On ‐resin N‐formylation of peptides: a head‐to‐head comparison of reagents in solid‐phase synthesis of ligands for formyl peptide receptors
General conditions for efficient on‐resin N‐formylation of peptides were identified by screening of a number of reagents comprising aliphatic formates (ethyl formate, 2,2,2‐trifluoroethyl formate, and cyanomethyl formate), aromatic esters (phenyl formate and p‐nitrophenyl formate), and N‐formylimidazole and in situ activation of formic acid with the coupling reagent 1‐ethyl‐3‐(3‐dimethylaminopropyl)carbodiimide. Initially, reaction time and influence of solvent were examined for the formylation of a short model peptide. The most efficient reagents were examined further by using different linkers and solid...
Source: Journal of Peptide Science - April 19, 2017 Category: Biochemistry Authors: Simon Bendt Christensen, Anna Mette Hansen, Henrik Franzyk Tags: Research Article Source Type: research
Issue information
(Source: Journal of Peptide Science)
Source: Journal of Peptide Science - April 19, 2017 Category: Biochemistry Tags: Issue Information Source Type: research
Computational prediction of the optimal oligomeric state for membrane ‐inserted β‐barrels of protegrin‐1 and related mutants
In this study, we performed molecular dynamics simulations of β‐barrels of protegrin and three related mutants (v14v16l, v14v16a, and r4n) in NCNC parallel topology in implicit membrane pores of varying radius and curvature for oligomeric numbers 6–14. We then identified the optimal pore radius and curvature values for all constructs and determined the total effective energy and the translational and rotational entropic losses. These, along with an estimate of membrane deformation free energy from experimental line tension values, provided an estimate of the overall energetics of formation of each pore state. The resu...
Source: Journal of Peptide Science - April 6, 2017 Category: Biochemistry Authors: Richard Lipkin, Themis Lazaridis Tags: Special Issue Article Source Type: research
Issue information
(Source: Journal of Peptide Science)
Source: Journal of Peptide Science - April 6, 2017 Category: Biochemistry Tags: Issue Information Source Type: research
Effects of replacement and addition of an amino acid contained in a cyclic peptide corresponding to a β‐hairpin loop sequence of human EGF receptor
Effects of replacement and addition of an amino acid in a cyclic decapeptide 1 (cyclic‐CYNPTTYQMC) for inhibitory activity to dimerization of human epidermal growth factor receptor (EGFR) were examined. By alanine scanning of 1 corresponding to the arm structure (residues 246–254) of a β‐hairpin loop sequence (residues 242–259) of EGFR, it was confirmed that replacement of any amino acid in the loop structure lowered the dimerization inhibitory activity of 1. Among the residues examined, Tyr at position 246 and Thr at 250 were found to be crucial for dimer formation. Addition of an amino acid to the N‐terminus o...
Source: Journal of Peptide Science - April 4, 2017 Category: Biochemistry Authors: Kazuya Kobayashi, Takaaki Mizuguchi, Yasunao Hattori, Naho Ohara, Ryunosuke Ninomiya, Mika Iida, Honami Ooe, Yukako Yamazaki, Minami Takata, Hirokazu Tamamura, Kenichi Akaji Tags: Special Issue Article Source Type: research
Impact of the amino acid sequence on the conformation of side chain lactam ‐bridged octapeptides
In conclusion, the Lys‐Asp‐(i,i + 4)‐lactam bridge may succeed or fail in the stabilization of short helices, depending on the primary structure. Moreover, computational methods may be valuable tools to discriminate helix‐prone from non‐helix‐prone peptide‐based macrolactams. Copyright © 2017 European Peptide Society and John Wiley & Sons, Ltd.
A series of peptide‐based macrolactams has been synthesized, and their helix propensity has been assessed by CD spectroscopy and computational methods. The results indicate that the conformational features of the macrolactams are significantly affected by bot...
Source: Journal of Peptide Science - March 29, 2017 Category: Biochemistry Authors: Saskia Neukirchen, Viktoria Krieger, Cornelia Roschger, Mario Schubert, Brigitta Els ässer, Chiara Cabrele Tags: Special Issue Article Source Type: research
N ‐terminal chemical protein labeling using the naturally split GOS‐TerL intein
Chemoselective and regioselective chemical protein labeling is of great importance, yet no current technique is sufficiently general and simple to perform. Protein trans‐splicing by split inteins can be used to ligate short tags with chemical labels to either the N or the C terminus of a protein. The CysTag approach exploits split intein fragments without a cysteine fused with such a short tag containing a single cysteine that is easily amenable to selective modification using classical cysteine bioconjugation. Labeling of the protein of interest is achieved through transfer of the pre‐labeled tag by protein trans‐sp...
Source: Journal of Peptide Science - March 23, 2017 Category: Biochemistry Authors: Anne ‐Lena Bachmann, Henning D. Mootz Tags: Special Issue Article Source Type: research
Antimicrobial activity and stability of protonectin with D ‐amino acid substitutions
The misuse and overuse of antibiotics result in the emergence of resistant bacteria and fungi, which make an urgent need of the new antimicrobial agents. Nowadays, antimicrobial peptides have attracted great attention of researchers. However, the low physiological stability in biological system limits the application of naturally occurring antimicrobial peptides as novel therapeutics. In the present study, we synthesized derivatives of protonectin by substituting all the amino acid residues or the cationic lysine residue with the corresponding D‐amino acids. Both the D‐enantiomer of protonectin (D‐prt) and D‐Lys‐...
Source: Journal of Peptide Science - March 15, 2017 Category: Biochemistry Authors: Shuai Qiu, Ranran Zhu, Yanyan Zhao, Xiaoping An, Fengjing Jia, Jinxiu Peng, Zelin Ma, Yuanyuan Zhu, Jiayi Wang, Jinhuan Su, Qingjun Wang, Hailin Wang, Yuan Li, Kairong Wang, Wenjin Yan, Rui Wang Tags: Research Article Source Type: research
The effect of a beta ‐lactamase inhibitor peptide on bacterial membrane structure and integrity: a comparative study
Co‐administration of beta‐lactam antibiotics and beta‐lactamase inhibitors has been a favored treatment strategy against beta‐lactamase‐mediated bacterial antibiotic resistance, but the emergence of beta‐lactamases resistant to current inhibitors necessitates the discovery of novel non‐beta‐lactam inhibitors. Peptides derived from the Ala46–Tyr51 region of the beta‐lactamase inhibitor protein are considered as potent inhibitors of beta‐lactamase; unfortunately, peptide delivery into the cell limits their potential. The properties of cell‐penetrating peptides could guide the design of beta‐lactamas...
Source: Journal of Peptide Science - March 15, 2017 Category: Biochemistry Authors: Begum Alaybeyoglu, Bilge Gedik Uluocak, Berna Sariyar Akbulut, Elif Ozkirimli Tags: Research Article Source Type: research
Fluorescent and luminescent fusion proteins for analyses of amyloid beta peptide aggregation
This study would be a promising method for analyzing the aggregation state of a particular amyloid protein/peptide (monomer, oligomer, or fibril), as well as the distribution of the amyloid protein/peptide within and at the cell surface, by using a single fusion protein. Copyright © 2017 European Peptide Society and John Wiley & Sons, Ltd.
Fluorescent and luminescent fusion proteins were constructed to analyze amyloid beta (Aβ) peptide aggregation. Aβ localization was determined by monitoring the fluorescence of the fusion proteins, and regions of aggregation were discriminated from regions of localization on the b...
Source: Journal of Peptide Science - March 1, 2017 Category: Biochemistry Authors: Kenji Usui, Masayasu Mie, Takashi Andou, Hisakazu Mihara, Eiry Kobatake Tags: Special Issue Article Source Type: research
Synthesis of hemithioindigo ‐based chromopeptides by using the Tmb auxiliary in native chemical ligation studies
The 4,5,6‐trimethoxy‐2‐mercaptobenzyl auxiliary was used in auxiliary‐based native chemical ligation reactions with Boc‐protected pHTI and mHTI ω‐amino acid thioesters 2a,b for the construction of small hemithioindigo (HTI)‐based chromopeptides 6a,b with a class 1 PDZ binding motif. While reversible tris(2‐carboxyethyl)phosphine (TCEP)‐HTI adduct formation required moderate use of access TCEP, the Na ascorbate concentration was broadly varied for optimization of the reaction conditions. In the studies presented, the mHTI ω‐amino acid thioester 2b proved to be slightly less reactive than the pHTI ω‐...
Source: Journal of Peptide Science - March 1, 2017 Category: Biochemistry Authors: S. Kitzig, K. R ück‐Braun Tags: Special Issue Article Source Type: research
Generation of monoclonal antibodies against mitocryptide ‐2: toward a new strategy to investigate the biological roles of cryptides
We recently identified a novel family of neutrophil‐activating peptides including mitocryptide‐1 and mitocryptide‐2 (MCT‐2) that are endogenously produced from various mitochondrial proteins. Among them, MCT‐2 is an N‐formylated pentadecapeptide derived from mitochondrial cytochrome b and is found to promote neutrophilic migration and phagocytosis efficiently. Signaling mechanisms of neutrophil activation by MCT‐2 have been investigated at the cellular level, and MCT‐2 has been demonstrated to be an endogenous specific ligand for formyl peptide receptor‐2 (also referred to as formyl peptide receptor‐lik...
Source: Journal of Peptide Science - March 1, 2017 Category: Biochemistry Authors: Tatsuya Hattori, Takenori Yamada, Hiroki Morikawa, Takayuki Marutani, Koki Tsutsumi, Kodai Nishino, Toshihiro Shimizu, Yoshisuke Nishi, Yoshiaki Kiso, Hidehito Mukai Tags: Special Issue Article Source Type: research
Biological characterization of novel nitroimidazole ‐peptide conjugates in vitro and in vivo
Recently, we reported on the design of a multimodal peptide conjugate useful as delivery platform for targeting hypoxic cells. A nitroimidazole (2‐(2‐nitroimidazol‐1‐yl)acetic acid, NIA) moiety, which is selectively entrapped in hypoxic cells, was coupled to a cell‐penetrating peptide serving as the transporter. Furthermore, attachment of a bifunctional linker allowed the introduction of a diagnostic or therapeutic radiometal. However, although selective tumor accumulation could be detected in vivo, a fast renal clearance of the compound was observed. The present study aims to improve the system by using the more...
Source: Journal of Peptide Science - March 1, 2017 Category: Biochemistry Authors: Ralf Bergmann, Katrin Splith, Jens Pietzsch, Michael Bachmann, Ines Neundorf Tags: Special Issue Article Source Type: research
Role of single disulfide linkages in the folding and activity of scyllatoxin ‐based BH3 domain mimetics
This study underscores the importance of structural dynamics in BH3:Bcl‐2 interactions and further validates ScTx‐based ligands as potential modulators of anti‐apoptotic Bcl‐2 function. Copyright © 2017 European Peptide Society and John Wiley & Sons, Ltd.
Structural variants of synthetic peptides based on scyllatoxin (ScTx) designed to mimic the helical BH3 interaction domain of the pro‐apoptotic Bcl‐2 protein Bax were developed and the contribution of single disulfides in the folding and function of ScTx‐Bax BH3 mimetics was investigated. It was dterminded that the position of the disulfide linkages ha...
Source: Journal of Peptide Science - March 1, 2017 Category: Biochemistry Authors: Danushka Arachchige, M. Margaret Harris, Zachary Coon, Jacob Carlsen, Justin M. Holub Tags: Rapid Communication Source Type: research
Bike peptides: a ride through the membrane
Several natural peptides have a biaryl or biaryl ether motif in their biologically active structures. A model bicyclic pentapeptide containing a biaryl bridge has been synthesized by solid‐phase peptide synthesis combining on‐resin Suzuki and Miyaura cross‐coupling reactions. Its biological properties in terms of permeability, stability and cytotoxicity have been studied, demonstrating the positive contribution of the biaryl bridge, excellent membrane penetration and serum stability Copyright © 2017 European Peptide Society and John Wiley & Sons, Ltd.
A bike peptide displaying a biaryl bridge has been synthesiz...
Source: Journal of Peptide Science - February 28, 2017 Category: Biochemistry Authors: J úlia García‐Pindado, Soledad Royo, Meritxell Teixidó, Ernest Giralt Tags: Special Issue Article Source Type: research
