Search results for: Zbigniew Szewczuk

Items from 1 to 20 out of 81 results

article

SOD-Like Activity of Copper(II) Containing Metallopeptides Branched By 2,3-Diaminopropionic Acid: What the N-Termini Elevate, the C-Terminus Ruins

Łukasz Szyrwiel, Mari Shimura, Bartosz Setner, Zbigniew Szewczuk, more

International Journal of Peptide Research and Therapeutics > 2019 > 25 > 2 > 711-717

Relations between structural modifiactions and SOD-like activity of four branched Cu^II-metallopeptides based on l-2,3-diaminopropionic acid are reported. The IC₅₀ values (McCord–Fridovich method) illustrate that enhanced SOD-like activity is warranted by exclusive N-terminal His localization that surmounts the driving force by the Cu^II/I formal potential.

article

Quaternary ammonium isobaric tag for a relative and absolute quantification of peptides

Bartosz Setner, Piotr Stefanowicz, Zbigniew Szewczuk

Journal of Mass Spectrometry > 53 > 2 > ii - ii

In the ongoing quest to develop improved quantitative approaches for complex mixtures of proteins, this month Setner and colleagues describe a strategy that combines an isobaric tag for relative and absolute quantification with the incorporation of a quaternary ammonium group to increase ionization efficiency. This strategy ‐ they call QAS‐iTRAQ 2‐plex ‐ can be adopted for both relative and absolute...

article

Quaternary ammonium isobaric tag for a relative and absolute quantification of peptides

Bartosz Setner, Piotr Stefanowicz, Zbigniew Szewczuk

Journal of Mass Spectrometry > 53 > 2 > 115 - 123

Isobaric labeling quantification of peptides has become a method of choice for mass spectrometry‐based proteomics studies. However, despite of wide variety of commercially available isobaric tags, none of the currently available methods offers significant improvement of sensitivity of detection during MS experiment. Recently, many strategies were applied to increase the ionization efficiency of peptides...

article

New ionization tags based on the structure of the 5-azoniaspiro[4.4]nonyl tag for a sensitive peptide sequencing by mass spectrometry

Bartosz Setner, Zbigniew Szewczuk

Analytical and Bioanalytical Chemistry > 2018 > 410 > 4 > 1311-1321

Quaternary ammonium salts (QAS), both linear and bicyclic, are often utilized to improve the mass spectrometry (MS) analysis of peptides by fixing a permanent positive charge on the analyzed molecule. However, during collision-induced dissociation (CID) experiments, QAS undergo unwanted side reactions—Hofmann elimination as well as a tertiary amine loss— rendering the data interpretation complicated...

article

Preparation of novel deuterated cyclosporin A standards for quantitative LC‐MS analysis

Remigiusz Bąchor, Alicja Kluczyk, Piotr Stefanowicz, Zbigniew Szewczuk

Journal of Mass Spectrometry > 52 > 12 > 817 - 822

The investigation on the synthesis of α‐C deuterated analogues of cyclosporin A (CsA) in N‐methylated amino acid residues was performed. The reaction based on our previous report (Bachor et al 2014 J Mass Spectrom 49, 43–49) proceeds in the presence of bases like TBD or MTBD at pH 13.4. The obtained results suggest the possibility of introduction of 3 deuterons, 2 at the α‐C of sarcosine, and 1 at...

article

The 5-azoniaspiro[4.4]nonyl group for improved MS peptide analysis: A novel non-fragmenting ionization tag for mass spectrometric sensitive sequencing of peptides

Bartosz Setner, Magdalena Rudowska, Alicja Kluczyk, Piotr Stefanowicz, more

Analytica Chimica Acta > 2017 > 986 > C > 71-81

A novel class of ionization tags, based on 5-azoniaspiro[4.4]nonyl (ASN⁺) scaffold were designed for improved analysis of peptides by electrospray tandem mass spectrometry (ESI-MS/MS). A new labeling agent, 1-{[3-oxo-3-(pentafluorophenoxy)propyl]carbamoyl}-5-azoniaspiro[4.4]nonane, was developed to react with amine and/or thiol group-containing peptides. The ionization efficiency of peptides resulting...

article

Complex formation equilibria of Cu2+ and Zn2+ with Irbesartan and Losartan

Joanna Izabela Lachowicz, Valeria Marina Nurchi, Guido Crisponi, Maria de Guadalupe Jaraquemada-Pelaez, more

European Journal of Pharmaceutical Sciences > 2017 > 97 > C > 158-169

We conducted a thorough study of Cu²⁺ complex formation equilibria with Irbesartan and Losartan, the two primary drugs for the cure of cardiovascular diseases, with the aim of recognising if these drugs could exert a chelating action towards Cu²⁺. We used different complementary techniques to gain a clear picture of the involved protonation and complexation equilibria. The low solubility in water...

article

Synthesis and mass spectrometry analysis of quaternary cryptando‐peptidic conjugates

Remigiusz Bąchor, Alicja Kluczyk, Piotr Stefanowicz, Zbigniew Szewczuk

Journal of Peptide Science > 21 > 12 > 879 - 886

The bicyclic amines in the form of cryptands, the crown ether analogs, were used in the synthesis of cryptando‐peptidic conjugates with simultaneous formation of quaternary ammonium nitrogen moiety. A series of model cryptando‐peptidic conjugates at the peptide N‐terminus was efficiently prepared by the standard Fmoc solid phase synthesis. Tandem mass spectrometric analysis of the obtained conjugates...

article

Convenient preparation of deuterium‐labeled analogs of peptides containing N‐substituted glycines for a stable isotope dilution LC‐MS quantitative analysis

Remigiusz Bąchor, Dawid Dębowski, Anna Łęgowska, Piotr Stefanowicz, more

Journal of Peptide Science > 21 > 11 > 819 - 825

N‐substituted glycines constitute mimics of natural amino acids that are of great interest in the peptide‐based drug development. Peptoids‐oligo(N‐substituted glycines) have been recently demonstrated to be highly active peptidomimetics in biological systems, resistant to proteolytic degradation. We developed a method of the deuterium labeling of peptidomimetics containing N‐substituted glycine residues...

article

Metal coordination and tyrosinase inhibition studies with Kojic-βAla-Kojic

Joanna Izabela Lachowicz, Valeria Marina Nurchi, Guido Crisponi, Maria de Guadalupe Jaraquemada Pelaez, more

Journal of Inorganic Biochemistry > 2015 > 151 > C > 36-43

Kojic acid is a natural antifungal and antibacterial agent that has been extensively studied for its tyrosinase inhibitory and metal coordination properties. Tyrosinase is a metalloenzyme with two copper ions in the active site. It is widely accepted that the tyrosinase inhibitory activity of kojic acid is related to its ability to coordinate metals. Over the past five years, we have used kojic acid...

article

N‐terminal guanidinylation of the cyclic 1,4‐ureido‐deltorphin analogues: the synthesis, receptor binding studies, and resistance to proteolytic digestion

Krzysztof Bańkowski, Olga M. Michalak, Anna Leśniak, Katarzyna E. Filip, more

Journal of Peptide Science > 21 > 6 > 467 - 475

The synthesis of a series of N‐guanidinylated cyclic ureidopeptides, analogues of 1,4‐ureido‐deltorphin/dermorphine tetrapeptide is described. The δ‐ and μ‐opioid receptor affinity of new guanidinylated analogues and their non‐guanidinylated precursors was determined by the displacement radioligand binding experiments. Our results indicate that the guanidinylation of cyclic 1,4‐ureidodeltorphin peptide...

article

A synthesis of new, bi-labeled peptides for quantitative proteomics

Maciej Modzel, Halina Płóciennik, Martyna Kielmas, Zbigniew Szewczuk, more

Journal of Proteomics > 2015 > 115 > C > 1-7

Isotopically labeled peptides are often used in proteomics as internal reference allowing quantification of peptides by isotopic dilution method. Although the synthesis of peptides labeled with stable isotopes is relatively simple, there are several factors limiting application of these standards in proteomic research: cost of labeled derivatives of amino acids, time needed to obtain labeled peptide...

article

Site-selective solid phase synthesis of carbonylated peptides

Mateusz Waliczek, Monika Kijewska, Piotr Stefanowicz, Zbigniew Szewczuk

Amino Acids > 2015 > 47 > 7 > 1353-1365

The aim of our research was to design an efficient method for the solid phase synthesis of carbonylated peptides. For this purpose, we designed and synthesized a fully protected derivative Fmoc-amino(2,5,5-trimetyhyl-1,3-dioxolan-2-yl)acetic acid (Fmoc-Atda-OH) of a novel unnatural amino acid (Thr(O)-2-amino-3-oxo-butanoic acid). To obtain the mentioned derivative, two synthetic strategies were investigated...

article

Multifunctional peptides derived from an egg yolk protein hydrolysate: isolation and characterization

Aleksandra Zambrowicz, Marta Pokora, Bartosz Setner, Anna Dąbrowska, more

Amino Acids > 2015 > 47 > 2 > 369-380

An egg yolk protein by-product following ethanol extraction of phospholipids (YP) was hydrolyzed with pepsin to produce and identify novel peptides that revealed antioxidant, ACE inhibitory and antidiabetic (α-glucosidase and DPP-IV inhibitory) activities. The peptic hydrolysate of YP was fractionated by ion-exchange chromatography and reversed-phase high-pressure liquid chromatography. Isolated peptides...

article

Comparison of modification sites in glycated crystallin in vitro and in vivo

Martyna Kielmas, Monika Kijewska, Alicja Kluczyk, Jolanta Oficjalska, more

Analytical and Bioanalytical Chemistry > 2015 > 407 > 9 > 2557-2567

Glycation of α-crystallin is responsible for age- and diabetic-related cataracts, which are the main cause of blindness worldwide. We optimized the method of identification of lysine residues prone to glycation using the combination of LC-MS, isotopic labeling, and modified synthetic peptide standards with the glycated lysine derivative (Fmoc-Lys( i , i -Fru,Boc)-OH)...

article

Facile synthesis of deuterium-labeled denatonium cation and its application in the quantitative analysis of Bitrex by liquid chromatography-mass spectrometry

Remigiusz Bąchor, Alicja Kluczyk, Piotr Stefanowicz, Zbigniew Szewczuk

Analytical and Bioanalytical Chemistry > 2015 > 407 > 21 > 6557-6561

Quantitative analysis by liquid chromatography-mass spectrometry (LC-MS) is frequently based on the application of isotopically labeled standards which usually have to be specially synthesized. Although the synthesis of deuterated isotopologues is relatively inexpensive, they are not considered as good internal standards due to the possible deuterium effect on the retention time during LC-MS...

article

A new bis-3-hydroxy-4-pyrone as a potential therapeutic iron chelating agent. Effect of connecting and side chains on the complex structures and metal ion selectivity

Valeria M. Nurchi, Guido Crisponi, Massimiliano Arca, Miriam Crespo-Alonso, more

Journal of Inorganic Biochemistry > 2014 > 141 > C > 132-143

This work reports the synthesis, characterization and study of complex formation equilibria of the new ligand 6,6′-(2-(diethylamino)ethylazanediyl)bis(methylene)bis(5-hydroxy-2-hydroxymethyl-4H-pyran-4-one) with Fe^III, Al^III, Cu^II and Zn^II. On the basis of previous encouraging results with tetradentate bis-kojic acid chelators, this ligand was designed to improve the pharmacokinetic properties: increase...

article

Microwave‐assisted ¹⁸O labeling of Fmoc‐protected amino acids

Maciej Modzel, Halina Płóciennik, Alicja Kluczyk, Piotr Stefanowicz, more

Journal of Peptide Science > 20 > 11 > 896 - 900

Recently, there has been an increased interest in isotopical labeling of peptides. Although there are several techniques allowing for a complete labeling of all carboxyl groups in peptides, regioselective labeling would be beneficial in many situations. Such labeling requires the use of ¹⁸O‐labeled Fmoc amino acids. We have designed a method for such labeling that is an improvement on a technique...

article

Egg-yolk protein by-product as a source of ACE-inhibitory peptides obtained with using unconventional proteinase from Asian pumpkin (Cucurbita ficifolia)

Ewelina Eckert, Aleksandra Zambrowicz, Marta Pokora, Bartosz Setner, more

Journal of Proteomics > 2014 > 110 > Complete > 107-116

In the present study angiotensin I-converting enzyme (ACE) inhibitory peptides were isolated from egg-yolk protein preparation (YP). Enzymatic hydrolysis conducted using unconventional enzyme from Cucurbita ficifolia (dose: 1000U/mg of hydrolyzed YP (E/S (w/w)=1:7.52)) was employed to obtain protein hydrolysates. The 4-h hydrolysate exhibited a significant (IC ₅₀ =482.5μg/mL) ACE inhibitory...

article

Peptides derivatized with bicyclic quaternary ammonium ionization tags. Sequencing via tandem mass spectrometry

Bartosz Setner, Magdalena Rudowska, Ewelina Klem, Marek Cebrat, more

Journal of Mass Spectrometry > 49 > 10 > 995 - 1001

Improving the sensitivity of detection and fragmentation of peptides to provide reliable sequencing of peptides is an important goal of mass spectrometric analysis. Peptides derivatized by bicyclic quaternary ammonium ionization tags: 1‐azabicyclo[2.2.2]octane (ABCO) or 1,4‐diazabicyclo[2.2.2]octane (DABCO), are characterized by an increased detection sensitivity in electrospray ionization mass spectrometry...

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Keywords

MASS SPECTROMETRY (10)
QUATERNARY AMMONIUM SALTS (8)
DERIVATIZATION OF PEPTIDES (7)
GLYCATION (7)
AMADORI PRODUCTS (6)
HISTOCOMPATIBILITY ANTIGEN (5)
IMMUNOSUPPRESSORS (5)
PEPTIDE SEQUENCING (5)
SOLID PHASE SYNTHESIS (5)
IONIZATION TAG (4)
KOJIC ACID (4)
SYNTHESIS (4)
THYMOPENTIN ANALOGS (4)
2,3:4,5-DI-O-ISOPROPYLIDENE-Β-D-ARABINO-HEXOS-2-ULO-2,6-PYRANOSE (3)
AMADORI REARRANGEMENT (3)
ESI‐MS/MS (3)
HDX (3)
HDX OF PEPTIDES (3)
HLA-DQ (3)
ISOTOPIC LABELING (3)
PEPTIDE SYNTHESIS (3)
QUANTITATIVE ANALYSIS (3)
RGD-SEQUENCE (3)
SOLID PHASE PEPTIDE SYNTHESIS (3)
SOLUTION EQUILIBRIA (3)
X-RAY STUDIES (3)
4-AMINO-3-NITROPHENYLALANINE (2)
CD4 (2)
CHARGE-TAGGED PEPTIDES (2)
CHEMICAL SYNTHESIS (2)
CYCLIC OPIOID PEPTIDES (2)
DERMORPHIN/DELTORPHIN ANALOGUES (2)
ESI-MS (2)
HYDROGEN DEUTERIUM EXCHANGE (2)
HYDROXYPYRONES (2)
ISOTOPE DILUTION (2)
LINKER LENGTH (2)
MHC CLASS-II (2)
MHC FRAGMENTS (2)
MRM (2)
NMR (2)
NON-ENZYMATIC GLYCATION (2)
OBOC (2)
QUANTITATIVE PROTEOMICS (2)
SARCOSINE (2)
SOLID-PHASE PEPTIDE SYNTHESIS (2)
STABILITY TO PROTEOLYTIC ENZYMES (2)
STABLE ISOTOPES (2)
UBIQUITIN FRAGMENTS (2)
UNNATURAL AMINO ACIDS (2)
X-RAY STRUCTURE (2)
13C (1)
18O (1)
2H (1)
18O (1)
18O LABELING (1)
ABCO (1)
ACE INHIBITORY ACTIVITY (1)
ADVANCED GLYCATION END PRODUCTS (1)
AL(III) (1)
ALLOGRAFT SKIN SURVIVAL (1)
ALUMINIUM RELATED DISEASES (1)
AMADORI (1)
ANGIOTENSIN I-CONVERTING ENZYME INHIBITORY ACTIVITY (1)
ANTIBODY PRODUCTION (1)
ANTIDIABETIC (1)
ANTINOCICEPTIVE EFFECT (1)
ANTIOXIDANT (1)
ASSOCIATION CONSTANT (1)
BENSERAZIDE (1)
BENZIMIDAZOLES (1)
BETAINE (1)
BINDING TO OPIOID RECEPTORS (1)
BIOMIMETICS (1)
BITREX (1)
BRANCHED PEPTIDES (1)
BRIDGED ANALOG (1)
CARBONYLATED PEPTIDES (1)
CARBONYLATION (1)
CHARGE-REMOTE FRAGMENTATION (1)
CHARGE‐REMOTE FRAGMENTATION (1)
CHELATION THERAPY (1)
CHMG1A (1)
CLEAVAGE (1)
COAGULATION PROTEINASE (1)
COMBINATORIAL SYNTHESIS (1)
COMPLEX FORMATION EQUILIBRIA (1)
COPPER (1)
COPPER(II) COMPLEXES (1)
COPPER(II)-CATALYZED OXIDATION (1)
CRYPTANDS (1)
CRYPTIDES (1)
CRYSTAL STRUCTURES (1)
CRYSTALLIN (1)
CUCURBITA FICIFOLIA (1)
CYCLIC PEPTIDE ANALOG (1)
CYCLOSPORIN A (1)
CYCLOSPORINE (1)
DABCO (1)
DETECTION SENSITIVITY (1)
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Elsevier (32)
Springer (19)
Wiley (18)
PSJD (8)
ACS (4)

Journal

Journal of Peptide Science (7)
Acta Biochimica Polonica (6)
Journal of Inorganic Biochemistry (6)
Journal of Mass Spectrometry (6)
Amino Acids (5)
Analytical and Bioanalytical Chemistry (4)
Journal of The American Society for Mass Spectrometry (4)
Peptides (4)
Analytical Biochemistry (3)
Molecular Immunology (3)
International Journal of Peptide Research and Therapeutics (2)
Journal of Proteomics (2)
Molecular Diversity (2)
Open Chemistry (2)
Rapid Communications in Mass Spectrometry (2)
Tetrahedron Letters (2)
Analytica Chimica Acta (1)
Archives of Biochemistry and Biophysics (1)
Biochemical and Biophysical Research Communications (1)
Biochemistry (1)
Biochimica et Biophysica Acta (BBA)/Protein Structure and Molecular Enzymology (1)
Bioconjugate Chemistry (1)
Biomacromolecules (1)
Bioorganic Chemistry (1)
Carbohydrate Research (1)
Central European Journal of Chemistry (1)
European Journal of Medicinal Chemistry (1)
European Journal of Pharmaceutical Sciences (1)
Inorganic Chemistry (1)
International Journal of Mass Spectrometry (1)
Journal of Molecular Biology (1)
Journal of Molecular Recognition (1)
Journal of Pharmaceutical and Biomedical Analysis (1)
Molecular and Cellular Biochemistry (1)
Polyhedron (1)
Proteins: Structure, Function, and Bioinformatics (1)
The FEBS Journal (1)
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INFONA - science communication portal

Search results for: Zbigniew Szewczuk

SOD-Like Activity of Copper(II) Containing Metallopeptides Branched By 2,3-Diaminopropionic Acid: What the N-Termini Elevate, the C-Terminus Ruins

Quaternary ammonium isobaric tag for a relative and absolute quantification of peptides

Quaternary ammonium isobaric tag for a relative and absolute quantification of peptides

New ionization tags based on the structure of the 5-azoniaspiro[4.4]nonyl tag for a sensitive peptide sequencing by mass spectrometry

Preparation of novel deuterated cyclosporin A standards for quantitative LC‐MS analysis

The 5-azoniaspiro[4.4]nonyl group for improved MS peptide analysis: A novel non-fragmenting ionization tag for mass spectrometric sensitive sequencing of peptides

Complex formation equilibria of Cu2+ and Zn2+ with Irbesartan and Losartan

Synthesis and mass spectrometry analysis of quaternary cryptando‐peptidic conjugates

Convenient preparation of deuterium‐labeled analogs of peptides containing N‐substituted glycines for a stable isotope dilution LC‐MS quantitative analysis

Metal coordination and tyrosinase inhibition studies with Kojic-βAla-Kojic

N‐terminal guanidinylation of the cyclic 1,4‐ureido‐deltorphin analogues: the synthesis, receptor binding studies, and resistance to proteolytic digestion

A synthesis of new, bi-labeled peptides for quantitative proteomics

Site-selective solid phase synthesis of carbonylated peptides

Multifunctional peptides derived from an egg yolk protein hydrolysate: isolation and characterization

Comparison of modification sites in glycated crystallin in vitro and in vivo

Facile synthesis of deuterium-labeled denatonium cation and its application in the quantitative analysis of Bitrex by liquid chromatography-mass spectrometry

A new bis-3-hydroxy-4-pyrone as a potential therapeutic iron chelating agent. Effect of connecting and side chains on the complex structures and metal ion selectivity

Microwave‐assisted ¹⁸O labeling of Fmoc‐protected amino acids

Egg-yolk protein by-product as a source of ACE-inhibitory peptides obtained with using unconventional proteinase from Asian pumpkin (Cucurbita ficifolia)

Peptides derivatized with bicyclic quaternary ammonium ionization tags. Sequencing via tandem mass spectrometry

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