Site-selective solid phase synthesis of carbonylated peptides

Waliczek, Mateusz; Kijewska, Monika; Stefanowicz, Piotr; Szewczuk, Zbigniew

doi:10.1007/s00726-015-1967-4

Cited by 5 publications

(5 citation statements)

References 29 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The ESI-MS spectrum revealed two equal intensity signals at m/z 465.2468 and 467.2486, corresponding to the reduced α-ketoacyl group bearing 16 O and 18 O atoms, respectively. This result is similar to that obtained previously for a product of threonine oxidation 33 and confirms the presence of a carbonyl group susceptible to isotopic exchange of oxygen atoms.…”

supporting

confidence: 91%

High-Temperature, Solid-Phase Reaction of α-Amino Groups in Peptides with Lactose and Glucose: An Alternative Mechanism Leading to an α-Ketoacyl Derivative

Kijewska

Zawadzka

Stefanowicz

2023

J. Agric. Food Chem.

Self Cite

View full text Add to dashboard Cite

The reaction of proteins with reducing sugars results in the formation of Amadori products, which involves the Nterminal group and/or ε-amino group of the lysine side chain. However, less attention has been given to the reactivity of the Nterminus of a peptide chain under similar conditions. In our work, we focused on the reaction of the α-amino group of peptides in the presence of a reducing sugar, specifically lactose. We optimized the reaction conditions of model peptides with lactose in the solid phase and showed that temperatures above 120 °C lead to the deamination of the N-terminal amino acid moiety, ultimately resulting in α-ketoacids. We carried out detailed studies to confirm the structure of the deaminated product using analytical methods such as ESI-MS and LC−MS/MS, as well as chemical methods that involved the reduction of the carbonyl group combined with isotopic exchange and the reactivity of the carbonyl group with the hydroxylamine derivative. The structure of the reaction product was also confirmed by chemical synthesis. We suggested plausible mechanisms for the formation of the deaminated product and considered the probable path of its formation. Our aim was to determine whether the reaction proceeds according to the Streckerbased mechanism and direct imine isomerization by carrying out reactions of model peptides in the presence of lactose under aerobic and anaerobic conditions and comparing the results obtained. KEYWORDS: LC−MS/MS analysis, lactosylated peptides, α-ketoacid derivatives, deamination catalyzed by a reducing sugar ■ HIGHLIGHTS• LC−MS/MS analysis of lactosylated peptides.• Deamination of the N-terminal amino acid by a reducing sugar. • Chemoselective reaction of the hydroxylamine derivative with the deamination product.

show abstract

supporting

confidence: 91%

High-Temperature, Solid-Phase Reaction of α-Amino Groups in Peptides with Lactose and Glucose: An Alternative Mechanism Leading to an α-Ketoacyl Derivative

Kijewska

Zawadzka

Stefanowicz

2023

J. Agric. Food Chem.

Self Cite

View full text Add to dashboard Cite

show abstract

“…The same phenomenon was observed in our previous investigations during the analysis of peptides comprising oxidized threonine, an unnatural amino acid. Previous LC-MS analysis confirmed racemization of carbonylated peptides 13 . Additionally, we performed fragmentation experiments for signals at m/z 482.26, 525.27, and 335.20 to confirm the structure of the obtained modified products ( Figs S8 , S9 and S10 ).…”

Section: Resultsmentioning

confidence: 80%

“…Studies on the detection and quantification of post-translationaly modified peptides (e.g., carbonylated or glycated) require defined, analytically pure standards of modified peptides 11 , 12 . Recently, we performed the synthesis of carbonylated and glycated model peptides on a solid support using designed and synthesised building blocks 13 , 14 . These compounds were tested to confirm the identity of a glycated crystalline fragment found in biological material 11 , 14 .…”

Section: Introductionmentioning

confidence: 99%

“…These compounds were tested to confirm the identity of a glycated crystalline fragment found in biological material 11 , 14 . Our synthesized building block Fmoc-amino(2,5,5-trimetyhyl-1,3-dioxolan-2-yl)acetic acid (Fmoc-Atda-OH) 13 allows the synthesis of peptides containing the D,L-Thr(O) residue, which may be used as models of oxidatively modified peptides that occur in biological systems and are related to many diseases 15 , 16 .…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Solid-phase synthesis of peptides containing aminoadipic semialdehyde moiety and their cyclisations

Kijewska

Waliczek

Cal

et al. 2018

Sci Rep

Self Cite

View full text Add to dashboard Cite

Pathological levels of oxidative stress (OS) have been implicated in many diseases including diabetes mellitus, neurodegenerative diseases, inflammatory diseases, atherosclerosis, and cancer. Studies of oxidative stress are however complicated by the low concentration of oxidation products. To resolve this problem, we tested a new derivative of aminoadipic semialdehyde (Fmoc-Aea-OH) in the solid-phase synthesis of carbonylated peptides. We prepared a series of peptides with free and acetylated N-terminal amino groups using the Fmoc-Aea-OH reagent. LC-MS, ESI-MS, and MS/MS spectra confirmed the sequences of the modified peptides, although the LC-MS and ESI-MS spectra were dominated by signals corresponding to dehydration products. NMR studies of acetylated products revealed that the dominant product formed in this reaction contains a 1,2,3,4-tetrahydropyridine-2-carboxylic acid residue. Another side reaction in this system was the cleavage of the amide bond between the Aea residue and the amino acid moiety preceding it resulting in the formation of a side product with a six-membered ring at the N-terminus (2,3,4,5-tetrahydropyridine-2-carboxylic acid residue). We found that, depending on the peptide sequence, one of those side products is predominant. Our work suggests new methods for the solid-state synthesis of peptides containing unnatural amino acids.

show abstract

“…By substituting the amide bond by an oxime linkage, the cyclic peptides become more stable and isolable, especially in the case of ketoximes . Several approaches have been made to synthesize amino acid side chain aldehydes/ketones for the ligation or cyclization with hydroxylamines .…”

Section: Introductionmentioning

confidence: 99%

Synthesis and conformational analysis of an expanded cyclic ketoxime-hexapeptide

2016

View full text Add to dashboard Cite

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 are difficult to isolate because they are prone to hydrolysis. The enhanced chemical stability of the ketoxime justifies its application in ligation protocols. The detailed NMR analysis of a ketoxime linkage presented here identifies its local conformational preferences in a constrained peptide environment.

show abstract

Site-selective solid phase synthesis of carbonylated peptides

Cited by 5 publications

References 29 publications

High-Temperature, Solid-Phase Reaction of α-Amino Groups in Peptides with Lactose and Glucose: An Alternative Mechanism Leading to an α-Ketoacyl Derivative

High-Temperature, Solid-Phase Reaction of α-Amino Groups in Peptides with Lactose and Glucose: An Alternative Mechanism Leading to an α-Ketoacyl Derivative

Solid-phase synthesis of peptides containing aminoadipic semialdehyde moiety and their cyclisations

Synthesis and conformational analysis of an expanded cyclic ketoxime-hexapeptide

Contact Info

Product

Resources

About