Determination of counter‐ions in synthetic peptides by ion chromatography, capillary isotachophoresis and capillary electrophoresis

Mrozik, Wojciech; Markowska, Aleksandra; Guzik, Łukasz; Kraska, Bartlomiej; Kamysz, Wojciech

doi:10.1002/psc.1436

Cited by 8 publications

(8 citation statements)

References 24 publications

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“…According to LC–MS no peptide degradation was observed. Interestingly, similar results were obtained for other peptides (pexiganan and temporin A) in previous works (Mrozik et al 2012 ).…”

Section: Resultssupporting

confidence: 90%

Citropin 1.1 Trifluoroacetate to Chloride Counter-Ion Exchange in HCl-Saturated Organic Solutions: An Alternative Approach

Sikora

Neubauer

Jaśkiewicz

et al. 2017

Int J Pept Res Ther

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In view of the increasing interest in peptides in various market sectors, a stronger emphasis on topics related to their production has been seen. Fmoc-based solid phase peptide synthesis, although being fast and efficient, provides final products with significant amounts of trifluoroacetate ions in the form of either a counter-ion or an unbound impurity. Because of the proven toxicity towards cells and peptide activity inhibition, ion exchange to more biocompatible one is purposeful. Additionally, as most of the currently used counter-ion exchange techniques are time-consuming and burdened by peptide yield reduction risk, development of a new approach is still a sensible solution. In this study, we examined the potential of peptide counter-ion exchange using non-aqueous organic solvents saturated with HCl. Counter-ion exchange of a model peptide, citropin 1.1 (GLFDVIKKVASVIGGL-NH2), for each solvent was conducted through incubation with subsequent evaporation under reduced pressure, dissolution in water and lyophilization. Each exchange was performed four times and compared to a reference method—lyophilization of the peptide from an 0.1 M HCl solution. The results showed superior counter-ion exchange efficiency for most of the organic solutions in relation to the reference method. Moreover, HCl-saturated acetonitrile and tert-butanol provided a satisfying exchange level after just one repetition. Thus, those two organic solvents can be potentially introduced into routine peptide counter-ion exchange.

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Section: Resultssupporting

confidence: 90%

Citropin 1.1 Trifluoroacetate to Chloride Counter-Ion Exchange in HCl-Saturated Organic Solutions: An Alternative Approach

Sikora

Neubauer

Jaśkiewicz

et al. 2017

Int J Pept Res Ther

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“…The crude products were purified and analyzed by reversed-phase high-performance liquid chromatography (RP-HPLC) in an acetonitrile-water (Sigma Aldrich, Steinheim, Germany) gradient containing 0.1% TFA. The identity of the peptides was confirmed by matrix-assisted laser desorption/ionization time of flight mass spectrometry (MALDI-TOF) and the counter-ion was determined by ion chromatography [71,72]. MS and HPLC analysis are included in Supplementary Materials.…”

Section: Methodsmentioning

confidence: 99%

Influence of Amphibian Antimicrobial Peptides and Short Lipopeptides on Bacterial Biofilms Formed on Contact Lenses

et al. 2016

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The widespread use of contact lenses is associated with several complications, including ocular biofilm-related infections. They are very difficult to manage with standard antimicrobial therapies, because bacterial growth in a biofilm is associated with an increased antibiotic resistance. The principal aim of this study was to evaluate the efficacy of antimicrobial peptides (AMPs) in eradication of bacterial biofilms formed on commercially available contact lenses. AMPs were synthesized according to Fmoc/tBu chemistry using the solid-phase method. Minimum inhibitory concentration (MIC) and minimum biofilm eradication concentration (MBEC) of the compounds were determined. Anti-biofilm activity of the antimicrobial peptides determined at different temperatures (25 °C and 37 °C) were compared with the effectiveness of commercially available contact lens solutions. All of the tested compounds exhibited stronger anti-biofilm properties as compared to those of the tested lens solutions. The strongest activity of AMPs was noticed against Gram-positive strains at a temperature of 25 °C. Conclusions: The results of our experiments encourage us toward further studies on AMPs and their potential application in the prophylaxis of contact lens-related eye infections.

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“…Preparative reversed‐phase HPLC was performed on Tosoh TSKgel ODS‐120T column (21.5 mm × 300 mm) (Tosoh, Tokyo, Japan) using the same solvent system (gradient 0.5%/min, flow rate 7 ml/min). Purified compounds (purity determined by HPLC >98%) were transformed into acetate salts by dissolving in 50% acetic acid, dilution, and lyophilization .…”

Section: Methodsmentioning

confidence: 99%

Dimeric analogs of immunosuppressive decapeptide fragment of ubiquitin

Kluczyk

Cydzik

Biernat

et al. 2012

Journal of Peptide Science

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Our previous studies revealed that ubiquitin and its decapeptide fragment with the LEDGRTLSDY sequence, located on the exposed molecule loop, strongly suppressed the immune response. This suggested that the loop may serve as a functional epitope of ubiquitin molecule and that a possible mechanism of biological action of the synthesized peptides is associated with interfering in interactions of ubiquitin with other molecules. Ubiquitin is known to exist in oligomeric forms, which can interact with various oligomeric receptors. We designed and synthesized new dimeric analogs of the ubiquitin fragment, to probe whether dimeric peptides may have higher affinity towards the ubiquitin receptors responsible for immunosuppression, which are believed to form oligomeric structures. Three dimerization strategies, N-terminus to N-terminus, C-terminus to C-terminus, and N-terminus to C-terminus (head-to-tail) via PEG derivatives were used to synthesize the dimeric peptides on solid support. In the course of our research, we developed a new and straightforward procedure of dimerization where α-amino groups of the C-terminal lysine residues of two peptide fragments were linked by PEG spacer directly on solid support. The effect of dimeric analogs on the immunological response was tested in the AFC in vitro experiment. The immunological tests showed that the head-to-tail dimerization caused a more profound increase in the biological activity than other tested dimerization methods. Our results suggest that such orientation of peptide components may correspond to orientation of the hypothetic ubiquitin receptors responsible for the immunomodulatory activity.

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Determination of counter‐ions in synthetic peptides by ion chromatography, capillary isotachophoresis and capillary electrophoresis

Cited by 8 publications

References 24 publications

Citropin 1.1 Trifluoroacetate to Chloride Counter-Ion Exchange in HCl-Saturated Organic Solutions: An Alternative Approach

Citropin 1.1 Trifluoroacetate to Chloride Counter-Ion Exchange in HCl-Saturated Organic Solutions: An Alternative Approach

Influence of Amphibian Antimicrobial Peptides and Short Lipopeptides on Bacterial Biofilms Formed on Contact Lenses

Dimeric analogs of immunosuppressive decapeptide fragment of ubiquitin

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