxins which occur in the death cap mushroom (Amanita phalloides). They work by inhibiting RNA polymerase II, which results in apoptosis. RNA-polymerase II inhibition is a novel mechanism of action in cancer therapy and offers the possibility of breaking through drug resistance or destroying dormant tumour cells, which could produce major clinical advances. Amanitin, as the most potent member of this toxin family, has been made accessible for cancer therapy by developing it as a payload for antibody–drug conjugates (ADCs). This chapter describes the discovery and chemistry of the amatoxins, and the development of the amanitin-ADC technology.
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Affiliation(s)
- Andreas Pahl
- Heidelberg Pharma Schriesheimer Str. 101 68526 Ladenburg Germany
| | - Christian Lutz
- Heidelberg Pharma Schriesheimer Str. 101 68526 Ladenburg Germany
| | - Torsten Hechler
- Heidelberg Pharma Schriesheimer Str. 101 68526 Ladenburg Germany
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8
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Blanc A, Dietrich DJ, Perrin DM. Solid-phase synthesis of amanitin derivatives and preliminary evaluation of cellular uptake and toxicity. Pept Sci (Hoboken) 2018. [DOI: 10.1002/pep2.24050] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Affiliation(s)
- Antoine Blanc
- Department of Chemistry; University of British Columbia; Vancouver V6T 1Z1 Canada
| | - David J. Dietrich
- Department of Chemistry; University of British Columbia; Vancouver V6T 1Z1 Canada
| | - David M. Perrin
- Department of Chemistry; University of British Columbia; Vancouver V6T 1Z1 Canada
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9
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May J, Fournier P, Patrick B, Perrin D. Synthesis, Characterisation, and In Vitro Evaluation of Pro2-Ile3-S-Deoxo-Amaninamide and Pro2-D-allo-Ile3-S-Deoxo-Amaninamide: Implications for Structure–Activity Relationships in Amanitin Conformation and Toxicity. Chemistry 2008; 14:3410-7. [DOI: 10.1002/chem.200701297] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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10
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Li C, Oberlies NH. The most widely recognized mushroom: chemistry of the genus Amanita. Life Sci 2005; 78:532-8. [PMID: 16203016 DOI: 10.1016/j.lfs.2005.09.003] [Citation(s) in RCA: 53] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2005] [Indexed: 11/24/2022]
Abstract
Many review papers have been published on mushrooms of the genus Amanita, as these are well known to both scientific and lay audiences, probably due to the toxic and/or hallucinogenic properties of some species. This article aims to supplement the content of previous reviews by categorizing all of the natural products isolated from any species in the genus Amanita. These compounds are subdivided into six major structural types, and references are provided for all species that have been examined chemically.
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Affiliation(s)
- Chen Li
- Natural Products Laboratory, Research Triangle Institute, P.O. Box 12194, 3040 Cornwallis Rd., Research Triangle Park, NC 27709-2194, USA
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11
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12
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Saviano M, Isernia C, Rossi F, Di Blasio B, Iacovino R, Mazzeo M, Pedone C, Benedetti E. Solid state structural analysis of the cyclooctapeptide cyclo- (Pro1-Pro-Phe-Phe-Ac6c-Ile-D-Ala-Val8). Biopolymers 2000; 53:189-99. [PMID: 10679623 DOI: 10.1002/(sici)1097-0282(200002)53:2<189::aid-bip9>3.0.co;2-7] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
A solid state analysis of the cyclic octapeptide c(-Pro(1)-Pro-Phe-Phe-Ac(6)c-Ile-D-Ala-Val(8)-) (C8-CLA), containing the Pro-Pro-Phe-Phe sequence, followed by the bulky helicogenic C(alpha,alpha)-dialkylated 1-aminocyclohexane-1-carboxylic acid (Ac(6)c) residue and a D-Ala residue in position 7, has been carried out by x-ray diffraction. The crystals, grown from a DMSO solution, are monoclinic, space group P2(1) with a = 13.458(3) A, b = 19. 404(5) A, c = 21.508(4) A, and beta = 90.83(6) degrees, with two independent cyclic molecules in the asymmetric unit, two DMSO molecules, and three water molecules. The structure has been solved using the half and bake procedure by Sheldrick, and refined to final R1 and wR2 indices of 0.0613 and 0.1534 for 9867 reflections with I > 2sigma(I). This cyclic peptide, a deletion analogue of the naturally occurring cyclic nonapeptide cyclolinopeptide A [c(Pro-Pro-Phe-Phe-Leu-Ile-Ile-Leu-Val), CLA] has been designed to study the influence of the ring size reduction on the conformational behavior of CLA and more in general to obtain structural information on asymmetric cyclic octapeptides. The compound exhibits, in the solid state, a "banana-twisted" conformation with a cis peptide bond located between the two proline residues. Five intramolecular H bonds stabilize the structure: one type VIa beta-turn, two consecutive type III/I beta-turns, one gamma-turn, and one C(16) bend. The structure has also been compared with either the solution structure previously reported by us and obtained by nmr and computational analysis, and with solid state structural data reported in the literature on cyclic octapeptides.
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Affiliation(s)
- M Saviano
- Centro di Studio di Biocristallografia del CNR, Dipartimento di Chimica, Università di Napoli, via Mezzocannone 4,80134, Napoli, Italy
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13
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Isernia C, Falcigno L, Macura S, Paolillo L, Pastore AL, Zanotti G. Elucidation of the structure of constrained bicyclopeptides in solution by two-dimensional cross-relaxation spectroscopy: Amatoxin analogues. J Pept Sci 1998. [DOI: 10.1002/psc.44.o] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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14
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Abstract
The X-ray diffraction experiments on peptides and related molecules which have been carried out in Western Europe, except Italy, in the last eight years are reviewed. The crystal structures of some bioactive peptides such as Leu-enkephalin (a neurotransmitter), cyclosporin A (an immunomodulator in both the free and protein-bound state), balhimycin (an antibiotic) and octreotide (a somatostatin analogue) are briefly presented. Crystallized N- and C-protected model peptides have given an insight into the folding tendency and folding modes depending on the peptide sequences. The crystal structures of various pseudopeptide molecules reveal how the three-dimensional structure of peptide analogues can be modulated by substituting non-peptide groups for the peptide bond. A few examples of structural mimetics of the beta- and gamma-turns, and of templates for alpha-helix induction are also presented.
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Affiliation(s)
- M Marraud
- LCPM, CNRS-URA 494, ENSIC-INPL, Nancy, France
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15
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Isernia C, Falcigno L, Macura S, Paolillo L, Pastore AL, Zanotti G. Elucidation of the structure of constrained bicyclopeptides in solution by two-dimensional cross-relaxation spectroscopy: amatoxin analogues. J Pept Sci 1996; 2:3-13. [PMID: 9225241 DOI: 10.1002/psc.44] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
The evaluation of peptide structures in solution is made feasible by the combined use of two-dimensional NMR in the laboratory (NOESY) and rotating frames (ROESY), and by the use of molecular dynamics calculations. The present paper describes how both the NMR method and molecular dynamics calculations were applied to very rigid synthetic bicycle peptides that are analogues of natural amatoxins. The NMR theory, which allows the estimate of interatomic distances between interacting nuclei, is briefly discussed. The experimental data were compared with those of known solid-state structures. Three amatoxin analogues have been examined. Of these, one is biologically active (S-deoxo gamma[R] OH-Ile3-amaninamide) and its structure in the solid state has recently been worked out. The second and third analogues (S-dexo-Ile3-Ala5-amaninamide and S-deoxo-D-Ile3-amaninamide, respectively) are inactive and their solid-state structures are unknown. The data presented confirm the authors previous hypothesis that lack of biological activity of S-deoxo-Ile3-Ala5-amaninamide is due to the masking of the tryptophan ring by the methyl group of L-Ala and not to massive conformational changes of the analogue.
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Affiliation(s)
- C Isernia
- Second University of Naples, Environmental Sciences Faculty, Caserta, Italy
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16
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Baumann K, Münter K, Faulstich H. Identification of structural features involved in binding of alpha-amanitin to a monoclonal antibody. Biochemistry 1993; 32:4043-50. [PMID: 8471612 DOI: 10.1021/bi00066a027] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Twenty-four derivatives of the cyclic octapeptide alpha-amanitin were assayed for their affinities to the monoclonal antibody beta A1/1. The derivatives were of natural, semisynthetic, and synthetic origin and had KD values ranging from 2 nM to > 70 microM. In the majority of the derivatives the chemical modifications had no detectable influence on the overall shape of the double-ring peptide. Given this condition, binding factors could be calculated from KD values of the amatoxin derivatives, which were valid for all amatoxins for estimating the contribution made by single structures to complex formation. The complex between alpha-amanitin and the immunoglobulin involves at least eight sites of contact. Four of them are responsible for strong interactions: (1) the OH group of hydroxyproline2 (binding factor 413), (2) the lipophilic side chain of isoleucine6 (binding factor 131), (3) the -CH2- moiety of the adjacent glycine5 or the absence of a side chain in this position (binding factor 361), and (4) the proton at the indole nitrogen of hydroxytryptophan4 (binding factor 140). The residual four interactions are hydrogen bonds of lower strength corresponding to binding factors of 1.5-8. The key role of the unique conformation of the amatoxins in determining their binding properties was shown by two amatoxin derivatives in which changes in the conformation were associated with virtually complete loss of affinity. For all amatoxin derivatives with conformations similar or identical to that of alpha-amanitin, we found empirical evidence that those structures of the peptide involved in binding make their contributions virtually independent of each other. It is a consequence of this rule that structural features that cooperate in binding could be characterized by the numerical product of their binding factors.
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Affiliation(s)
- K Baumann
- Max-Planck-Institut für medizinische Forschung, Heidelberg, Germany
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17
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Lautz J, Kessler H, van Gunsteren WF, Weber HP, Wenger RM. On the dependence of molecular conformation on the type of solvent environment: a molecular dynamics study of cyclosporin A. Biopolymers 1990; 29:1669-87. [PMID: 2386812 DOI: 10.1002/bip.360291214] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
The dependence of the conformation of cyclosporin A (CPA), a cyclic undecapeptide with potent immunosuppressive activity, on the type of solvent environment is examined using the computer simulation method of molecular dynamics (MD). Conformational and dynamic properties of CPA in aqueous solution are obtained from MD simulations of a CPA molecule dissolved in a box with water molecules. Corresponding properties of CPA in apolar solution are obtained from MD simulations of CPA in a box with carbontetrachloride. The results of these simulations in H2O and in CCl4 are compared to each other and to those of previous simulations of crystalline CPA and of an isolated CPA molecule. The conformation of the backbone of the cyclic polypeptide is basically independent of the type of solvent. In aqueous solution the beta-pleated sheet is slightly weaker and the gamma-turn is a bit less pronounced than in apolar solution. Side chains may adopt different conformations in different solvents. In apolar solution the hydrophobic side chain of the MeBmt residue is in an extended conformation with its hydroxyl group hydrogen bonded to the backbone carbonyl group. In aqueous solution this hydrophobic side chain folds over the core of the molecule and the mentioned hydrogen bond is broken in favor of hydrogen bonding to water molecules. The conformation obtained from the MD simulation in CCl4 nicely agrees with experimental atom-atom distance data as obtained from nmr experiments in chloroform. In aqueous solution the relaxation of atomic motion tends to be slower than in apolar solution.
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Affiliation(s)
- J Lautz
- Department of Physical Chemistry, University of Groningen, The Netherlands
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18
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Zanotti G, Wieland T, D'Auria G, Paolillo L, Trivellone E. S-deoxo-Abu1,Ile3-amaninamide, an inactive amatoxin analogue. INTERNATIONAL JOURNAL OF PEPTIDE AND PROTEIN RESEARCH 1990; 35:263-70. [PMID: 2354877 DOI: 10.1111/j.1399-3011.1990.tb00947.x] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
The title compound 3, an amatoxin analogue containing L-alpha-aminobutyric acid instead of L-asparagine in position 1, as in natural toad stool peptides, has been synthesized. It does not inhibit the eukaryotic DNA-dependent RNA polymerase form II (or B) in concentrations up to 10(-4)M, whereas 50% inhibition is exerted in 10(-6)M solution by the corresponding Asn-analogue S-deoxo-Ile3-amaninamide 2. The striking difference seems to be due to a relatively small variation of the conformation recognized by sensitive NMR spectroscopic methods.
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Affiliation(s)
- G Zanotti
- CNR, Department of Pharmaceutical Sciences, University La Sapienza, Rome, Italy
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Zanotti G, Wieland T, Benedetti E, Di Blasio B, Pavone V, Pedone C. Structure-toxicity relationships in the amatoxin series. Synthesis of S-deoxy[gamma(R)-hydroxy-Ile3]-amaninamide, its crystal and molecular structure and inhibitory efficiency. INTERNATIONAL JOURNAL OF PEPTIDE AND PROTEIN RESEARCH 1989; 34:222-8. [PMID: 2599760 DOI: 10.1111/j.1399-3011.1989.tb00234.x] [Citation(s) in RCA: 24] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
The amatoxins, highly toxic components of Amanita mushrooms, strongly inhibit the DNA-dependent RNA polymerase II (or B) in eukaryotic cell nuclei. For optimal binding to the enzyme a gamma-hydroxyisoleucine side chain in the 3-position is important as in gamma-amanitin (compound 1), where the OH-group is bound in the [S]-configuration. Amanullin, a non-toxic component, having an oxygen-free isoleucine side chain no. 3, exhibits an inhibitory effect on RNA polymerase II about two orders of magnitude smaller than that of gamma-amanitin. An equal, relatively weak, inhibitory effect has previously been found with the synthetically obtained Ile3-analog 7. In the present paper the synthesis of an analog (2) bearing a gamma-hydroxyl group in the isoleucine side chain is described. The compound was found to have about the same inhibitory effect on RNA polymerase II from Drosophila embryos as amanullin and the Ile3-analog 7. Structure analysis by X-ray diffraction revealed that the hydroxyl group at the -carbon atom of side chain-3 has the [R]-configuration, the new analog thus being -deoxo[( )-hydroxy-[Ile3]-amaninamide. It follows that the [S]-configuration of this chiral center is a prerequisite to maximal toxicity. Crystallographic data demonstrating great similarity between the peptide backbones of the new analog and those of natural amatoxins are given.
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Affiliation(s)
- G Zanotti
- Department of Pharmaceutical Studies, University La Sapienza, Rome, Italy
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Chen PS, Stumm-Zollinger E, Aigaki T, Balmer J, Bienz M, Böhlen P. A male accessory gland peptide that regulates reproductive behavior of female D. melanogaster. Cell 1988; 54:291-8. [PMID: 3135120 DOI: 10.1016/0092-8674(88)90192-4] [Citation(s) in RCA: 444] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
The adult male accessory glands of D. melanogaster synthesize and secrete a peptide that represses female sexual receptivity and stimulates oviposition. Normally, this peptide is transferred to females during copulation; however, the peptide shows the same biological activity after purification and subsequent injection into the abdominal cavity of female virgins. Amino acid sequencing of the purified peptide and oligonucleotide-directed cDNA cloning established that the peptide consists of 36 amino acids. It appears to be synthesized as a precursor with a hydrophobic signal sequence of 19 residues at its N-terminal end. The precursor peptide is encoded by a short mRNA that accumulates exclusively in the male accessory gland. The gene has been localized by in situ hybridization to polytene chromosomes at 70A.
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Affiliation(s)
- P S Chen
- Institute of Zoology, University of Zürich, Switzerland
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Zanotti G, Möhringer C, Wieland T. Synthesis of analogues of amaninamide, an amatoxin from the white Amanita virosa mushroom. INTERNATIONAL JOURNAL OF PEPTIDE AND PROTEIN RESEARCH 1987; 30:450-9. [PMID: 3429128 DOI: 10.1111/j.1399-3011.1987.tb03353.x] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Analogs of amaninamide, due to the absence of a 6-hydroxy group in the tryptophan moiety, are more easily accessible by synthesis than derivatives of alpha-amanitin. Syntheses of bicyclic octapeptide thioethers 1f-1m have been carried out starting from linear Hpi-S-trityl-octapeptides (3), cyclization by intramolecular 2'-indolylthioether formation yielding monocyclic peptides (2) and final cyclization by DCCI. One of the bicyclic thioethers was oxidized to yield the corresponding chromatographically separated (R)- and (S)-sulfoxides, respectively. The products were characterized by RF-values, u.v. and CD spectra as well as by mass (FAB) spectroscopy. The widely differing inhibitory activities on RNA polymerase II (or B) from calf thymus are listed.
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Affiliation(s)
- G Zanotti
- C.N.R. Institute of Pharmaceutical Chemistry, University La Sapienza, Rome, Italy
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Zanotti G, D'Auria G, Paolillo L, Trivellone E. Synthetic amatoxin analogue. A two-dimensional proton NMR study of S-deoxy-(Ile3)-(D-Ala7)-amaninamide. BIOCHIMICA ET BIOPHYSICA ACTA 1986; 870:454-62. [PMID: 3697361 DOI: 10.1016/0167-4838(86)90253-0] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
The effect of substitution of L and D amino acids in amatoxin analogues is discussed in this paper. The structure of the analog where D-alanine substitutes for glycine in position 7 has been worked out in solution by two-dimensional NMR methods using a 500 MHz instrument. The combined use of COSY and NOESY two-dimensional spectra allows a clear assignment of the resonances. The use of the coupling constants permits the calculation of the phi angles of the backbone. The NOE effects reveal the through-space contacts between protons of different peptide units, thus determining the rigidity of the amatoxin structure. On these grounds it has been possible to elucidate the conformation of the amatoxin analogue that resembles very closely that of beta-amanitin, thus explaining the high inhibitory activity toward RNA polymerase B.
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Loosli HR, Kessler H, Oschkinat H, Weber HP, Petcher TJ, Widmer A. Peptide conformations. Part 31. The conformation of cyclosporin a in the crystal and in solution. Helv Chim Acta 1985. [DOI: 10.1002/hlca.19850680319] [Citation(s) in RCA: 292] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Benedetti E. X-ray crystallography of peptides: the contributions of the Italian laboratories. Biopolymers 1996; 40:3-44. [PMID: 8541447 DOI: 10.1002/(sici)1097-0282(1996)40:1<3::aid-bip2>3.0.co;2-#] [Citation(s) in RCA: 131] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
The review article summarizes the most relevant solid state structural and conformational results obtained in the laboratories involved in Italy in the studies of synthetic and natural peptides by x-ray diffraction analyses. Some of the topics will include research studies carried out in other European countries, whereas in other cases studies carried out in Italy will be included in other review articles included in this volume. The review deals with peptides containing symmetrically achiral and unsymmetrically chiral C alpha,alpha-dialkylated glycine residues, peptides containing beta-alanine residues, alpha,beta-dehydroamino acid residues, and aminosuccinyl residues, peptides containing the thioamide surrogate, heterochiral peptides and several bioactive peptides systems with the proposed relationships between function and structure.
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Affiliation(s)
- E Benedetti
- Biocrystallography Centre, CNR, University of Napoli Federico II, Italy
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