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Marafon G, Menegazzo I, De Zotti M, Crisma M, Toniolo C, Moretto A. Tuning morphological architectures generated through living supramolecular assembly of a helical foldamer end-capped with two complementary nucleobases. SOFT MATTER 2017; 13:4231-4240. [PMID: 28509927 DOI: 10.1039/c7sm00764g] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Two appropriately functionalized nucleobases, thymine and adenine, have been covalently linked at the N- and C-termini, respectively, of two α-aminoisobutyric acid-rich helical peptide foldamers, aiming at driving self-assembly through complementary recognition. A crystal-state analysis (by X-ray diffraction) on the shorter, achiral foldamer 1 unambiguously shows that adeninethymine base pairing, through Watson-Crick intermolecular H-bonding, does take place between either end of each peptide molecule. In the crystals, π-stacking between base pairs is also observed. Evidence for time-dependent foldameroldamer associations for the longer, chiral foldamer 2 in solution is provided by circular dichroism measurements. The self-assembly of foldamer 2, through living supramolecular polymerization, eventually leads to the formation of twisted fibers. Such a supramolecular organization can be affected by addition of either pristine adenine or thymine, that acts as a "terminator" by selectively matching a pairing nucleobase at one end of the foldamer. The co-assembly of foldamer 2 with a porphyrin-derivatized thymine, under appropriate experimental conditions, leads to the formation of vesicles which, in turn, can be converted to the fiber morphology by changing the environmental polarity. Conversely, dendrimeric, star polymer-like microstructures are generated when the supramolecular assembly of foldamer 2 is seeded by adenine-capped gold nanoparticles.
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Affiliation(s)
- Giulia Marafon
- Department of Chemical Sciences, University of Padova, 35131 Padova, Italy.
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2
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Crisma M, De Zotti M, Formaggio F, Peggion C, Moretto A, Toniolo C. Handedness preference and switching of peptide helices. Part II: Helices based on noncodedα-amino acids. J Pept Sci 2015; 21:148-77. [DOI: 10.1002/psc.2743] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2014] [Revised: 12/19/2014] [Accepted: 12/19/2014] [Indexed: 12/27/2022]
Affiliation(s)
| | - Marta De Zotti
- Department of Chemistry; University of Padova; Padova Italy
| | - Fernando Formaggio
- ICB; Padova Unit; CNR Padova Italy
- Department of Chemistry; University of Padova; Padova Italy
| | | | - Alessandro Moretto
- ICB; Padova Unit; CNR Padova Italy
- Department of Chemistry; University of Padova; Padova Italy
| | - Claudio Toniolo
- ICB; Padova Unit; CNR Padova Italy
- Department of Chemistry; University of Padova; Padova Italy
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3
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Longo E, Moretto A, Formaggio F, Toniolo C. The critical main-chain length for helix formation in water: determined in a peptide series with alternating Aib and Ala residues exclusively and detected with ECD spectroscopy. Chirality 2012; 23:756-60. [PMID: 22135805 DOI: 10.1002/chir.20986] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
Critical main-chain length for peptide helix formation in the crystal (solid) state and in organic solvents has been already reported. In this short communication, we describe our results aiming at assessing the aforementioned parameter in water solution. To this goal, we synthesized step-by-step by solution procedures a complete series of N-terminally acetylated, C-terminally methoxylated oligopeptides, characterized only by alternating Aib and Ala residues, from the dimer to the nonamer level. All these compounds were investigated by electronic circular dichroism in the far-UV region in water solution as a function of chemical structure, namely presence/absence of an ester moiety or a negative charge at the C-terminus, and temperature. We find that the critical main-chain lengths for 3(10)- and α-helices, although still formed to a limited extent, in aqueous solution are six and eight residues, respectively.
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Affiliation(s)
- Edoardo Longo
- ICB, Padova Unit, CNR, Department of Chemistry, University of Padova, 35131 Padova, Italy
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4
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PATERSON YVONNE, STIMSON EVELYNR, EVANS DAVIDJ, LEACH SYDNEYJ, SCHERAGA HAROLDA. Solution conformations of oligomers of α -aminoisobutyric acid°. ACTA ACUST UNITED AC 2009. [DOI: 10.1111/j.1399-3011.1982.tb03069.x] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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5
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ALTMANN EVA, ALTMANN KARLHEINZ, NEBEL KURT, MUTTER MANFRED. Conformational studies on host-guest peptides containing chiral α-methyl-α-amino acids. ACTA ACUST UNITED AC 2009. [DOI: 10.1111/j.1399-3011.1988.tb01269.x] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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6
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Haynes SR, Hagins SD, Juban MM, Elzer PH, Hammer RP. Improved solid-phase synthesis of α,α-dialkylated amino acid-rich peptides with antimicrobial activity*. ACTA ACUST UNITED AC 2008; 66:333-47. [PMID: 16316449 DOI: 10.1111/j.1399-3011.2005.00312.x] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
A homologous series of nonapeptides and their acetylated versions were successfully prepared using solid-phase synthetic techniques. Each nonapeptide was rich in alpha,alpha-dialkylated amino acids [one 4-aminopiperidine-4-carboxylic acid (Api) and six alpha-aminoisobutyric acid (Aib) residues] and also included lysines or lysine analogs (two residues). The incorporation of the protected dipeptide 9-fluorenylmethyloxycarbonyl (Fmoc)-Aib-Aib-OH improved the purity and overall yields of these de novo designed peptides. The helix preference of each nonapeptide was investigated in six different solvent environments, and each peptide's antimicrobial activity and cytotoxicity were studied. The 3(10)-helical, amphipathic design of these peptides was born out most prominently in the N-terminally acetylated peptides. Most of the peptides exhibited modest activity against Escherichia coli and no activity against Staphylococcus aureus. The nonacetylated peptides (concentrations < or =100 microM) and the acetylated peptides (concentrations < or = 200 microM) did not exhibit any significant cytotoxicity with normal (nonactivated) murine macrophages.
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Affiliation(s)
- S R Haynes
- Department of Chemistry, Louisiana State University, Baton Rouge, LA 70803, USA
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7
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Leitgeb B, Szekeres A, Manczinger L, Vágvölgyi C, Kredics L. The history of alamethicin: a review of the most extensively studied peptaibol. Chem Biodivers 2007; 4:1027-51. [PMID: 17589875 DOI: 10.1002/cbdv.200790095] [Citation(s) in RCA: 180] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Affiliation(s)
- Balázs Leitgeb
- Institute of Biophysics, Biological Research Center of the Hungarian Academy of Sciences, Temesvári krt. 62, Szeged, Hungary
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8
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9
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Vogt H, Baumann T, Nieger M, Bräse S. Direct Asymmetric α-Sulfamidation of α-Branched Aldehydes: A Novel Approach to Enamine Catalysis. European J Org Chem 2006. [DOI: 10.1002/ejoc.200600587] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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10
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Zelezetsky I, Pag U, Sahl HG, Tossi A. Tuning the biological properties of amphipathic alpha-helical antimicrobial peptides: rational use of minimal amino acid substitutions. Peptides 2005; 26:2368-76. [PMID: 15939509 DOI: 10.1016/j.peptides.2005.05.002] [Citation(s) in RCA: 60] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/15/2005] [Revised: 04/29/2005] [Accepted: 05/02/2005] [Indexed: 11/23/2022]
Abstract
In nature, alpha-helical antimicrobial peptides present the small and flexible residue glycine at positions 7 or 14 with a significant frequency. Based on the sequence of the non-proteinogenic alpha-helical model peptide P1(Aib7), with a potent, broad spectrum antimicrobial activity, six peptides were designed by effecting a single amino acid substitution to investigate how tuning the structural characteristics at position 7 could lead to optimization of selectivity without affecting antimicrobial activity against a broad panel of multidrug resistant bacterial and yeast indicator strains. The relationship between structural features (size/hydrophobicity of the side chain as well as conformation and flexibility) and biological activity, in terms of minimum inhibitory concentration, membrane permeabilization kinetics and lysis of red blood cells are discussed. On conversion of the peptide to proteinogenic residues, these principles allowed development of a potent antimicrobial peptide with a reduced cytotoxicity. However, while results suggest that both hydrophobicity of residue 7 and chain flexibility at this position can be modulated to improve selectivity, position 14 is less tolerant of substitutions.
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Affiliation(s)
- Igor Zelezetsky
- Department of Biochemistry, Biophysics and Macromolecular Chemistry, University of Trieste, 34127 Trieste, Italy.
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11
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Jung G, Redemann T, Kroll K, Meder S, Hirsch A, Boheim G. Template-free self-assembling fullerene and lipopeptide conjugates of alamethicin form voltage-dependent ion channels of remarkable stability and activity. J Pept Sci 2004; 9:784-98. [PMID: 14658798 DOI: 10.1002/psc.525] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
N- and C-terminally modified with fullerene or lipopeptide alamethicin molecules were designed for the formation of template-free, self-assembling, voltage-dependent ion conducting channels. The automated solid phase synthesis of the alamethicin-F30 sequence was performed by in situ fluoride activation on 2-chlorotritylchloride-polystyrene resin and the conjugation with fullerenes-C60 and -C70 was carried out in solution. Voltage-dependent bilayer experiments revealed preferred channel sizes for C-terminal alamethicin F30-fullerene-C60 and -C70 conjugates and higher activity compared with native alamethicin, whereas N-terminally linked fullerene balls destabilize pore formation. C-terminal alamethicin F30-fullerene-C70 conjugates show pore states with remarkably long lifetimes of seconds. C-terminal lipopeptide conjugates of alamethicin were prepared by coupling via short peptide spacers with synthetic tripalmitoyl-S-glyceryl-cysteine. which represents the strong membrane anchoring N-terminus of bacterial lipoprotein. Alamethicin-lipopeptide conjugates exhibit high channel forming activities, whereby they self-assemble and adopt preferred pore states with extremely long lifetimes. The novel membrane modifying peptaibol constructs are valuable lead compounds for developments in sensorics related to transmembrane ion conductance.
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Affiliation(s)
- Günther Jung
- Institute of Organic Chemistry, University of Tübingen, Auf der Morgenstelle 18, 72076 Tübingen, Germany.
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Nguyen HH, Imhof D, Kronen M, Gräfe U, Reissmann S. Circular dichroism studies of ampullosporin-A analogues. J Pept Sci 2003; 9:714-28. [PMID: 14658791 DOI: 10.1002/psc.459] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Ampullosporin A (AmpA), a 15mer peptalbol containing seven Aib residues is able to induce pigmentation on Phoma destructiva and hypothermia in mice, as well as to exhibit a neuroleptic effect. A circular dichroism study of ampullosporin A and its analogues was carried out in organic solvents with different polarities and detergent micelles to determine the relationship between their conformational flexibility and biological activities. The analogues were obtained by modifying the N- and C-termini of ampullosporin A. Furthermore, Gln and Leu were systematically substituted by Ala and Aib residues were replaced by Ala and/or Ac6c. To estimate the helicity of the analogues, the CD spectrum of AmpA recorded in acetonitrile was correlated to its crystal structure. All analogues displayed similar CD curve shapes in organic solvents with the ratio between two negative band intensities R = [theta]n-pi*/[theta]pi-pi* < 1. In acetonitrile, most of the analogues adopted a 70%-85% helical structure, which was higher than the average of 40%-60% obtained in TFE. In detergent micelles, the analogues were distinguishable by their CD profiles. For most of the biologically active analogues, the CD spectra in detergent micelles were characterized by a R ratio > 1 and increased helicity compared with those recorded in TFE, suggesting that the interaction of the peptides with the membrane and peptide association was necessary for their hypothermic effect.
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Affiliation(s)
- Hoai-Huong Nguyen
- Institut für Biochemie und Biophysik, Friedrich-Schiller-Universität Jena, Philosophenweg 12, D-07743 Jena, Germany
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Silva RAGD, Yasui SC, Kubelka J, Formaggio F, Crisma M, Toniolo C, Keiderling TA. Discriminating 3(10)- from alpha-helices: vibrational and electronic CD and IR absorption study of related Aib-containing oligopeptides. Biopolymers 2002; 65:229-43. [PMID: 12382284 DOI: 10.1002/bip.10241] [Citation(s) in RCA: 75] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
Model peptides based on -(Aib-Ala)(n)-, and (Aib)(n)-Leu-(Aib)(2) sequences, which have varying amounts of 3(10)-helical character, were studied by use of vibrational and electronic circular dichroism (VCD and ECD) and Fourier transform infrared (FTIR) absorption spectroscopies to test the correlation of spectral response and conformation. The data indicate that these peptides, starting from a length of about four to six residues, predominantly adopt a 3(10)-helical conformation at room temperature. The longest model peptides, depending on the series, may evidence some alpha-helical contribution to the spectra, while the shorter ones, with less than six residues, have much less order. The IR absorption spectra (as supported by theory) showed only small frequency changes between 3(10)- and alpha-helices. By contrast, solvent effects are a source of much bigger perturbations. The ECD results show that the intensity ratio for the approximately 222-nm to approximately 208-nm bands, while useful for distinguishing between these two helical types in some sequences, may have a narrower range of application than VCD. However, the VCD data presented here continue to support the proposed discrimination between alpha- and 3(10)-helices based on qualitative amide I and II bandshape differences. The present study shows the intensities of the 3(10)-helical amide I (peak-to-peak) to its amide II VCD to be of the same order and useful for discriminating them from alpha-helices, whose amide I dominates the amide II in intensity. This qualitative result is experimentally independent of the amount of alphaMe-substituted residues in the sequence. These experimental VCD results are consistent in detail with theoretical spectral simulations for Ac-(Ala)(8)-NH(2), Ac-(Aib-Ala)(4)-NH(2), and Ac-(Aib)(8)-NH(2) in 3(10)- and alpha-helical conformations.
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Affiliation(s)
- R A Gangani D Silva
- Department of Chemistry (M/C 111), University of Illinois at Chicago, 845 W. Taylor Street, Chicago, IL 60607-7061, USA
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14
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Kaptein B, Broxterman QB, Schoemaker HE, Rutjes FP, Veerman JJ, Kamphuis J, Peggion C, Formaggio F, Toniolo C. Enantiopure Cα-tetrasubstituted α-amino acids. Chemo-enzymatic synthesis and application to turn-forming peptides. Tetrahedron 2001. [DOI: 10.1016/s0040-4020(01)00548-8] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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Peggion C, Flammengo R, Mossel E, Broxterman QB, Kaptein B, Kamphuis J, Formaggio F, Crisma M, Toniolo C. Mag: a Cα-Methylated, Side-chain Unsaturated α-Amino Acid. Introduction into Model Peptides and Conformational Preference. Tetrahedron 2000. [DOI: 10.1016/s0040-4020(00)00274-x] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/16/2022]
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16
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Péter A, Olajos E, Casimir R, Tourwé D, Broxterman QB, Kaptein B, Armstrong DW. High-performance liquid chromatographic separation of the enantiomers of unusual alpha-amino acid analogues. J Chromatogr A 2000; 871:105-13. [PMID: 10735291 DOI: 10.1016/s0021-9673(99)00889-4] [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: 11/26/2022]
Abstract
The direct and indirect stereochemical resolution of the enantiomers of ring- and alpha-methyl-substituted phenylalanines and phenylalanine amides was attempted by high-performance liquid chromatographic methods. The direct separation was carried out on two chiral stationary phases, the crown-ether-based Crownpak CR(+), and the teicoplanin-based Chirobiotic T, while the indirect resolution was performed by applying pre-column derivatization with 2,3,4,6-tetra-O-acetyl-beta-D-glucopyranosyl isothiocyanate (GITC) and Nalpha-(2,4-dinitro-5-fluorophenyl)-L-alanine amide (Marfey's reagent, FDAA). The Chirobiotic T column was efficient in the separation of ring- and alpha-methyl-substituted phenylalanine analogues, but was ineffective for the amides of these analogues. The Crownpak CR(+) column separated the ring-substituted phenylalanines and amides, whereas the alpha-methylated analogues were coeluted. Of the two indirect methods, GITC derivatization seemed more effective than FDAA derivatization.
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Affiliation(s)
- A Péter
- Department of Inorganic and Analytical Chemistry, Attila József University, Szeged, Hungary.
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Abstract
Human salivary histatin-5 (Hsn-5), a 24-amino acid polypeptide, is a potent candidacidal molecule. In this study, we have explored the following two hypotheses: More potent Hsn molecules may be achieved by duplication of the functional domain of Hsn-5 (C16, residues 9-24 of Hsn-5), and Hsn may act like other cationic peptides which aggregate and form channels across the target membrane. A PCR-based gene splicing by overlap extension (SOE) method was used to construct the DNA fragments encoding the following fusion molecules: Hsn-5--Hsn-5, Hsn-5--C16, and C16--C16. These constructs were expressed in E. coli, the proteins produced were purified, and their anticandidal activities as well as secondary structures were determined. Contrary to our hypotheses, results showed that none of the multimers possessed increased candidacidal activity. Specifically, C16--C16 and Hsn-5--C16 displayed candidacidal activity comparable with that of Hsn-5, while Hsn-5--Hsn-5 possessed significantly decreased candidacidal activity, yet all molecules retained an alpha-helical structure in a hydrophobic environment. Additionally, the circular dichroism data showed that Hsn-5 in an alpha-helical conformation does not aggregate in a hydrophobic environment, not even at 14- to 18-fold its physiological concentration. Our results suggest that the development of enhanced Hsn-5 molecules may not be achieved by duplication of its functional domain, and that Hsns may not act like other antimicrobial cationic peptides which aggregate and form channels across the target membrane.
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Affiliation(s)
- H Situ
- Department of Oral Biology, School of Dental Medicine, State University of New York at Buffalo, 14214, USA
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Obrecht D, Altorfer M, Bohdal U, Daly J, Huber W, Labhardt A, Lehmann C, Müller K, Ruffieux R, Schönholzer P, Spiegler C, Zumbrunn C. Design and synthesis of novel nonpolar host peptides for the determination of the 310- and α-helix compatibilities of α-amino acid buildig blocks: An assessment of α,α-disubstituted glycines. Biopolymers 1997. [DOI: 10.1002/(sici)1097-0282(19971015)42:5<575::aid-bip7>3.0.co;2-n] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
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19
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Gravert DJ, Janda KD. Organic Synthesis on Soluble Polymer Supports: Liquid-Phase Methodologies. Chem Rev 1997; 97:489-510. [PMID: 11848880 DOI: 10.1021/cr960064l] [Citation(s) in RCA: 507] [Impact Index Per Article: 18.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Dennis J. Gravert
- The Scripps Research Institute, Department of Chemistry and The Skaggs Institute for Chemical Biology, 10550 North Torrey Pines Road, La Jolla, California 92037
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Abstract
Human salivary histatins possess fungicidal and bactericidal activities. The current investigation evaluates the structure-function relationship of histatins with regard to their candidacidal activity by using recombinant histatin-5 and its variants produced in Escherichia coli. The purified recombinant histatins were examined for their candidacidal activity and secondary structure. The m21 (with Lys-13 replaced by Thr [Lys-13-->Thr]) and m71 (Lys-13-->Glu) variants are significantly less effective than recombinant histatin-5 in killing Candida albicans, suggesting that Lys-13 is critical for candidacidal activity. The m68 (Lys-13-->Glu and Arg-22-->Gly) variant is significantly less potent than the recombinant histatin-5 as well as m71, indicating that Arg-22 is crucial for the cidal activity. The candidacidal activities of m1 (Arg-12-->Ile), m2 (Arg-12-->Ile and Lys-17-->Asp), m12 (Arg-12-->Lys and His-21-->Leu), and m70 (His-19-->Pro and His-21-->Arg) variants, however, are comparable to that of recombinant histatin-5, indicating that Arg-12, Lys-17, His-19, and His-21 are not functionally important. The conformational preferences of histatin-5 and variants were determined by circular dichroism. The results indicate that all proteins have a strong tendency to adopt alpha-helical conformation in trifluoroethanol. Previously, we have shown that the alpha-helical conformation is one of the important structural requirements for eliciting appreciable candidacidal activity. Collectively, the data suggest that in addition to the helical conformation, specific residues such as Lys-13 and Arg-22 in the sequence of histatin-5 are, indeed, important for candidacidal activity.
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Affiliation(s)
- H Tsai
- Department of Oral Biology, School of Dental Medicine, State University of New York at Buffalo, 14214, USA
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Toniolo C, Polese A, Formaggio F, Crisma M, Kamphuis J. Circular Dichroism Spectrum of a Peptide 310-Helix. J Am Chem Soc 1996. [DOI: 10.1021/ja9537383] [Citation(s) in RCA: 326] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Claudio Toniolo
- Biopolymer Research Center, CNR Department of Organic Chemistry University of Padova, 35131 Padova, Italy DSM Research, Bio-organic Chemistry Section 6160 MD Geleen, The Netherlands
| | - Alessandra Polese
- Biopolymer Research Center, CNR Department of Organic Chemistry University of Padova, 35131 Padova, Italy DSM Research, Bio-organic Chemistry Section 6160 MD Geleen, The Netherlands
| | - Fernando Formaggio
- Biopolymer Research Center, CNR Department of Organic Chemistry University of Padova, 35131 Padova, Italy DSM Research, Bio-organic Chemistry Section 6160 MD Geleen, The Netherlands
| | - Marco Crisma
- Biopolymer Research Center, CNR Department of Organic Chemistry University of Padova, 35131 Padova, Italy DSM Research, Bio-organic Chemistry Section 6160 MD Geleen, The Netherlands
| | - Johan Kamphuis
- Biopolymer Research Center, CNR Department of Organic Chemistry University of Padova, 35131 Padova, Italy DSM Research, Bio-organic Chemistry Section 6160 MD Geleen, The Netherlands
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22
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Raj P, Soni S, Levine M. Membrane-induced helical conformation of an active candidacidal fragment of salivary histatins. J Biol Chem 1994. [DOI: 10.1016/s0021-9258(17)36925-9] [Citation(s) in RCA: 27] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
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23
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Otoda K, Kitagawa Y, Kimura S, Imanishi Y. Chain length dependent transition of 310- to ?-helix of Boc-(Ala-Aib)n-OMe. Biopolymers 1993. [DOI: 10.1002/bip.360330904] [Citation(s) in RCA: 77] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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24
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Salivary statherin. Dependence on sequence, charge, hydrogen bonding potency, and helical conformation for adsorption to hydroxyapatite and inhibition of mineralization. J Biol Chem 1992. [DOI: 10.1016/s0021-9258(18)42650-6] [Citation(s) in RCA: 187] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
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25
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Jung G, Beck-Sickinger AG, Dürr H, Gaida W, Schnorrenberg G. Alpha-helical small molecular size analogues of neuropeptide Y: structure-activity relationships. Biopolymers 1991; 31:613-9. [PMID: 1657233 DOI: 10.1002/bip.360310605] [Citation(s) in RCA: 25] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
C-terminal analogues of neuropeptide Y (NPY) of small molecular size have been synthesized. The influence of chain length, single or multiple amino acid substitution, and segment substitutions on receptor binding, pre- and postsynaptic biological activity, and conformational properties have been investigated. Receptor binding and in vivo assays revealed biological activity for NPY Ac-25-36 that increased with increasing alpha-helicity. In attempts to stabilize the alpha-helical content, three independent types of modified NPY Ac-25-36 analogues were synthesized. Strong agonistic activities could be detected in a series of discontinuous analogues, which are constructs of N-terminal parts linked via different spacer molecules to C-terminal segments. One of the most active molecules was NPY 1-4-Aca-25-36 (Aca, epsilon-aminocaproic acid). For the first time conformational properties of a series of small NPY analogues have been investigated by CD, and correlated with biological activity and receptor binding. A C-terminal dodecapeptide segment of NPY with an amount of 50% substitution to the native C-terminal sequence of NPY was found to exhibit significant receptor binding.
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Affiliation(s)
- G Jung
- Institut für Organische Chemie, Universität Tübingen, Germany
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26
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Manning MC, Woody RW. Theoretical CD studies of polypeptide helices: examination of important electronic and geometric factors. Biopolymers 1991; 31:569-86. [PMID: 1868170 DOI: 10.1002/bip.360310511] [Citation(s) in RCA: 281] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
An improved model for calculating the CD of polypeptides has been developed. Excited state wavefunctions were derived from CNDO/S (complete neglect of differential overlap, spectroscopic) calculations on N-methylacetamide. Four discrete peptide-localized transitions were employed: pi 0 pi* (NV1), pi* + pi* (NV2), n pi*, and n' pi*. Inclusion of the pi + pi transition (lambda 0 = 140 nm) significantly improves the accuracy of the calculated CD spectra in the 180-250-nm region. Spectra were computed for various helical structures, including right-handed alpha-, alpha II-, omega-, pi-, 3(10-), and poly (proline) I-helices, and the left-handed poly (proline) II-helix. Sensitivity to changes in the peptide backbone geometry and chain length are examined. Electronic factors such as ground-state charge distribution, hybridization effects, and basis set deorthogonalization have been investigated. The nonconservative nature of the poly (Pro) I and II CD spectra is reproduced, and the helix band present in earlier exciton calculations on the alpha-helix has been diminished.
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Affiliation(s)
- M C Manning
- Department of Biochemistry, Colorado State University, Fort Collins 80523
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Tian Z, Hrinyo-Pavlina T, Roeske RW, Rao P. Resolut of 2,3,4,6-tetra-O-acetyl-β-d-glucopyranosylisothiocyanate derivatives of α-methyl amino acid enantiomers by high-performance liquid chromatography. J Chromatogr A 1991. [DOI: 10.1016/s0021-9673(01)96001-7] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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Johnsen G, Elsayed S. Antigenic and allergenic determinants of ovalbumin--III. MHC Ia-binding peptide (OA 323-339) interacts with human and rabbit specific antibodies. Mol Immunol 1990; 27:821-7. [PMID: 1699119 DOI: 10.1016/0161-5890(90)90147-r] [Citation(s) in RCA: 43] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Three analogous peptides mimicking the known primary structure of ovalbumin (OA) in the region 323-339 (namely, OA 323-339, OA 323-338 and OA 324-336) were manually synthesized by the Merrifield solid phase technique. The synthetic preparations were purified by gel filtration and ion exchange high performance liquid chromatographies. The sequence linearities were deduced from the amino acid composition prior to each stage of coupling and the amino acid sequence determination on the ultimate chain. OA 323-339 was conjugated to BSA, using carbodiimide activation of the carrier protein and the conjugated compound was further used for production of antibodies in rabbit. The results showed that the region OA 323-339 was immunogenic; it could give immunoprecipitates with rabbit anti-OA 323-339-BSA in crossed immunoelectrophoresis (CIE). It similarly could bind human specific IgE from serum pools from patients allergic to egg in crossed radio immunoelectrophoresis (CRIE). Quantitative precipitation inhibition and specific IgE inhibition were used for confirming the antigenic and allergenic activities of this region. The results led us to conclude that the region 323-339 of the OA molecule encompassed an allergenic and antigenic epitope which were recognized by human and rabbit B-cells.
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Affiliation(s)
- G Johnsen
- Allergy Research Group, Laboratory of Clinical Biochemistry, University of Bergen, Norway
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29
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Raj PA, Edgerton M, Levine MJ. Salivary histatin 5: dependence of sequence, chain length, and helical conformation for candidacidal activity. J Biol Chem 1990. [DOI: 10.1016/s0021-9258(19)39678-4] [Citation(s) in RCA: 152] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
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30
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Leibfritz D, Brunne RM, Weihrauch T, Stelten J, Stohrer WD, Haupt ETK. NMR-Spectroscopic Assignment of the Aib-Methyl Groups in α-Helical and β-Turn Environment with the Use of Selectively Deuterated Aib The Solution Conformations of Boc-Ala-Aib-Ala-OMe. ACTA ACUST UNITED AC 1989. [DOI: 10.1002/jlac.198919890260] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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31
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Affiliation(s)
- S Buus
- Department of Medicine, National Jewish Center for Immunology & Respiratory Medicine, Denver, CO
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Cann JR, London RE, Unkefer CJ, Vavrek RJ, Stewart JM. CD-n.m.r. study of the solution conformation of bradykinin analogs containing alpha-aminoisobutyric acid. INTERNATIONAL JOURNAL OF PEPTIDE AND PROTEIN RESEARCH 1987; 29:486-96. [PMID: 3596900 DOI: 10.1111/j.1399-3011.1987.tb02275.x] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
The conformation in aqueous solution of several alpha-aminoisobutyric acid (AIB)-containing analogs of bradykinin (BK) has been probed by complementary CD and 1H n.m.r. measurements. The conclusion reached is that substitution of AIB for Pro2 and/or Pro3 in BK stabilizes a degree of beta-turn conformation in the N-terminal tetrapeptide moiety of the resulting analogs. Changing the solvent from water to DMSO or TFE further enhances the contribution of particular hydrogen bonded structures to the time-averaged conformation of these peptides. Bradykinin and [AIB7]-BK adopt similar hydrogen bonded conformations in TFE, apparently with a contribution from a beta-turn involving their common Arg1-Pro2-Pro3-Gly4 moiety. The contrasting biological activities of BK and its AIB-analogs are considered in terms of the conformational analogy between the AIB-residue and cis' Pro and the propensity for a beta-turn at the N-terminus of the peptide.
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33
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Valle G, Toniolo C, Jung G. Activated Amino Acids – Structures of [α-(Phthalimido)isobutyric] Anhydride, pentachlorophenyl α-(tert-Butyloxycarbonylamino)isobutanoate, and Pentachlorophenyl α-(Benzyloxycarbonylamino)isobutanoate. ACTA ACUST UNITED AC 1986. [DOI: 10.1002/jlac.198619861101] [Citation(s) in RCA: 8] [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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34
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Bosch R, Jung G, Schmitt H, Winter W. Crystal structure of Boc-Leu-Aib-Pro-Val-Aib-Aib-Glu(OBzl)-Gln-Phl × H2O, the C-terminal nonapeptide of the voltage-dependent ionophore alamethicin. Biopolymers 1985. [DOI: 10.1002/bip.360240606] [Citation(s) in RCA: 55] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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36
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Bode K, Goodman M, Mutter M. Conformational Studies on Potential ?-Turn-Forming Model Peptides. Helv Chim Acta 1985. [DOI: 10.1002/hlca.19850680320] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Schmitt H, Jung G. Total Synthesis of the α-Helical Eicosapeptide Antibiotic Alamethicin. ACTA ACUST UNITED AC 1985. [DOI: 10.1002/jlac.198519850210] [Citation(s) in RCA: 54] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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Brückner H, König WA, Aydin M, Jung G. Trichotoxin A40. Purification by counter-current distribution and sequencing of isolated fragments. BIOCHIMICA ET BIOPHYSICA ACTA 1985; 827:51-62. [PMID: 2578292 DOI: 10.1016/0167-4838(85)90100-1] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
The isolation of the membrane-modifying polypeptide antibiotics from the mycelium of Trichoderma viride 5242 was optimized via extraction with dichloromethane and chromatography on Sephadex LH-20. The components trichotoxin A40 and A50 were separated from each other and purified by multiplicative counter-current distribution. The sequence of proteinase-resistant trichotoxin A40 was determined by combined gas chromatography and mass spectrometry of three isolated N-acetylated dodecapeptides and two N-prolylhexapeptides obtained after selective trifluoroacetolysis. Including amino acid exchanges due to natural microheterogeneity, the sequence is Ac-Aib-Gly(LAla)-Aib-LLeu-Aib-LGln-Aib-Aib-Aib(LAla )-LAla-Aib-Aib-LPro-LLeu -Aib-DIva(Aib)-LGlu-LValol. In contrast to the eicosapeptide alamethicin, trichotoxin A40 contains only 18 residues, with a higher proportion of alpha-aminoisobutyric acid (Aib), C-terminal L-valinol (Vol), one D-isovaline (Iva) and no proline at the N-terminal part.
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39
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Bosch R, Jung G, Voges KP, Winter W. Conformation of Boc-L-Ala-Aib-L-Ala-OMe in the Crystal and in Solution. ACTA ACUST UNITED AC 1984. [DOI: 10.1002/jlac.198419840609] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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40
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Vijayakumar EKS, Sudha TS, Balaram P. Circular dichroism studies of ?-aminoisobutyric acid-containing peptides: Chain length and solvent effects in alternating Aib-L-Ala and Aib-L-Val sequences. Biopolymers 1984. [DOI: 10.1002/bip.360230505] [Citation(s) in RCA: 32] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Prasad BV, Balaram P. The stereochemistry of peptides containing alpha-aminoisobutyric acid. CRC CRITICAL REVIEWS IN BIOCHEMISTRY 1984; 16:307-48. [PMID: 6389004 DOI: 10.3109/10409238409108718] [Citation(s) in RCA: 311] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
The introduction of alpha-aminoisobutyric acid (Aib) into peptides dramatically limits the range of accessible backbone conformations. The presence of two geminal methyl groups at C alpha sterically compels Aib residues to largely favor structures in the right- or left-handed 3(10)/alpha-helical regions (phi approximately +/- 60 +/- 20 degrees, psi approximately +/- 30 +/- 20 degrees) of the peptide conformational map. Aib residues occur extensively in microbial peptides which form transmembrane channels. This observation has stimulated considerable interest in the stereochemistry of Aib peptides. This review summarizes theoretical studies on the conformations of Aib residues and examines the available data on solid-state structures, derived from single crystal X-ray diffraction studies. Crystal structures of over three dozen Aib-containing peptides, ranging in length from 2 to 11 residues, have been reported so far which exemplify various types of beta-turns, consecutive beta-turns, and helical structures. Examples of nonhydrogen bonded and cyclic structures are also described. The crystallographic results compare well with structural studies in solution, establishing that Aib peptides can provide rigid structural models for the development of spectroscopic methods of peptide conformational analysis.
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Sudha TS, Vijayakumar EK, Balaram P. Circular dichroism studies of helical oligopeptides. Can 3(10) and alpha-helical conformations be chiroptically distinguished? INTERNATIONAL JOURNAL OF PEPTIDE AND PROTEIN RESEARCH 1983; 22:464-8. [PMID: 6654594 DOI: 10.1111/j.1399-3011.1983.tb02116.x] [Citation(s) in RCA: 92] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
Circular dichroism studies of seven helical oligopeptides containing alpha-aminoisobutyric acid (Aib) in methanol and trifluoroethanol (TFE) solutions are reported. Peptides ranging from 10 to 21 residues in length have been examined. In all cases distinct negative CD bands characteristic of helical peptides are obtained at approximately 220 and 205 nm corresponding to the n-pi and pi-pi transitions, respectively. The ratio R = [theta] pi-pi is less than 1.0 for all peptides studied. Using crystal structure and n.m.r. results for a 10 residue 3(10) helical peptide and literature values for an alpha-helical 11-residue peptide, it is shown that both helical conformations yield R values of approximately 0.8 in alcoholic solvents. The CD data are considered in the light of 1H n.m.r. studies on these oligopeptides. The results suggest that 3(10) and alpha-helical conformations cannot be distinguished by CD methods.
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Jung G, Brückner H, Bosch R, Winter W, Schaal H, Strähle J. Ac-L-Ala-Aib-L-Ala-OMe: X-Ray Analysis of a Distorted β-Bend and Magnetic Nonequivalence of Aib-Methyl Groups. ACTA ACUST UNITED AC 1983. [DOI: 10.1002/jlac.198319830703] [Citation(s) in RCA: 29] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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44
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Francis AK, Iqbal M, Balaram P, Vijayan M. Crystal structure of Boc-Ala-Aib-Ala-Aib-Aib-methyl ester, a pentapeptide fragment of the channel-forming ionophore suzukacillin. Biopolymers 1983. [DOI: 10.1002/bip.360220606] [Citation(s) in RCA: 25] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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45
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Schwarz G, Savko P, Jung G. Solvent-dependent structural features of the membrane active peptide trichotoxin A40 as reflected in its dielectric dispersion. BIOCHIMICA ET BIOPHYSICA ACTA 1983; 728:419-28. [PMID: 6824666 DOI: 10.1016/0005-2736(83)90514-x] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
The dielectric dispersion of trichotoxin A40 in solvents of diverse lipophilicity (i.e. n-octanol, dioxane and mixtures of these) has been measured between 100 kHz and 50 MHz. In pure octanol also the weight average molecular weight and the concentration dependence of the circular dichroism spectrum were determined. An analysis of the data leads to the conclusion that in octanol an appreciable amount of the solute exists as single monomeric particles which are about 30 A long and 12.5 A in diameter. There is a dipole moment parallel to the long axis. In addition the evidence points at the presence of small aggregates (mainly dimers and trimers) formed by some kind of head-to-tail association. Evidently dioxane added to octanol favors a different structure of the trichotoxin monomer. It is apparently involved in another aggregation process resulting in aggregates of large size but comparatively low dipole moments.
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Jung G, Bosch R, Katz E, Schmitt H, Voges KP, Winter W. Stabilizing effects of 2-methylalanine residues on ?-turns and ?-helices. Biopolymers 1983. [DOI: 10.1002/bip.360220133] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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47
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Vijayakumar E, Balaram P. Solution conformations of penta and heptapeptides containing repetitive α-aminoisobutyryl-l-alanyl and α -aminoisobutyryl-l-valyl sequences. Tetrahedron 1983. [DOI: 10.1016/s0040-4020(01)91984-2] [Citation(s) in RCA: 34] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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48
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Brückner H, Jung G. Synthesis of L-Prolyl-leucyl-α-aminoisobutyryl-α-amino-isobutyryl-glutamyl-valinol and Proof of Identity with the Isolated C-Terminal Fragment of Trichotoxin A-40. ACTA ACUST UNITED AC 1982. [DOI: 10.1002/jlac.198219820909] [Citation(s) in RCA: 25] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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49
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Schoknecht W, Albert K, Jung G, Bayer E. Aufbau des Insulinsegments B 13–20 nach der Liquid-Phase-Methode und Synthesekontrolle der trägergebundenen Peptide durch13C-NMR-Spektroskopie. ACTA ACUST UNITED AC 1982. [DOI: 10.1002/jlac.198219820811] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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50
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Schmitt H, Winter W, Bosch R, Jung G. The α-helical conformation of the undecapeptide boc-l-Ala-[Aib-Ala]2-Glu(OBzl)-Ala-[Aib-Ala]2-OMe: Synthesis, X-Ray crystal structure, and conformation in solution. ACTA ACUST UNITED AC 1982. [DOI: 10.1002/jlac.198219820708] [Citation(s) in RCA: 30] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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