Journal of Peptide Science

Cover image for Vol. 17 Issue 8

August 2011

Volume 17, Issue 8

Pages 545–600

  1. Research Articles

    1. Top of page
    2. Research Articles
    1. Conformational constraints in angiotensin IV to probe the role of Tyr2, Pro5 and Phe6 (pages 545–553)

      Aneta Lukaszuk, Heidi Demaegdt, Isabelle Van den Eynde, Patrick Vanderheyden, Georges Vauquelin and Dirk Tourwé

      Article first published online: 28 APR 2011 | DOI: 10.1002/psc.1365

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      To develop selective Ang IV analogs, conformationally constrained amino acids were introduced. No modification was allowed for Tyr1, Pro5 replacement by Acpc was tolerated, and only e-β-MePhe6 substitution resulted in an analog with high IRAP potency and selectivity.

    2. Molecular modeling study of the opioid receptor interactions with series of cyclic deltorphin analogues (pages 554–564)

      Magdalena J. Ślusarz

      Article first published online: 28 APR 2011 | DOI: 10.1002/psc.1371

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      In this study, ten tetra- and heptapeptide analogues of deltorphin containing the urea bridges between residues 2 and 4 have been docked into the δ- and µ-opioid receptors to explain their different biological activities. The important factors explaining particular ligand activity such as free energy of binding, conformation of the ligand, its location inside the binding pocket as well as the number and strength of the receptor-ligand interactions have been discussed. Several different binding modes for investigated ligands have been proposed.

    3. Selection and characterization of a 7-mer peptide binding to divalent cations (pages 565–568)

      Daeyoung Han, Seong Huh and Heejoon Myung

      Article first published online: 13 MAY 2011 | DOI: 10.1002/psc.1374

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      A 7-mer peptide (S-T-L-P-L-P-P) was selected for binding to divalent cations from phage display peptide library. Pro residues may chelate divalent cations, while the structure formed by the peptide is also important for the binding process.

    4. Development of [Ile40]HTLV-I protease inhibition assay using novel fluorogenic and chromogenic substrate (pages 569–575)

      Henri-Obadja Kumada, Jeffrey-Tri Nguyen, Taeko Kakizawa, Koushi Hidaka, Tooru Kimura, Yoshio Hayashi and Yoshiaki Kiso

      Article first published online: 13 MAY 2011 | DOI: 10.1002/psc.1375

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      In HTLV-I protease assay, a bifunctional fluorogenic and chromogenic substrate was designed, synthesized and found to enhance both UV and fluorescence detection over a conventional mono-functional chromogenic substrate. A newly established HTLV-I protease inhibition assay using a stable L40I mutant HTLV-I protease and the fluorescent substrate requires distinctively less protease, substrate, inhibitor and assay time than the previous methods. The assay is more cost-effective and time-efficient while being reproducible and less labor-intensive.

    5. An improved synthesis of (2S, 4S)- and (2S, 4R)-2-amino-4-methyldecanoic acids: assignment of the stereochemistry of culicinins (pages 576–580)

      Wei Zhang, Ning Ding and Yingxia Li

      Article first published online: 6 JUN 2011 | DOI: 10.1002/psc.1376

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      An improved synthesis of (2S, 4S)- and (2S, 4R)-2-amino-4-methyldecanoic acids was accomplished using a glutamate derivative as starting material and Evans' asymmetric alkylation as the decisive step. The NMR data of the two diastereomers were measured and compared with those of the natural product. As a result, the stereochemistry of this novel amino acid unit in culicinins was assigned as (2S, 4R).

    6. Synthetic studies toward labionin, a new α,α-disubstituted amino acid from type III lantibiotic labyrinthopeptin A2 (pages 581–584)

      Georg M. Sambeth and Roderich D. Süssmuth

      Article first published online: 6 JUN 2011 | DOI: 10.1002/psc.1378

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      The labyrinthopeptins are a new class of lantibiotics containing two identical quaternary α,α-disubstituted amino acids, named labionin (Lab). The synthetic formation of this unique structural feature represents the key step in the total synthesis of these polycyclic peptides. In this report we describe the synthesis of an orthogonally protected α,α-disubstituted amino acid building block serving as labionin precursor for the future assembly of labyrinthopeptin A2 and of other labyrinthopeptin derivatives.

    7. Synthesis, preferred conformation, protease stability, and membrane activity of heptaibin, a medium-length peptaibiotic (pages 585–594)

      Marta De Zotti, Barbara Biondi, Cristina Peggion, Yoonkyung Park, Kyung-Soo Hahm, Fernando Formaggio and Claudio Toniolo

      Article first published online: 14 APR 2011 | DOI: 10.1002/psc.1364

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      The synthesis of heptaibin was performed. This peptaibiotic was found to be helical, amphiphilic, nonhemolytic, and resistant to proteolytic degradation. We believe that these properties, combined with its Gram-positive selective antimicrobial activity, are a good starting point for the development of a new class of peptide-based antibacterial drugs.

    8. Increasing the hydrolysis constant of the reactive site upon introduction of an engineered Cys14[BOND]Cys39 bond into the ovomucoid third domain from silver pheasant (pages 595–600)

      Hikaru Hemmi, Takashi Kumazaki, Shuichi Kojima, Takuya Yoshida, Tadayasu Ohkubo, Hideyoshi Yokosawa, Kin-ichiro Miura and Yuji Kobayashi

      Article first published online: 6 JUN 2011 | DOI: 10.1002/psc.1381

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      P14C/N39C, the CSH-motif-introducing variant of OMSVP3, exhibits significant enhanced susceptibility toward a target protease. The conversion rate from intact to modified form of P14C/N39C is faster than that for wild type. Furthermore, P14C/N39C causes relatively large increase in the hydrolysis constant(Khyd°), while it has almost the same thermal stability as wild type. There have been no examples except P14C/N39C where an engineered disulfide introduction could cause a significant increase in Khyd° without affecting any effect on the thermal stability.