Methoxinine – an alternative stable amino acid substitute for oxidation‐sensitive methionine in radiolabelled peptide conjugates
We report here the use of methoxinine (Mox), a non‐canonical amino acid that resembles more closely the electronic properties of Met in comparison to Nle. Specifically, we replaced Met15 by Mox15 and Nle15 in the binding sequence of a radiometal‐labelled human gastrin derivative [d‐Glu10]HG(10‐17), named MG11 (d‐Glu‐Ala‐Tyr‐Gly‐Trp‐Met‐Asp‐Phe‐NH2). A comparison of the physicochemical properties of 177Lu‐DOTA[X15]MG11 (X = Met, Nle, Mox) in vitro (cell internalization/externalization properties, receptor affinity (IC50), blood plasma stability and logD) showed that Mox indeed represents a su...
Source: Journal of Peptide Science - October 31, 2016 Category: Biochemistry Authors: Nathalie M. Grob, Martin Behe, Elisabeth Guggenberg, Roger Schibli, Thomas L. Mindt Tags: Research Article Source Type: research
Acetylation dictates the morphology of nanophase biosilica precipitated by a 14 ‐amino acid leucine–lysine peptide
N‐terminal acetylation is a commonly used modification technique for synthetic peptides, mostly applied for reasons of enhanced stability, and in many cases regarded as inconsequential. In engineered biosilification – the controlled deposition of silica for nanotechnology applications by designed peptides – charged groups often play a deciding role. Here we report that changing the charge by acetylation of a 14‐amino acid leucine–lysine (LK) peptide dramatically changes the morphology of precipitated biosilica; acetylated LK peptides produce nano‐spheres, whereas nano‐wires are precipitated by the same peptid...
Source: Journal of Peptide Science - October 31, 2016 Category: Biochemistry Authors: Helmut Lutz, Vance Jaeger, Mischa Bonn, Jim Pfaendtner, Tobias Weidner Tags: Special Issue Article Source Type: research
Biological and structural effects of the conjugation of an antimicrobial decapeptide with saturated, unsaturated, methoxylated and branched fatty acids
In this study, a decapeptide named A2 (IKQVKKLFKK) was conjugated at the N‐terminus with saturated, unsaturated, methoxylated and methyl ‐branched fatty acids of different chain lengths (C8 – C20), the antimicrobial and structural properties of the lipopeptides being then investigated. The attachment of the fatty acid chain significantly improved the antimicrobial activity of A2 against bacteria, and so, endowed it with moderated antifungal activity against yeast strains belonging to genus Candida. Lipopeptides containing hydrocarbon chain lengths between C8 and C14 were the best antibacterial compounds (MIC = 0.7 ...
Source: Journal of Peptide Science - October 31, 2016 Category: Biochemistry Authors: Mar ía Verónica Húmpola, María Carolina Rey, Nestor M. Carballeira, Arturo Carlos Simonetta, Georgina Guadalupe Tonarelli Tags: Research Article Source Type: research
En route towards the peptide γ‐helix: X‐ray diffraction analyses and conformational energy calculations of Adm‐rich short peptides
We performed the solution‐phase synthesis of a set of model peptides, including homo‐oligomers, based on the 2‐aminoadamantane‐2‐carboxylic acid (Adm) residue, an extremely bulky, highly lipophilic, tricyclic, achiral, Cα‐tetrasubstituted α‐amino acid. In particular, for the difficult peptide coupling reaction between two Adm residues, we took advantage of the Meldal's α‐azidoacyl chloride approach. Most of the synthesized Adm peptides were characterized by single‐crystal X‐ray diffraction analyses. The results indicate a significant propensity for the Adm residue to adopt γ‐turn and γ‐turn‐l...
Source: Journal of Peptide Science - October 31, 2016 Category: Biochemistry Authors: Daniela Mazzier, Luigi Grassi, Alessandro Moretto, Carlos Alem án, Fernando Formaggio, Claudio Toniolo, Marco Crisma Tags: Special Issue Article Source Type: research
Peptide hydrogel in vitro non ‐inflammatory potential
Peptide‐based hydrogels have attracted significant interest in recent years as these soft, highly hydrated materials can be engineered to mimic the cell niche with significant potential applications in the biomedical field. Their potential use in vivo in particular is dependent on their biocompatibility, including their potential to cause an inflammatory response. In this work, we investigated in vitro the inflammatory potential of a β‐sheet forming peptide (FEFEFKFK; F: phenylalanine, E: glutamic acid; K: lysine) hydrogel by encapsulating murine monocytes within it (3D culture) and using the production of cytokines, ...
Source: Journal of Peptide Science - October 31, 2016 Category: Biochemistry Authors: A. Markey, V. L. Workman, I. A. Bruce, T. J. Woolford, B. Derby, A. F. Miller, S. H. Cartmell, A. Saiani Tags: Special Issue Article Source Type: research
Computational resources and tools for antimicrobial peptides
This article reviews the advances of AMP databases and computational tools for the prediction and design of new active AMPs. Copyright © 2016 European Peptide Society and John Wiley & Sons, Ltd.
Antimicrobial peptides (AMPs) have been considered to be promising substitutes of conventional antibiotics to combat the challenge of antibiotic resistance. However, most AMPs have modest direct antimicrobial activity, and their mechanisms of action are still poorly understood. This review presents the advances of antimicrobial peptide databases and computational tools for the prediction and design of new active AMPs. The com...
Source: Journal of Peptide Science - October 31, 2016 Category: Biochemistry Authors: Shicai Liu, Linlin Fan, Jian Sun, Xingzhen Lao, Heng Zheng Tags: Review Source Type: research
The heparin ‐binding domain of HB‐EGF as an efficient cell‐penetrating peptide for drug delivery
Cell‐penetrating peptides (CPPs) have been shown to be potential drug carriers for cancer therapy. The inherently low immunogenicity and cytotoxicity of human‐derived CPPs make them more suitable for intracellular drug delivery compared to other delivery vehicles. In this work, the protein transduction ability of a novel CPP (termed HBP) derived from the heparin‐binding domain of HB‐EGF was evaluated. Our data shows, for the first time, that HBP possesses similar properties to typical CPPs and is a potent drug delivery vector for improving the antitumor activity of impermeable MAP30. The intrinsic bioactivities of ...
Source: Journal of Peptide Science - October 13, 2016 Category: Biochemistry Authors: Zhao Luo, Xue ‐Wei Cao, Chen Li, Miao‐Dan Wu, Xu‐Zhong Yang, Jian Zhao, Fu‐Jun Wang Tags: Research Article Source Type: research
Hydrophobic and electrostatic interactions between cell penetrating peptides and plasmid DNA are important for stable non ‐covalent complexation and intracellular delivery
Cell penetrating peptides are useful tools for intracellular delivery of nucleic acids. Delivery of plasmid DNA, a large nucleic acid, poses a challenge for peptide mediated transport. The paper investigates and compares efficacy of five novel peptide designs for complexation of plasmid DNA and subsequent delivery into cells. The peptides were designed to contain reported DNA condensing agents and basic cell penetrating sequences, octa‐arginine (R8) and CHK6HC coupled to cell penetration accelerating peptides such as Bax inhibitory mutant peptide (KLPVM) and a peptide derived from the Kaposi fibroblast growth factor (kFG...
Source: Journal of Peptide Science - October 9, 2016 Category: Biochemistry Authors: Archana Upadhya, Preeti C. Sangave Tags: Research Article Source Type: research
Issue Information
(Source: Journal of Peptide Science)
Source: Journal of Peptide Science - October 9, 2016 Category: Biochemistry Tags: Issue Information Source Type: research
Oxime ligation in acetic acid: efficient synthesis of aminooxy ‐peptide conjugates
Oxime ligation is a powerful tool in various bioconjugation strategies. Nevertheless, high reaction rates and quantitative yields are typically reported for aldehyde‐derived compounds. In contrary, keto groups react much slower, with quantitative yields achieved at 5 h for low‐molecular weight compounds and more than 15 h for polymers or dendrimers. In this communication, we report that oxime ligation proceeds rapidly with quantitative (>95%) conversion within 1.5–2 h in pure acetic acid. The practical utility of suggested technique is illustrated by the synthesis of peptide‐steroid and peptide‐polymer c...
Source: Journal of Peptide Science - October 3, 2016 Category: Biochemistry Authors: Pavel S. Chelushkin, Maria V. Leko, Marina Yu Dorosh, Sergey V. Burov Tags: Rapid Communication Source Type: research
SNaPe: a versatile method to generate multiplexed protein fusions using synthetic linker peptides for in vitro applications
We report a modular approach to fusion protein generation using a synthetic peptide to link separately expressed proteins: SNaPe (Sortase‐mediated and Native chemical ligation using synthetic Peptide linkers). This uses separate linking steps – sortase‐mediated and native chemical ligation – with a library of peptide linkers to generate libraries of fusion proteins. We have demonstrated the viability of SNaPe to generate libraries of fusion protein constructs taken from the biosynthetic enzymes responsible for late stage aglycone biosynthesis (Source: Journal of Peptide Science)
Source: Journal of Peptide Science - September 30, 2016 Category: Biochemistry Authors: Veronika Ulrich, Max J. Cryle Tags: Research Article Source Type: research
Kinetics of the competitive reactions of isomerization and peptide bond cleavage at l ‐α‐ and d‐β‐aspartyl residues in an αA‐crystallin fragment
d‐β‐aspartyl (Asp) residue has been found in a living body such as aged lens crystallin, although l‐α‐amino acids are constituents in natural proteins. Isomerization from l‐α‐ to d‐β‐Asp probably modulates structures to affect biochemical reactions. At Asp residue, isomerization and peptide bond cleavage compete with each other. To gain insight into how fast each reaction proceeds, the analysis requires the consideration of both pathways simultaneously and independently. No information has been provided, however, about these competitive processes because each reaction has been studied separately. The co...
Source: Journal of Peptide Science - September 30, 2016 Category: Biochemistry Authors: Kenzo Aki, Emiko Okamura Tags: Research Article Source Type: research
Conformational analysis of a modified RGD adhesive sequence
The conformational preferences of the Arg‐GlE‐Asp sequence, where GlE is an engineered amino acid bearing a 3,4‐ethylenedioxythiophene (EDOT) ring as side group, have been determined combining density functional theory calculations with a well‐established conformational search strategy. Although the Arg‐GlE‐Asp sequence was designed to prepare a conducting polymer–peptide conjugate with excellent electrochemical and bioadhesive properties, the behavior of such hybrid material as adhesive biointerface is improvable. Results obtained in this work prove that the bioactive characteristics of the parent Arg‐Gly...
Source: Journal of Peptide Science - September 30, 2016 Category: Biochemistry Authors: Jordi Triguero, David Zanuy, Carlos Alem án Tags: Special Issue Article Source Type: research
Gadolinium containing telechelic PEG ‐polymers end‐capped by di‐phenylalanine motives as potential supramolecular MRI contrast agents
Telechelic PEG‐polymers end‐capped by diphenylalanine (FF) motives and containing a DOTA‐Gd complex, bound on a lysine side chain at the centre of peptide moiety, are studied for their assembling properties and for the relaxometric behavior. The observed variations in terms of relaxivity are correlated to the assembling properties of the aggregates by using several techniques: fluorescence, Circular Dichroism (CD) and Fourier Transform Infrared (FTIR) for aggregation tendency and secondary structure determination; Dynamic Light Scattering (DLS) and Transmission Electron Microscopy (TEM) for morphological definition. ...
Source: Journal of Peptide Science - September 30, 2016 Category: Biochemistry Authors: Carlo Diaferia, Eliana Gianolio, Antonella Accardo, Giancarlo Morelli Tags: Special Issue Article Source Type: research
Weighing biointeractions between fibrin(ogen) and clot ‐binding peptides using microcantilever sensors
Peptides homing tumor vasculature are considered promising molecular imaging agents for cancer detection at an early stage. In addition to their high binding affinity, improved tissue penetrating ability, and low immunogenicity, they can deliver targeted anticancer drugs, thus expanding therapeutic treatments. Among those, CREKA, a linear peptide that specifically binds to clotted‐plasma proteins in tumor vessels, has been recently employed to design bioactive systems able to target different cancer types. Within this context, this paper explores the biorecognition event between CR(NMe)EKA, an engineered CREKA‐analog b...
Source: Journal of Peptide Science - September 30, 2016 Category: Biochemistry Authors: Anna Puiggal í‐Jou, Luis J. Valle, Carlos Alemán, Maria M. Pérez‐Madrigal Tags: Special Issue Article Source Type: research
