Journal of Peptide Science

Cover image for Vol. 18 Issue 1

January 2012

Volume 18, Issue 1

Pages 1–72

  1. Research Articles

    1. Top of page
    2. Research Articles
    1. 2,2′-Dithiobis(5-nitropyridine) (DTNP) as an effective and gentle deprotectant for common cysteine protecting groups (pages 1–9)

      Alayne L. Schroll, Robert J. Hondal and Stevenson Flemer Jr.

      Article first published online: 14 NOV 2011 | DOI: 10.1002/psc.1403

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      The scope and limitations of a gentle and universal cysteine S-deprotection technique is presented in which all commercially available Cys protecting groups are assayed as to the deprotective potentital toward DTNP-mediated removal conditions.

    2. Identification and characterization of two novel antimicrobial peptides, temporin-Ra and temporin-Rb, from skin secretions of the marsh frog (Rana ridibunda) (pages 10–16)

      Ahmad Asoodeh, Hadi Zare Zardini and JamshidKhan Chamani

      Article first published online: 29 SEP 2011 | DOI: 10.1002/psc.1409

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      Two novel antimicrobial peptides from the skin secretions of Rana ridibunda, named temporin-Ra and temporin-Rb, were purified and characterized. These peptides have inhibitory effects on both gram-negative, gram-positive bacteria and two antibiotic-resistant strains prevalent in hospitals. Minimum inhibition concentration (MIC) values of these peptides are suitable for potent antimicrobial peptides. The peptides do not have hemolytic effect against human red blood cells (RBC) in their MIC values. These peptides showed 1.3% hemolysis at a concentration of 60 µg/ml.

    3. In silico predictions of 3D structures of linear and cyclic peptides with natural and non-proteinogenic residues (pages 17–24)

      Jérôme Beaufays, Laurence Lins, Annick Thomas and Robert Brasseur

      Article first published online: 27 OCT 2011 | DOI: 10.1002/psc.1410

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      We extended the use of PepLook, an in silico procedure for the prediction of three-dimensional models of linear peptides to the prediction of three-dimensional models of cyclic peptides and peptides with non-proteinogenic amino acids. We compared the calculated models with NMR and X-ray models, and the cyclic peptides were compared with models predicted by other in silico procedures (PEP-FOLD and I-TASSER).

    4. Enhancement of the inhibitory effect of an IL-15 antagonist peptide by alanine scanning (pages 25–29)

      Alicia Santos Savio, Osvaldo Reyes Acosta, Haydee Gerónimo Pérez, Yunier Rodríguez Álvarez, Araceli Chico, Hilda Garay Pérez, Miriam Ojeda Ojeda, Celia Aurora Arrieta Aguero, Miguel Estévez and Gerardo Guillen Nieto

      Article first published online: 2 NOV 2011 | DOI: 10.1002/psc.1411

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      IL-15 is a potential target in rheumatoid arthritis. We had identified a peptide (P8) which inhibits binding of IL-15 to IL-15Rα and affects IL-15 biological activity. Here, we studied P8 peptide analogs based on Ala scanning and other punctual mutations. As a result, we found a more active peptide inhibiting both IL-15 biological activity and TNFα secretion by synovial cells

    5. On-resin synthesis of novel arginine-isostere peptides bearing substituted amidine headgroups (pages 30–36)

      Stevenson Flemer Jr. and José S. Madalengoitia

      Article first published online: 27 OCT 2011 | DOI: 10.1002/psc.1412

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      An amidinylation methodology is presented, which allows for the installation of amidinylated Arg isosteres into model peptides. N-Pmc-substituted thioamides are condensed with resin-bound Orn amines using Mukaiyama's reagent as thiophile.

    6. Synthesis and preliminary conformational analysis of TOAC spin-labeled analogues of the medium-length peptaibiotic tylopeptin B (pages 37–44)

      Marina Gobbo, Elisabetta Merli, Barbara Biondi, Simona Oancea, Antonio Toffoletti, Fernando Formaggio and Claudio Toniolo

      Article first published online: 2 NOV 2011 | DOI: 10.1002/psc.1413

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      A set of analogues of the 14-residue peptaibol tylopeptin B, containing the stable free-radical TOAC at one or two selected positions, was synthesized by the solid-phase methodology. A solution conformational analysis performed by FTIR absorption and CD suggests that all of the TOAC analogues retain the conformational preference of the parent peptide, resulting mostly to be helical in solution. Also, they do exhibit membrane-modifying properties comparable with those of tylopeptin B.

    7. The structure and assembly model of the third transmembrane domain of Slc11a1 in SDS micelles revealed by NMR study of the Leu-substituted peptide (pages 45–51)

      Shuyan Xiao, Lei Yang and Fei Li

      Article first published online: 3 NOV 2011 | DOI: 10.1002/psc.1414

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      The NMR study reveals that TMD3 segment of Slc11a1 has a strong propensity to aggregate to form an α-helix bundle in the micelle state by Leu-zipper interaction. The simultaneous substitutions of L136A/L140A cause disassociation of the peptide assembly while maintaining its α-helical structure.

    8. Sialic acid and sialyl-lactose glyco-conjugates: design, synthesis and binding assays to lectins and swine influenza H1N1 virus (pages 52–58)

      Stella Zevgiti, Juliana Gonzalez Zabala, Ayub Darji, Ursula Dietrich, Eugenia Panou-Pomonis and Maria Sakarellos-Daitsiotis

      Article first published online: 2 NOV 2011 | DOI: 10.1002/psc.1415

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      Sialyl-lactose glyco-conjugates bind lectins and swine influenza H1N1 virus.

    9. Interference of low-molecular substances with the thioflavin-T fluorescence assay of amyloid fibrils (pages 59–64)

      Andra Noormägi, Kateryna Primar, Vello Tõugu and Peep Palumaa

      Article first published online: 14 NOV 2011 | DOI: 10.1002/psc.1416

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      Basic Blue 41, Basic Blue 12, Azure C and Tannic acid decrease fluorescence intensity of ThT bound to insulin fibrils.

      In insulin fibrillization assay monitored by ThT fluorescence, these compounds show apparent inhibition of fibrillization.

      Unlike to true inhibitors, these compounds did not decreased the fibrillization rate or increased the lag-period of insulin fibrillization.

    10. Solid-state NMR reveals differences in the packing arrangements of peptide aggregates derived from the aortic amyloid polypeptide medin (pages 65–72)

      Hannah A. Davies, Jillian Madine and David A. Middleton

      Article first published online: 21 NOV 2011 | DOI: 10.1002/psc.1418

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      Solid-state NMR is used to examine the structure and dynamics of fibrils formed by the 50-residue aortic amyloid polypeptide medin and aggregates formed by 21-residue and 8-residue medin fragments. It is shown that medin and the larger fragment adopt different packing arrangements to the shorter medin peptide. The results imply that at least two of the three predicted amyloidogenic regions of medin are required for the formation and elongation of fibres observed in the disease state.