Cyclization of a cell‐penetrating peptide via click‐chemistry increases proteolytic resistance and improves drug delivery
In this work we report synthesis and biological evaluation of a cell‐penetrating peptide (CPP), that is partly cyclized via a triazole bridge. Recently, beneficious properties have been reported for cyclized peptides concerning their metabolic stability and intracellular uptake. A CPP based on human calcitonin was used in this study, and side chain cyclization was achieved via copper catalyzed alkyne‐azide click reaction. Cell viability studies in several cell‐lines revealed no cytotoxic effects. Furthermore, efficient uptake in breast cancer MCF‐7 cells could be determined. Moreover, preliminary studies using this...
Source: Journal of Peptide Science - May 19, 2016 Category: Biochemistry Authors: Florian Reichart, Mareike Horn, Ines Neundorf Tags: Research Article Source Type: research
Unravelling the mechanisms of a protein refolding process based on the association of detergents and co‐solvents
A new technique associating the detergent Sodium Dodecyl Sulphate (SDS) and an alcohol‐type co‐solvent has been set up, showing an unexpected efficiency to refold several types of soluble or membrane proteins. The present contribution deepens the fundamental knowledge on the phenomena underlying this process, considering the refolding of two model peptides featuring the main protein secondary structures: α‐helix and β‐sheet. Their refolding was monitored by fluorescence and circular dichroism, and it turns out that: (i) 100% recovery of the folded structure is observed for both peptides, (ii) the highest the SDS ...
Source: Journal of Peptide Science - May 18, 2016 Category: Biochemistry Authors: C. Michaux, G. Roussel, M. Lopes‐Rodrigues, A. Matagne, E.A. Perpète Tags: Research Article Source Type: research
Editorial: A Tribute to Stephen B. H. Kent: Towards a new world of proteins enabled by chemical synthesis
(Source: Journal of Peptide Science)
Source: Journal of Peptide Science - May 9, 2016 Category: Biochemistry Authors: Luis Moroder, Ulf Diederichsen Tags: Editorial Source Type: research
Anti‐biofilm and sporicidal activity of peptides based on wheat puroindoline and barley hordoindoline proteins
This study shows that tryptophan‐rich antimicrobial peptides (AMPs), designed based on wheat puroindoline proteins, are highly effective against biofilms of Pseudomonas aeruginosa and Listeria monocytogenes and endospores of Bacillus subtilis. The results establish their potential as novel biocidal agents. (Source: Journal of Peptide Science)
Source: Journal of Peptide Science - April 30, 2016 Category: Biochemistry Authors: Nadin Shagaghi, Rebecca L. Alfred, Andrew H. A. Clayton, Enzo A. Palombo, Mrinal Bhave Tags: Research Article Source Type: research
Retraction statement: ‘S14G‐humanin inhibits Aβ1–42 fibril formation, disaggregates preformed fibrils, and protects against Aβ‐induced cytotoxicity in vitro’ by Wei Zhang, Ying Du, Miao Bai, Ye Xi, Zhuyi Li and Jianting Miao J. Peptide Sci. 2013; 19: 159–165. DOI:10.1002/psc.2484
(Source: Journal of Peptide Science)
Source: Journal of Peptide Science - April 30, 2016 Category: Biochemistry Tags: Retraction Statement Source Type: research
Identification of CRISP2 from human sperm as PSP94‐binding protein and generation of CRISP2‐specific anti‐peptide antibodies
In this study, we identified CRISP2 as a potential binding protein of PSP94 from human sperm. Further, we generated antisera capable of specifically detecting CRISP2 and not CRISP3. In this direction, specific peptides corresponding to the least conserved ion channel regulatory region were synthesized, and polyclonal antibodies were generated against the peptide in rabbits. The binding characteristics of the anti‐CRISP2 peptide antibody were evaluated using competitive ELISA. Immunoblotting experiments also confirmed that the peptide was able to generate antibodies capable of detecting the mature CRISP2 protein present i...
Source: Journal of Peptide Science - April 30, 2016 Category: Biochemistry Authors: Jenifer H. Anklesaria, Bhalchandra J. Kulkarni, Bhakti R. Pathak, Smita D. Mahale Tags: Research Article Source Type: research
Issue Information
(Source: Journal of Peptide Science)
Source: Journal of Peptide Science - April 30, 2016 Category: Biochemistry Tags: Issue Information Source Type: research
Quest for the chemical synthesis of proteins
The chemical synthesis of proteins has been the wish of chemists since the early 19th century. There were decisive methodological steps necessary to accomplish this aim. Cornerstones were the introduction of the Z‐protecting group of Bergmann and Zervas, the development of Solid‐phase Peptide Synthesis of Merrifield, and the establishment of Native Chemical Ligation by Kent. Chemical synthesis of proteins has now become generally applicable technique for the synthesis of proteins with tailor made properties which can be applied not only in vitro but also in vivo .Copyright © 2016 European Peptide Society and John Wile...
Source: Journal of Peptide Science - April 25, 2016 Category: Biochemistry Authors: Martin Engelhard Tags: Special Issue Review Source Type: research
Semi‐synthesis of a tag‐free O‐GlcNAcylated tau protein by sequential chemoselective ligation
We present the first semi‐synthesis of the full‐length tau protein carrying an O‐GlcNAc moiety at S400, a site shown to inhibit tau phosphorylation at neighboring serine residues. Native chemical ligation was combined with expressed protein ligation to obtain the desired homogeneously modified tau protein. Pure protein was finally obtained by means of a photocleavable biotin tag. (Source: Journal of Peptide Science)
Source: Journal of Peptide Science - April 11, 2016 Category: Biochemistry Authors: Sergej Schwagerus, Oliver Reimann, Clement Despres, Caroline Smet‐Nocca, Christian P. R. Hackenberger Tags: Special Issue Article Source Type: research
Peptide backbone modification in the bend region of amyloid‐β inhibits fibrillogenesis but not oligomer formation
Current evidence suggests that oligomers of the amyloid‐β (Aβ) peptide are involved in the cellular toxicity of Alzheimer's disease, yet their biophysical characterization remains difficult because of lack of experimental control over the aggregation process under relevant physiologic conditions. Here, we show that modification of the Aβ peptide backbone at Gly29 allows for the formation of oligomers but inhibits fibril formation at physiologic temperature and pH. Our results suggest that the putative bend region in Aβ is important for higher‐order aggregate formation. Copyright © 2016 European Peptide Society and...
Source: Journal of Peptide Science - March 31, 2016 Category: Biochemistry Authors: Erik C. B. Johnson, Jennifer D. Lanning, Stephen C. Meredith Tags: Special Issue Article Source Type: research
A backbone amide protecting group for overcoming difficult sequences and suppressing aspartimide formation
A backbone amide bond protecting group, 2‐hydroxy‐4‐methoxy‐5‐nitrobenzyl (Hmnb), improved the synthesis of aggregation and aspartimide‐prone peptides. Introduction of Hmnb is automated and carried out during peptide assembly by addition of 4‐methoxy‐5‐nitrosalicylaldehyde to the peptidyl‐resin and on‐resin reduction to the secondary amine. Acylation of the hindered secondary amine is aided by the formation of an internal nitrophenol ester that undergoes a favourable O,N intramolecular acyl transfer. This activated ester participates in the coupling and generally gives complete reaction with standard ...
Source: Journal of Peptide Science - March 31, 2016 Category: Biochemistry Authors: Abu‐Baker M. Abdel‐Aal, George Papageorgiou, Richard Raz, Martin Quibell, Fabienne Burlina, John Offer Tags: Special Issue Article Source Type: research
Probing the structure–activity relationship of endogenous histone deacetylase complexes with immobilized peptide‐inhibitors
Abstract
Histone deacetylases (HDACs) are key regulators of numerous cellular proteins by removing acetylation marks from modified lysine residues. Peptide‐based HDAC probes containing α‐aminosuberic acid ω‐hydroxamate have been established as useful tools for investigating substrate selectivity and composition of endogenous HDAC complexes in cellular lysates. Here we report a structure–activity study of potential HDAC‐probes containing derivatives of the hydroxamate moieties. While most of these probes did not recruit significant amounts of endogenous HDACs from cellular lysates, peptides containing Nε‐acet...
Source: Journal of Peptide Science - March 31, 2016 Category: Biochemistry Authors: Julia Sindlinger, Jan Bierlmeier, Lydia‐Christina Geiger, Katharina Kramer, Iris Finkemeier, Dirk Schwarzer Tags: Special Issue Article Source Type: research
Dimerization effects on coacervation property of an elastin‐derived synthetic peptide (FPGVG)5
Elastin, a core protein of the elastic fibers, exhibits the coacervation (temperature‐dependent reversible association/dissociation) under physiological conditions. Because of this characteristic, elastin and elastin‐derived peptides have been considered to be useful as base materials for developing various biomedical products, skin substitutes, synthetic vascular grafts, and drug delivery systems. Although elastin‐derived polypeptide (Val‐Pro‐Gly‐Val‐Gly)n also has been known to demonstrate coacervation property, a sufficiently high (VPGVG)n repetition number (n > 40) is required for coacervation. In ...
Source: Journal of Peptide Science - March 28, 2016 Category: Biochemistry Authors: Keitaro Suyama, Suguru Taniguchi, Daiki Tatsubo, Iori Maeda, Takeru Nose Tags: Research Article Source Type: research
Synthesis and conformational analysis of an expanded cyclic ketoxime‐hexapeptide
In this work the synthesis of a linear hexapeptide with a hydroxylamine functionality at the N‐terminus and a ketone instead of the carboxylic acid at the C‐terminus is described. Cyclization by ketoxime formation yields the 19‐membered ring‐expanded cyclic hexapeptide cyclo[Goly‐Val‐Ala‐Pro‐Leu‐Kly] which adopts a main conformer with two intramolecular hydrogen bonds. The hydrolytic stability of a ketoxime lies between the inert amide and the labile imine. The substitution of an amide bond for an iminium bond transforms the irreversible macrocyclization into a reversible process, but macrocyclic imines a...
Source: Journal of Peptide Science - March 28, 2016 Category: Biochemistry Authors: Matthias Lamping, Yvonne Grell, Armin Geyer Tags: Research Article Source Type: research
Synthesis, binding affinities and metabolic stability of dimeric dermorphin analogs modified with β3‐homo‐amino acids
In this study, proteinogenic amino acids residues of dimeric dermorphin pentapeptides were replaced by the corresponding β3‐homo‐amino acids. The potency and selectivity of hybrid α/β dimeric dermorphin pentapeptides were evaluated by competetive receptor binding assay in the rat brain using [3H]DAMGO (a μ ligand) and [3H]DELT (a δ ligand). Tha analog containing β3‐homo‐Tyr in place of Tyr (Tyr‐d‐Ala‐Phe‐Gly‐β3‐homo‐Tyr‐NH‐)2 showed good μ receptor affinity and selectivity (IC50 = 0.302, IC50 ratio μ/δ = 68) and enzymatic stability in human plasma. Copyright © 2016 European Pept...
Source: Journal of Peptide Science - March 28, 2016 Category: Biochemistry Authors: Oliwia Frączak, Anika Lasota, Dagmara Tymecka, Piotr Kosson, Adriana Muchowska, Aleksandra Misicka, Aleksandra Olma Tags: Research Article Source Type: research
