Peptide Hydrazides Research Articles

Synthesis of Highly-strained Cyclic Tetrapeptides via Peptide Hydrazide Based Ligation

A series of highly-strained cyclic tetrapeptides were efficiently synthesized via peptide hydrazide based ligation, reported by Liu et al. Upon mild oxidative activation, the peptide hydrazide was transformed into a highly active peptide azide intermediate and then in situ converted into a peptide 4-mercaptophenylacetic acid (MPAA) thiol ester, which under- went native chemical ligation (NCL)-mediated cyclization to afford the desired cyclic tetrapeptides. After radical desulfuriza- tion, the product with alanine residue at the ligation site can be obtained. Keywords chemical ligation; peptide hydrazide; cyclic tetrapeptide; radical desulfurization

Synthesis of Nesiritide via Ligation of Peptide Hydrazide

Nesiritide is an important class of peptide vasodilator. It plays a significant role in the maintenance homeostasis of cardiovascular and kidney. Nowadays, nesiritide is mainly obtained by biological methods including gene recombinant expression, which is relative time-consuming. In present work, the chemical synthesis of nesiritide was reported by using (solid-phase peptide synthesis) (SPPS) strategy combining with the ligation of peptide hydrazides with high yield and purity. Therefore, it was considered that the method presented here provided a convinced alternative for acquiring pharmaceutical peptide in a large scale.

Chemical synthesis of proteins using peptide hydrazides as thioester surrogates

This protocol provides a detailed procedure for the chemical synthesis of proteins through native chemical ligation of peptide hydrazides. The two crucial stages of this protocol are (i) the solid-phase synthesis of peptide hydrazides via Fmoc chemistry and (ii) the native chemical ligation of peptide hydrazides through in situ NaNO2 activation and thiolysis. This protocol may be of help in the synthesis of proteins that are not easily produced by recombinant technology and that include acid-sensitive modifications; it also does not involve the use of hazardous HF. The utility of the protocol is shown for the total synthesis of 140-aa-long α-synuclein, a protein that has an important role in the development of Parkinson's disease. The whole synthesis of the target protein α-synuclein in milligram scale takes ~30 working days.

New semi‐synthesis of ubiquitin C‐terminal conjugate with 7‐amino‐4‐methylcoumarin

The ligation of peptide hydrazides at a Gly site carrying a removal auxiliary was found to be an efficient process. This technology was successfully used for the synthesis of ubiquitin C-terminal conjugates. Recombinant Ub(1-75)-NHNH2 was prepared through the hydrozinolysis of the Ub(1-75)-intein fusion protein. It was ligated with a glycine derivative modified with an acid-sensitive thiol auxiliary. The final acid treatment produced the desired bioactive ubiquitin conjugates in practical quantities. Thus, the method described here extends the protocols of expressed protein ligation.

ChemInform Abstract: Chemical Methods for Peptide and Protein Production

AbstractReview: 102 refs.

Chemical synthesis of Ub-AMC via ligation of peptide hydrazides

The C-terminal conjugate of ubiquitin with 7-amino-4-methylcoumarin (Ub-AMC) is an important probe for fluorescence-based analysis of deubiquitinating enzyme (DUB) activity. It is important to develop more efficient methods for the preparation of Ub-AMC because the currently available technology is still expensive for scaled-up production. In the present work we report an efficient strategy for total chemical synthesis of Ub-AMC through ligation of peptide hydrazides. Three peptide segments are assembled via N-to-C sequential ligation and the resulting product is converted to Ub-AMC via TCEP-mediated desulfurization. The synthetic Ub-AMC is shown to have expected biological functions through the measurement of its DUB activity.

Chemical Methods for Peptide and Protein Production

Since the invention of solid phase synthetic methods by Merrifield in 1963, the number of research groups focusing on peptide synthesis has grown exponentially. However, the original step-by-step synthesis had limitations: the purity of the final product decreased with the number of coupling steps. After the development of Boc and Fmoc protecting groups, novel amino acid protecting groups and new techniques were introduced to provide high quality and quantity peptide products. Fragment condensation was a popular method for peptide production in the 1980s, but unfortunately the rate of racemization and reaction difficulties proved less than ideal. Kent and co-workers revolutionized peptide coupling by introducing the chemoselective reaction of unprotected peptides, called native chemical ligation. Subsequently, research has focused on the development of novel ligating techniques including the famous click reaction, ligation of peptide hydrazides, and the recently reported α-ketoacid-hydroxylamine ligations with 5-oxaproline. Several companies have been formed all over the world to prepare high quality Good Manufacturing Practice peptide products on a multi-kilogram scale. This review describes the advances in peptide chemistry including the variety of synthetic peptide methods currently available and the broad application of peptides in medicinal chemistry.

Label-free Quantitative Proteomics and N-Glycoproteomics Analysis of KRAS-activated Human Bronchial Epithelial Cells

Mutational activation of KRAS promotes various malignancies, including lung adenocarcinoma. Knowledge of the molecular targets mediating the downstream effects of activated KRAS is limited. Here, we provide the KRAS target proteins and N-glycoproteins using human bronchial epithelial cells with and without the expression of activated KRAS (KRAS(V12)). Using an OFFGEL peptide fractionation and hydrazide method combined with subsequent LTQ-Orbitrap analysis, we identified 5713 proteins and 608 N-glycosites on 317 proteins in human bronchial epithelial cells. Label-free quantitation of 3058 proteins (≥2 peptides; coefficient of variation (CV) ≤ 20%) and 297 N-glycoproteins (CV ≤ 20%) revealed the differential regulation of 23 proteins and 14 N-glycoproteins caused by activated KRAS, including 84% novel ones. An informatics-assisted IPA-Biomarker® filter analysis prioritized some of the differentially regulated proteins (ALDH3A1, CA2, CTSD, DST, EPHA2, and VIM) and N-glycoproteins (ALCAM, ITGA3, and TIMP-1) as cancer biomarkers. Further, integrated in silico analysis of microarray repository data of lung adenocarcinoma clinical samples and cell lines containing KRAS mutations showed positive mRNA fold changes (p < 0.05) for 61% of the KRAS-regulated proteins, including biomarker proteins, CA2 and CTSD. The most significant discovery of the integrated validation is the down-regulation of FABP5 and PDCD4. A few validated proteins, including tumor suppressor PDCD4, were further confirmed as KRAS targets by shRNA-based knockdown experiments. Finally, the studies on KRAS-regulated N-glycoproteins revealed structural alterations in the core N-glycans of SEMA4B in KRAS-activated human bronchial epithelial cells and functional role of N-glycosylation of TIMP-1 in the regulation of lung adenocarcinoma A549 cell invasion. Together, our study represents the largest proteome and N-glycoproteome data sets for HBECs, which we used to identify several novel potential targets of activated KRAS that may provide insights into KRAS-induced adenocarcinoma and have implications for both lung cancer therapy and diagnosis.

Convergent Chemical Synthesis of Proteins by Ligation of Peptide Hydrazides

Convergent Chemical Synthesis of Proteins by Ligation of Peptide Hydrazides

Convergent Chemical Synthesis of Proteins by Ligation of Peptide Hydrazides

Rasche Vereinigung: Eine allgemein anwendbare Strategie für die konvergente chemische Synthese von Proteinen aus Peptidsegmenten wurde entwickelt. Die Peptidhydrazid-Zwischenstufen können kostengünstig hergestellt werden, und die neue Strategie wurde zur Synthese des 142 Aminosäuren langen Modellproteins RpS25 aus sechs Peptidsegmenten eingesetzt. PG=Schutzgruppe. Detailed facts of importance to specialist readers are published as ”Supporting Information”. Such documents are peer-reviewed, but not copy-edited or typeset. They are made available as submitted by the authors. Please note: The publisher is not responsible for the content or functionality of any supporting information supplied by the authors. Any queries (other than missing content) should be directed to the corresponding author for the article.

Synthesis of Cyclic Peptides and Cyclic Proteins via Ligation of Peptide Hydrazides

Intramolecular ligation of peptide hydrazides is reported to occur readily, causing the lactamization of fully unprotected peptides in an epimerization-free manner. This method relies on the routine procedures of Fmoc solid-phase peptide synthesis. It can be used to prepare cyclic peptides and cyclic proteins under simpler, mild conditions at lower costs.

Synthesis of Cyclic Tetrapeptides via Ligation of Peptide Hydrazides

Synthesis of Cyclic Tetrapeptides via Ligation of Peptide Hydrazides

Three-Component Synthesis of Neoglycopeptides Using a Cu(II)-Triggered Aminolysis of Peptide Hydrazide Resin and an Azide–Alkyne Cycloaddition Sequence

Copper(II)-induced oxidative aminolysis of hydrazides generates Cu(I), the catalyst of the azide-alkyne cycloaddition. This feature was exploited to design a novel solid phase detaching three-component reaction permitting the conversion of supported peptide hydrazides into 1,2,3-triazole linked C-terminal neoglycopeptides.

Protein Chemical Synthesis by Ligation of Peptide Hydrazides

pH determines selectivity: The ligation of peptide hydrazides is a new method for protein chemical synthesis that is complementary to native chemical ligation. Peptide hydrazides may be the long-sought reagent equivalent to a “thioester synthon”, one that is stable to the conditions of native chemical ligation. Detailed facts of importance to specialist readers are published as ”Supporting Information”. Such documents are peer-reviewed, but not copy-edited or typeset. They are made available as submitted by the authors. Please note: The publisher is not responsible for the content or functionality of any supporting information supplied by the authors. Any queries (other than missing content) should be directed to the corresponding author for the article.

Protein Chemical Synthesis by Ligation of Peptide Hydrazides

Protein Chemical Synthesis by Ligation of Peptide Hydrazides

마이크로웨이브 조사와 Diisopropylcarbodiimide (DIC)/7-Aza-1-hydroxybenzotriazole (HOAt): N-Protected Amino Acid와 Hydrazine으로부터 다양한 Hydrazide합성을 위한 반응조건

마이크로웨이브 반응 장치 (Synthos 3000 Aton Paar, GmbH, 1400 W maximum magnetron)를 이용하여, diisopropylcarbodiimide (DIC)/와 1-hydroxybenzotriazoles (HOXt) (X = A or B)를 반응시켜서 amino acid hydrazide를 효율적으로 합성할 수 있는 반응 조건을 개발하였다. 일반적인 가열반응과 마이크로웨이브 반응을 반응 시간, 반응 조건 등을 비교하였을 때에, 마이크로웨이브 반응이 보다 효율적으로 진행되었으며, diisopropylcarbodiimide (DIC)와 1-hydroxybenzotriazole (HOBt) 반응에서보다는 diisopropylcarbodiimide (DIC)와 7-aza-1-hydroxybenzotriazole (HOAt)를 반응시켰을 때에 좋은 수율 (95 - 98%)로 얻어졌다. Here we describe a fast and rapid technique for preparation of amino acid hydrazide as well as peptide hydrazide derivatives using diisopropylcarbodiimide (DIC)/1-hydroxybenzotriazoles (HOXt) (X = A or B) under microwave irradiation employing a multimode reactor (Synthos 3000 Aton Paar, GmbH, 1400 W maximum magnetron). A comparison between conventional and microwave irradiation was described. The microwave methodology is rapid, convenient, proceeds under mild conditions. Diisopropylcarbodiimide (DIC)/7-aza-1-hydroxybenzotriazole (HOAt) always gave much better yield (95 - 98%) and purity than diisopropylcarbodiimide (DIC)/1-hydroxybenzotriazole (HOBt).

Silver-Catalyzed azaGly Ligation. Application to the Synthesis of Azapeptides and of Lipid−Peptide Conjugates

Glycine is a amino acid frequently found in peptides. Substitution of a glycine residue by an azaglycine allows the modulation of peptide conformation, bioactivity, or stability. Azapeptides are usually prepared using solid-phase synthetic procedures. We show here that azaGly peptides can be assembled chemoselectively and without racemization using unprotected peptide fragments by silver-catalyzed reaction of C-terminal peptide hydrazides with N-terminal phenylthiocarbonyl peptides. The reaction was performed in a tBuOH/water mixture and the control of apparent pH permitted the clean formation of the azaGly bond in the presence of lysine residues. We show also that this novel ligation method, called azaGly ligation, can be used for the assembly of lipopeptides. For this, lipid hydrazides were reacted with a phenylthiocarbonyl peptide in the presence of silver ions. This ligation method allows incorporation of acid-sensitive lipid moieties that are incompatible with standard solid-phase peptide synthesis procedures, and more generally should be of interest for the modification of peptides by sensitive acyl moieties.

Preparation of peptide p-nitroanilides using an aryl hydrazine resin.

[reaction: see text] Peptide p-nitroanilides are useful compounds for studying protease activity; however, the poor nucleophilicity of p-nitroaniline makes their preparation difficult. We describe a new efficient approach for the Fmoc-based synthesis of peptide p-nitroanilides using an aryl hydrazine resin. Mild oxidation of the peptide hydrazide resin yields a highly reactive acyl diazene that efficiently reacts with weak nucleophiles. We have prepared several peptide p-nitroanilides, including substrates for the Lethal Factor protease from B. anthracis.

Rapid cyclopeptide analysis by microwave enhanced Akabori reaction

The application of microwave assisted modification of the Akabori hydrazinolysis reaction has been found to cleave cyclic oligopeptides in a selective fashion to produce mainly the hydrazide of a specific linear peptide. This ring cleavage requires a few minutes of reaction in a domestic microwave oven. The linear peptide hydrazide can be analyzed by ESI-MS/MS, FAB-MS, and FAB-MS/MS methods for the determination of the amino acid sequence.

The carbonylhydrazone pseudopeptide link via quinonic oxidation of the peptide amino terminus

Oxidation of the amino terminus in α-amino acid derivatives using 3,5-di- tert-butyl-1,2-quinone generally failed to give the corresponding ketone, and cyclic compounds due to the nucleophilic attack of the phenol hydroxyl in the intermediate 2-aminophenol were recovered. The expected ketone was obtained by using 2,6-di- tert-butyl-1,4-quinone, and the condensation of the ketone and a peptide hydrazide gave the pseudopeptide carbonylhydrazone link.