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Apostolopoulos V, Bojarska J, Chai TT, Elnagdy S, Kaczmarek K, Matsoukas J, New R, Parang K, Lopez OP, Parhiz H, Perera CO, Pickholz M, Remko M, Saviano M, Skwarczynski M, Tang Y, Wolf WM, Yoshiya T, Zabrocki J, Zielenkiewicz P, AlKhazindar M, Barriga V, Kelaidonis K, Sarasia EM, Toth I. A Global Review on Short Peptides: Frontiers and Perspectives. Molecules 2021; 26:E430. [PMID: 33467522 PMCID: PMC7830668 DOI: 10.3390/molecules26020430] [Citation(s) in RCA: 168] [Impact Index Per Article: 56.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2020] [Revised: 12/23/2020] [Accepted: 01/09/2021] [Indexed: 12/13/2022] Open
Abstract
Peptides are fragments of proteins that carry out biological functions. They act as signaling entities via all domains of life and interfere with protein-protein interactions, which are indispensable in bio-processes. Short peptides include fundamental molecular information for a prelude to the symphony of life. They have aroused considerable interest due to their unique features and great promise in innovative bio-therapies. This work focusing on the current state-of-the-art short peptide-based therapeutical developments is the first global review written by researchers from all continents, as a celebration of 100 years of peptide therapeutics since the commencement of insulin therapy in the 1920s. Peptide "drugs" initially played only the role of hormone analogs to balance disorders. Nowadays, they achieve numerous biomedical tasks, can cross membranes, or reach intracellular targets. The role of peptides in bio-processes can hardly be mimicked by other chemical substances. The article is divided into independent sections, which are related to either the progress in short peptide-based theranostics or the problems posing challenge to bio-medicine. In particular, the SWOT analysis of short peptides, their relevance in therapies of diverse diseases, improvements in (bio)synthesis platforms, advanced nano-supramolecular technologies, aptamers, altered peptide ligands and in silico methodologies to overcome peptide limitations, modern smart bio-functional materials, vaccines, and drug/gene-targeted delivery systems are discussed.
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Affiliation(s)
- Vasso Apostolopoulos
- Institute for Health and Sport, Victoria University, Melbourne, VIC 3030, Australia; (V.A.); (J.M.); (V.B.)
| | - Joanna Bojarska
- Institute of General and Ecological Chemistry, Faculty of Chemistry, Lodz University of Technology, Żeromskiego 116, 90-924 Lodz, Poland
| | - Tsun-Thai Chai
- Department of Chemical Science, Faculty of Science, Universiti Tunku Abdul Rahman, Kampar 31900, Malaysia;
| | - Sherif Elnagdy
- Botany and Microbiology Department, Faculty of Science, Cairo University, Gamaa St., Giza 12613, Egypt; (S.E.); (M.A.)
| | - Krzysztof Kaczmarek
- Institute of Organic Chemistry, Faculty of Chemistry, Lodz University of Technology, Żeromskiego 116, 90-924 Lodz, Poland; (K.K.); (J.Z.)
| | - John Matsoukas
- Institute for Health and Sport, Victoria University, Melbourne, VIC 3030, Australia; (V.A.); (J.M.); (V.B.)
- NewDrug, Patras Science Park, 26500 Patras, Greece;
- Department of Physiology and Pharmacology, Cumming School of Medicine, University of Calgary, Calgary, AB T2N 4N1, Canada
| | - Roger New
- Vaxcine (UK) Ltd., c/o London Bioscience Innovation Centre, London NW1 0NH, UK;
- Faculty of Science & Technology, Middlesex University, The Burroughs, London NW4 4BT, UK;
| | - Keykavous Parang
- Center for Targeted Drug Delivery, Department of Biomedical and Pharmaceutical Sciences, Chapman University School of Pharmacy, Harry and Diane Rinker Health Science Campus, Irvine, CA 92618, USA;
| | - Octavio Paredes Lopez
- Centro de Investigación y de Estudios Avanzados del IPN, Departamento de Biotecnología y Bioquímica, Irapuato 36824, Guanajuato, Mexico;
| | - Hamideh Parhiz
- Infectious Disease Division, Department of Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104-6073, USA;
| | - Conrad O. Perera
- School of Chemical Sciences, The University of Auckland, Private Bag 92019, Auckland 1142, New Zealand;
| | - Monica Pickholz
- Departamento de Física, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Buenos Aires 1428, Argentina;
- Instituto de Física de Buenos Aires (IFIBA, UBA-CONICET), Argentina, Buenos Aires 1428, Argentina
| | - Milan Remko
- Remedika, Luzna 9, 85104 Bratislava, Slovakia;
| | - Michele Saviano
- Institute of Crystallography (CNR), Via Amendola 122/o, 70126 Bari, Italy;
| | - Mariusz Skwarczynski
- School of Chemistry & Molecular Biosciences, The University of Queensland, St Lucia, QLD 4072, Australia; (M.S.); (I.T.)
| | - Yefeng Tang
- Key Laboratory of Bioorganic Phosphorus Chemistry & Chemical Biology (MOE), School of Pharma Ceutical Sciences, Tsinghua University, Beijing 100084, China;
| | - Wojciech M. Wolf
- Institute of General and Ecological Chemistry, Faculty of Chemistry, Lodz University of Technology, Żeromskiego 116, 90-924 Lodz, Poland
| | | | - Janusz Zabrocki
- Institute of Organic Chemistry, Faculty of Chemistry, Lodz University of Technology, Żeromskiego 116, 90-924 Lodz, Poland; (K.K.); (J.Z.)
| | - Piotr Zielenkiewicz
- Institute of Biochemistry and Biophysics, Polish Academy of Sciences, Pawinskiego 5a, 02-106 Warsaw, Poland;
- Department of Systems Biology, Institute of Experimental Plant Biology and Biotechnology, University of Warsaw, Miecznikowa 1, 02-096 Warsaw, Poland
| | - Maha AlKhazindar
- Botany and Microbiology Department, Faculty of Science, Cairo University, Gamaa St., Giza 12613, Egypt; (S.E.); (M.A.)
| | - Vanessa Barriga
- Institute for Health and Sport, Victoria University, Melbourne, VIC 3030, Australia; (V.A.); (J.M.); (V.B.)
| | | | | | - Istvan Toth
- School of Chemistry & Molecular Biosciences, The University of Queensland, St Lucia, QLD 4072, Australia; (M.S.); (I.T.)
- Institute for Molecular Bioscience, The University of Queensland, St Lucia, QLD 4072, Australia
- School of Pharmacy, The University of Queensland, Woolloongabba, QLD 4102, Australia
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Vasudev PG, Aravinda S, Shamala N. Crystal structure of a tripeptide containing aminocyclododecane carboxylic acid: a supramolecular twisted parallel β-sheet in crystals. J Pept Sci 2016; 22:166-73. [PMID: 26856690 DOI: 10.1002/psc.2854] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2015] [Revised: 12/03/2015] [Accepted: 12/17/2015] [Indexed: 12/25/2022]
Abstract
The crystal structure of a tripeptide Boc-Leu-Val-Ac12 c-OMe (1) is determined, which incorporates a bulky 1-aminocyclododecane-1-carboxylic acid (Ac12 c) side chain. The peptide adopts a semi-extended backbone conformation for Leu and Val residues, while the backbone torsion angles of the C(α,α) -dialkylated residue Ac12 c are in the helical region of the Ramachandran map. The molecular packing of 1 revealed a unique supramolecular twisted parallel β-sheet coiling into a helical architecture in crystals, with the bulky hydrophobic Ac12 c side chains projecting outward the helical column. This arrangement resembles the packing of peptide helices in crystal structures. Although short oligopeptides often assemble as parallel or anti-parallel β-sheet in crystals, twisted or helical β-sheet formation has been observed in a few examples of dipeptide crystal structures. Peptide 1 presents the first example of a tripeptide showing twisted β-sheet assembly in crystals.
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Affiliation(s)
- Prema G Vasudev
- Department of Physics, Indian Institute of Science, Bangalore, 560012, India
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3
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Maity P, König B. Enantio- and diastereoselective syntheses of cyclic Cα-tetrasubstituted α-amino acids and their use to induce stable conformations in short peptides. Biopolymers 2007; 90:8-27. [DOI: 10.1002/bip.20902] [Citation(s) in RCA: 65] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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Harini VV, Aravinda S, Rai R, Shamala N, Balaram P. Molecular Conformation and Packing of Peptide β Hairpins in the Solid State: Structures of Two Synthetic Octapeptides Containing 1-Aminocycloalkane-1-Carboxylic Acid Residues at thei+2 Position of the β Turn. Chemistry 2005; 11:3609-20. [PMID: 15812872 DOI: 10.1002/chem.200401124] [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: 11/07/2022]
Abstract
Peptide beta-hairpin formation is facilitated by centrally positioned D-Pro-Xxx segments. The synthetic peptides Boc-Leu-Phe-Val-D-Pro-Ac(6)c-Leu-Phe-Val-OMe (1) and Boc-Leu-Phe-Val-D-Pro-Ac(8)c-Leu-Phe-Val-OMe (2) were synthesized in order to explore the role of bulky 1-aminocycloalkane-1-carboxylic acid residues (Ac(n)c, where n is the number of carbon atoms in the ring), at the i+2 position of the nucleating beta turn in peptide beta hairpins. Peptides 1 and 2 crystallize in the monoclinic space group P2(1) with two molecules in the asymmetric unit. The crystal structures of 1 and 2 provide conformational parameters for four peptide hairpin molecules. In all cases, the central segments adopts a type II' beta-turn conformation, and three of the four possible cross-strand hydrogen bonds are observed. Fraying of the hairpins at the termini is accompanied by the observation of NHpi interaction between the Leu(1)NH group and Phe(7) aromatic group. Cross strand stabilizing interactions between the facing residues Phe(2) and Phe(7) are suggested by the observed orientation of aromatic rings. Anomalous far-UV CD spectra observed in solution suggest that close proximity of the Phe rings is maintained even in isolated molecules. In both peptides 1 and 2, the asymmetric unit consists of approximately orthogonal hairpins, precluding the formation of a planar beta-sheet arrangement in the solid state. Solvent molecules, one dioxane and one water in 1, three water molecules in 2, mediate peptide association. A comparison of molecular conformation and packing motifs in available beta-hairpin structures permits delineation of common features. The crystal structures of beta-hairpin peptides provide a means of visualizing different modes of beta-sheet packing, which may be relevant in developing models for aggregates of polypeptides implicated in disease situations.
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Rathore RS. Conformational investigations on analogs of inflammation response inducing chemotactic tripeptide fMLP. Biopolymers 2005; 80:651-64. [PMID: 15648091 DOI: 10.1002/bip.20231] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Conformations of three analogs of for-L-Met-L-Leu-L-Phe-OH (fMLP), which initiates inflammatory response by interaction with the formyl peptide receptor (FPR), have been investigated by the application of the X-ray crystallographic technique. The investigated analogs of fMLP peptides are as follows: for-L-Met-1-amino-1-cyclooctane-carbonyl(Ac8c)-L-Phe-OMe; for-L-Met-L-Leu-L-p-iodo-Phe-OH; and for-L-Met-di-n-propylglycyl(Dpg)-L-Phe-OMe. The peptide backbone in and is constrained at position of fMLP by the introduction of Calpha,alpha-disubstituted glycines. In peptide, Phe-OMe is substituted by p-iodo-Phe-OH. Crystal structures reveal an overall folded conformation adopted by and. The former is folded in the type II beta-turn, which is stabilized by an intramolecular 1<--4 (formyl) C==O...H--N (Phe) hydrogen bond, whereas the latter is folded in an open turn without any intramolecular hydrogen bond. On the other hand, peptide has an extended conformation, and two different molecules in a crystallographic asymmetric unit form an antiparallel beta-sheet-like structure. In and, residues Ac8c and Dpg adopt left-handed helical and fully extended (C5) conformations, respectively. The cyclooctane ring in Ac8c acquires a boat-chair conformation. Crystal packing of is characterized by the association of aliphatic-aromatic rings via a C--H...pi interaction. In the crystal of, contrary to the usual observations, peptides are interlinked via networks of head-to-tail hydrogen bond and pi...pi interactions, which are generally observed to be mutually exclusive. The structure-function mechanism of the ligand-receptor interaction is discussed.
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Toniolo C, Crisma M, Formaggio F, Peggion C. Control of peptide conformation by the Thorpe-Ingold effect (C alpha-tetrasubstitution). Biopolymers 2002; 60:396-419. [PMID: 12209474 DOI: 10.1002/1097-0282(2001)60:6<396::aid-bip10184>3.0.co;2-7] [Citation(s) in RCA: 576] [Impact Index Per Article: 26.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
The preferred conformations of peptides heavily based on the currently extensively exploited achiral and chiral alpha-amino acids with a quaternary alpha-carbon atom, as determined by conformational energy computations, crystal-state (x-ray diffraction) analyses, and solution ((1)H-NMR and spectroscopic) investigations, are reviewed. It is concluded that 3(10)/alpha-helical structures and the fully extended (C(5)) conformation are preferentially adopted by peptide sequences characterized by this family of amino acids, depending upon overall bulkiness and nature (e.g., whether acyclic or C(alpha) (i) <--> C(alpha) (i) cyclized) of their side chains. The intriguing relationship between alpha-carbon chirality and bend/helix handedness is also illustrated. gamma-Bends and semiextended conformations are rarely observed. Formation of beta-sheet structures is prevented.
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Affiliation(s)
- C Toniolo
- Department of Organic Chemistry, University of Padova, Institute of Biomolecular Chemistry, CNR, 35131 Padova, Italy.
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7
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Spisani S, Traniello S, Cavicchioni G, Formaggio F, Crisma M, Toniolo C. Probing structural requirements of fMLP receptor: on the size of the hydrophobic pocket corresponding to residue 2 of the tripeptide. J Pept Sci 2002; 8:56-65. [PMID: 11860029 DOI: 10.1002/psc.369] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
The conformationally constrained f-L-Met-Ac(n)c-L-Phe-OMe (n = 4,9-12) tripeptides, analogues of the chemoattractant f-L-Met-L-Leu-L-Phe-OH, were synthesized in solution by classical methods and fully characterized. These compounds and the published f-L-Met-Xxx-L-Phe-OMe (Xxx = Aib and Ac(n)c where n = 3, 5-8) analogues were compared to determine the combined effect of backbone preferred conformation and side-chain bulkiness at position 2 on the relation of 3D-structure to biological activity. A conformational study of all the analogues was performed in solution by FT-IR absorption and 1H-NMR techniques. In parallel, each peptide was tested for its ability to induce chemotaxis, superoxide anion production and lysozyme secretion from human neutrophils. The biological and conformational data are discussed in relation to the proposed model of the chemotactic receptor on neutrophils, in particular of the hydrophobic pocket accommodating residue 2 of the tripeptide.
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Affiliation(s)
- Susanna Spisani
- Department of Biochemistry and Molecular Biology, University of Ferrara, Italy
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8
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9
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Romanelli A, Garella I, Menchise V, Iacovino R, Saviano M, Montesarchio D, Didierjean C, Di Lello P, Rossi F, Benedetti E. Crystal-state conformation of Calpha,alpha-dialkylated peptides containing chiral beta-homo-residues. J Pept Sci 2001; 7:15-26. [PMID: 11245201 DOI: 10.1002/psc.278] [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: 11/06/2022]
Abstract
Secondary structure formation and stability are essential features in the knowledge of complex folding topology of biomolecules. To better understand the relationships between preferred conformations and functional properties of beta-homo-amino acids, the synthesis and conformational characterization by X-ray diffraction analysis of peptides containing conformationally constrained Calpha,alpha-dialkylated amino acid residues, such as alpha-aminoisobutyric acid or 1-aminocyclohexane-1-carboxylic acid and a single beta-homoamino acid, differently displaced along the peptide sequence have been carried out. The peptides investigated are: Boc-betaHLeu-(Ac6c)2-OMe, Boc-Ac6c-betaHLeu-(Ac6c)2-OMe and Boc-betaHVal-(Aib)5-OtBu, together with the C-protected beta-homo-residue HCl.H-betaHVal-OMe. The results indicate that the insertion of a betaH-residue at position 1 or 2 of peptides containing strong helix-inducing, bulky Calpha,alpha-disubstituted amino acid residues does not induce any specific conformational preferences. In the crystal state, most of the NH groups of beta-homo residues of tri- and tetrapeptides are not involved in intramolecular hydrogen bonds, thus failing to achieve helical structures similar to those of peptides exclusively constituted of Calpha,alpha-disubstituted amino acid residues. However, by repeating the structural motifs observed in the molecules investigated, a beta-pleated sheet secondary structure, and a new helical structure, named (14/15)-helix, were generated, corresponding to calculated minimum-energy conformations. Our findings, as well as literature data, strongly indicate that conformations of betaH-residues, with the micro torsion angle equal to -60 degrees, are very unlikely.
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Affiliation(s)
- A Romanelli
- Centro di Studio di Biocristallografia, C.N.R. and Dipartimento di Chimica, Università degli Studi di Napoli Federico II, Italy
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10
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Saviano M, Iacovino R, Benedetti E, Moretto V, Banzato A, Formaggio F, Crisma M, Toniolo C. Preferred conformation of peptides based on cycloaliphatic C(alpha,alpha)-disubstituted glycines: 1-amino-cycloundecane-1-carboxylic acid (Ac11c). J Pept Sci 2000; 6:571-83. [PMID: 11147716 DOI: 10.1002/1099-1387(200011)6:11<571::aid-psc290>3.0.co;2-r] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Two complete series of N-protected oligopeptide esters to the pentamer level from 1-amino-cycloundecane-1-carboxylic acid (Ac11c), an alpha-amino acid conformationally constrained through a medium-ring C(i)alpha<-->C(i)alpha cyclization, and either the L-Ala or Aib residue, along with the N-protected Ac11c monomer and homo-dimer alkylamides, have been synthesized by solution methods and fully characterized. The preferred conformation of these model peptides has been assessed in deuterochloroform solution by FT-IR absorption and 1H-NMR techniques. Furthermore, the molecular structures of one derivative (Z-Ac11c-OH) and two peptides (the tripeptide ester Z-Aib-Ac11c-Aib-OtBu and the pentapeptide ester Z-Ac11c-(Aib)2-Ac11c-Aib-OtBu) have been determined in the crystal state by X-ray diffraction. The experimental results support the view that beta-bends and 3(10)-helices are preferentially adopted by peptides rich in Ac11c, the second largest cycloaliphatic C(alpha,alpha)-disubstituted glycine known. This investigation has allowed the authors to approach the completion of a detailed conformational analysis of the whole 1-amino-cycloalkane-1-carboxylic acid (Ac(n)c, with n = 3-12) series, which represents the prerequisite for their recent proposal of the 'Ac(n)c scan' concept.
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Affiliation(s)
- M Saviano
- Biocrystallography Research Centre, CNR, Department of Chemistry, University of Naples Federico II, Napoli, Italy
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Saviano M, Iacovino R, Menchise V, Benedetti E, Bonora GM, Gatos M, Graci L, Formaggio F, Crisma M, Toniolo C. Conformational restriction through C alpha i <--> C alpha i cyclization: Ac12c, the largest cycloaliphatic C alpha,alpha- disubstituted glycine known. Biopolymers 2000; 53:200-12. [PMID: 10679624 DOI: 10.1002/(sici)1097-0282(200002)53:2<200::aid-bip10>3.0.co;2-l] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Two complete series of N-protected, monodispersed oligopeptide esters to the pentamer level from 1-aminocyclododecane-1-carboxylic acid (Ac(12)c), an alpha-amino acid conformationally constrained through C(alpha)(i) <--> C(alpha)(i) cyclization, and either L-Ala or Aib residues, along with the N-protected Ac(12)c homopeptide alkylamide series from monomer to trimer, have been synthesized by solution methods and fully characterized. The solution-preferred conformations of these peptides have been assessed by Fourier transform ir absorption and (1)H-nmr techniques. Moreover, the molecular structures of one derivative (Z-Ac(12)c-OH) and three peptides [the tripeptide ester Z-L-Ala-Ac(12)c-L-Ala-OMe, the tripeptide alkylamide Z-(Ac(12)c)(3)-NHiPr, and the tetrapeptide ester Z-(Aib)(2)-Ac(12)c-Aib-OtBu (Aib, alpha-aminoisobutyric acid)] have been determined in the crystal state by x-ray diffraction. The results obtained point to the conclusion that beta-bends and 3(10)-helices are preferentially adopted by peptides based on Ac(12)c, the largest cycloaliphatic C-disubstituted glycine known. A comparison with the structural tendencies extracted from published works on peptides from Aib, the prototype of C-disubstituted glycines, and the other extensively studied members of the class of 1-aminocycloalkane-1-carboxylic acids (Ac(n) c, with n = 3-9), is made and the implications for the use of the Ac(12)c residue in the Ac(n) c scan approach of conformationally restricted analogues of bioactive peptides are briefly discussed.
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Affiliation(s)
- M Saviano
- Biocrystallography Research Center, CNR, Department of Chemistry, University of Naples "Federico II," 80134 Napoli, Italy
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Vijayalakshmi S, Rao RB, Karle IL, Balaram P. Comparison of helix-stabilizing effects of alpha,alpha-dialkyl glycines with linear and cycloalkyl side chains. Biopolymers 2000; 53:84-98. [PMID: 10644953 DOI: 10.1002/(sici)1097-0282(200001)53:1<84::aid-bip8>3.0.co;2-w] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
The ability of alpha, alpha-di-n-alkyl glycines with linear and cyclic alkyl side chains to stabilize helical conformations has been compared using a model heptapeptide sequence. The conformations of five synthetic heptapeptides (Boc-Val-Ala-Leu-Xxx-Val-Ala-Leu-OMe, Xxx = Ac8c, Ac7c, Aib, Dpg, and Deg, where Ac8c = 1-aminocyclooctane-1-carboxylic acid, Ac7c = 1-aminocycloheptane-1-carboxylic acid, Aib = alpha-aminoisobutyric acid, Dpg = alpha,alpha-di-n-propyl glycine, Deg = alpha,alpha-di-n-ethyl glycine) have been investigated. In crystals, helical conformations have been demonstrated by x-ray crystallography for the peptides, R-Val-Ala-Leu-Dpg-Val-Ala-Leu-OMe, (R = Boc and acetyl). Solution conformations of the five peptides have been studied by 1H-nmr. In the apolar solvent CDCl3, all five peptides favor helical conformations in which the NH groups of residues 3-7 are shielded from the solvent. Successive NiH<-->Ni + 1H nuclear Overhauser effects over the length of the sequence support a major population of continuous helical conformations. Solvent titration experiments in mixtures of CDCl3/DMSO provide evidence for solvent-dependent conformational transitions that are more pronounced for the Deg and Dpg peptides. Solvent-dependent chemical shift variations and temperature coefficients in DMSO suggest that the conformational distributions in the Deg/Dpg peptides are distinctly different from the Aib/Acnc peptides in a strongly solvating medium. Nuclear Overhauser effects provide additional evidence for the population of extended backbone conformations in the Dpg peptide, while a significant residual population of helical conformations is still detectable in the isomeric Ac7c peptide in DMSO.
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Affiliation(s)
- S Vijayalakshmi
- Department of Chemistry, Banaras Hindu University, Varanasi, India
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Gatos M, Formaggio F, Crisma M, Valle G, Toniolo C, Bonora GM, Saviano M, Iacovino R, Menchise V, Galdiero S, Pedone C, Benedetti E. Conformational characterization of peptides rich in the cycloaliphatic Cα,α-disubstituted glycine 1-amino-cyclononane-1-carboxylic acid. J Pept Sci 1997. [DOI: 10.1002/(sici)1099-1387(199709)3:5<367::aid-psc116>3.0.co;2-v] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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15
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Gatos M, Formaggio F, Crisma M, Valle G, Toniolo C, Bonora GM, Saviano M, Iacovino R, Menchise V, Galdiero S, Pedone C, Benedetti E. Conformational characterization of peptides rich in the cycloaliphatic C alpha,alpha-disubstituted glycine 1-aminocyclononane-1-carboxylic acid. J Pept Sci 1997; 3:367-82. [PMID: 9391912 DOI: 10.1002/(sici)1099-1387(199709)3:5%3c367::aid-psc116%3e3.0.co;2-v] [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: 02/05/2023]
Abstract
A series of N- and C-protected, monodispersed homo-oligopeptides (to the pentamer level) from the cycloaliphatic C alpha,alpha-dialkylated glycine 1-aminocyclononane-1-carboxylic acid (Ac9c) and two Ala/Ac9c tripeptides have been synthesized by solution methods and fully characterized. The conformational preferences of all the model peptides were determined in deuterochloroform solution by FT-IR absorption and 1H-NMR. The molecular structures of the amino acid derivatives mCIAc-Ac9c-OH and Z-Ac9c-OtBu, the dipeptide pBrBz-(Ac9c)2-OtBu, the tetrapeptide Z-(Ac9c)4-OtBu, and the pentapeptide Z-(Ac9c)5-OtBu were determined in the crystal state by X-ray diffraction. Based on this information, the average geometry and the preferred conformation for the cyclononyl moiety of the Ac9c residue have been assessed. The backbone conformational data are strongly in favour of the conclusion that the Ac9c residue is a strong beta-turn and helix former. A comparison with the structural propensity of alpha-aminoisobutyric acid, the prototype of C alpha,alpha-dialkylated glycines, and the other extensively investigated members of the family of 1-aminocycloalkane-1-carboxylic acids (Acnc, with n = 3-8) is made and the implications for the use of the Ac9c residue in conformationally constrained analogues of bioactive peptides are briefly examined.
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Affiliation(s)
- M Gatos
- Biopolymer Research Centre, CNR, University of Padova, Italy
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Crisma M, Formaggio F, Valle G, Toniolo C, Saviano M, Iacovino R, Zaccaro L, Benedetti E. Experimental evidence at atomic resolution for intramolecular N(SINGLEBOND)H · · · π (phenyl) interactions in a family of amino acid derivatives. Biopolymers 1997. [DOI: 10.1002/(sici)1097-0282(199707)42:1<1::aid-bip1>3.0.co;2-s] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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Toniolo C, Crisma M, Formaggio F, Benedetti E, Santini A, Iacovino R, Saviano M, Di Blasio B, Pedone C, Kamphuis J. Preferred conformation of peptides rich in alicyclic Cα,α-disubstituted glycines. Biopolymers 1996. [DOI: 10.1002/(sici)1097-0282(1996)40:5<519::aid-bip9>3.0.co;2-z] [Citation(s) in RCA: 44] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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