共查询到20条相似文献,搜索用时 15 毫秒
1.
Theodorus J. Meuleman Vanessa M. Cowton Arvind H. Patel Rob M.J. Liskamp 《Journal of peptide science》2020,26(1)
In this research we describe the improvement of the water‐solubility of cyclic epitope mimics based on the HCV E2 glycoprotein by incorporation of suitable polar hinges. The poor solubility of epitope mimics based on peptide sequences in the envelope (E2) protein hampered their synthesis and purification and made it very difficult to prepare the molecular constructs for evaluation of their bioactivity. Since changes in the amino acid composition are hardly possible in these epitope mimics in order to increase water‐solubility, a polar cyclization hinge may offer a remedy leading to a significant increase of polarity and therefore water solubility. These polar hinges were applied in the synthesis of better water‐soluble HCV‐E2 epitopes. An azide functionality in the polar hinges allowed attachment of a tetraethylene glycol linker by Cu‐catalyzed azide‐alkyne cyclo‐addition (CuAAC) for a convenient conjugation to ELISA plates in order to evaluate the bio‐activity of the epitope mimics. The immunoassays showed that the use of more polar cyclization hinges still supported anti‐HCV antibody recognition and did not negatively influence their binding. This significantly increased solubility induced by polar hinges should therefore allow for the molecular construction and ultimate evaluation of synthetic vaccine molecules. 相似文献
2.
Sabine Abel Bernhard Geltinger Nadja Heinrich Dagmar Michl Annerose Klose Michael Beyermann Dirk Schwarzer 《Journal of peptide science》2014,20(11):831-836
We have recently developed a soluble mimic of the corticotropin‐releasing factor receptor type 1 (CRF1), a membrane‐spanning G protein‐coupled receptor, which allowed investigations on receptor–ligand interactions. The CRF1 mimic consists of the receptor N‐terminus and three synthetic extracellular loops (ECL1–3), which constitute the extracellular receptor domains (ECDs) of CRF1, coupled to a linear peptide template. Here, we report the synthesis of a modified CRF1 mimic, which is more similar to the native receptor possessing a cyclic template that displays the ECDs in a more physiological conformation compared with the initial linear design. In order to facilitate detailed biophysical investigations on CRF1 mimics, we have further established a cost‐efficient access to the CRF1 mimic, which is suitable for isotopic labeling for NMR spectroscopy. To this end, the loop‐mimicking cyclic peptide of the ECL2 of CRF1 was produced recombinantly and cyclized by expressed protein ligation. Cyclic ECL2 was obtained in milligram scale, and CRF1 mimics synthesized from this material displayed the same binding properties as synthetic CRF1 constructs. Copyright © 2014 European Peptide Society and John Wiley & Sons, Ltd. 相似文献
3.
Azabicyclo[X.Y.0]alkanone amino acids are challenging synthetic targets and useful tools for studying structure-activity relationships of native peptide ligands. They have been employed to increase potency and stability in conformationally rigid enzyme inhibitors and receptor ligands. Since last reviewed in 1997, activity in their synthesis and application has increased significantly and access is now available to a wider diversity of these peptide mimics. This review focuses on recent syntheses of these heterocyclic amino acids and their application in the investigation of biologically active peptides and peptide mimics. 相似文献
4.
Naoki Umezawa Nobuyoshi Matsumoto Shinsuke Iwama Nobuki Kato Tsunehiko Higuchi 《Bioorganic & medicinal chemistry》2010,18(17):6340-6350
A facile synthetic method for peptide–porphyrin conjugates containing four peptide units on one porphyrin was developed using chemoselective reactions. The key building blocks, 5,10,15,20-tetrakis(3-azidophenyl)porphyrin 1 and 5,10,15,20-tetrakis(5-azido-3-pyridyl)porphyrin 2, were efficiently synthesized and used as substrates for two well-known chemoselective reactions, traceless Staudinger ligation and copper-catalyzed azide alkyne cycloaddition (so-called click chemistry). Both reactions gave the desired compounds, and click chemistry was superior for our purpose. To confirm the value of the established methodology, nine peptide–porphyrin conjugates were synthesized, and their catalase- and peroxidase-like activity in water was evaluated. Our synthetic strategy is expected to be valuable for the preparation of artificial heme protein models. 相似文献
5.
Zhou L Thakur CS Molinaro RJ Paranjape JM Hoppes R Jeang KT Silverman RH Torrence PF 《Bioorganic & medicinal chemistry》2006,14(23):7862-7874
2',5'-Oligoadenylate tetramer (2-5A) has been chemically conjugated to short HIV-1 Tat peptides to provide 2-5A-tat chimeras. Two different convergent synthetic approaches have been employed to provide such 2-5A-tat bioconjugates. One involved generation of a bioconjugate through reaction of a cysteine terminated Tat peptide with a alpha-chloroacetyl derivative of 2-5A. The second synthetic strategy was based upon a cycloaddition reaction of an azide derivative of 2-5A with a Tat peptide bearing an alkyne function. Either bioconjugate of 2-5A-tat was able to activate human RNase L. The union of 2-5A and Tat peptide provided an RNase L-active chimeric nucleopeptide with the ability to be taken up by cells by virtue of the Tat peptide and to activate RNase L in intact cells. This strategy provides a valuable vehicle for the entry of the charged 2-5A molecule into cells and may provide a means for targeted destruction of HIV RNA in vivo. 相似文献
6.
Tomoaki Anabuki Miu Tsukahara Masanori Okamoto Hideyuki Matsuura Kosaku Takahashi 《Bioorganic & medicinal chemistry letters》2018,28(4):783-786
We synthesized a novel linker (1) with biotin, alkyne and amino groups for the identification of target proteins using a small molecule that contains an azide group (azide probe). The alkyne in the linker bound the azide probe via an azide-alkyne Huisgen cycloaddition. A protein cross-linker effectively bound the conjugate of the linker and an azide probe with a target protein. The covalently bound complex was detected by western blotting. Linker 1 was applied to a model system using an abscisic acid receptor, RCAR/PYR/PYL (PYL). Cross-linked complexes of linker 1, the azide probes and the target proteins were successfully visualized by western blotting. This method of target protein identification was more effective than a previously developed method that uses a second linker with biotin, alkyne, and benzophenone (linker 2) that acts to photo-crosslink target proteins. The system developed in this study is a method for identifying the target proteins of small bioactive molecules and is different from photo-affinity labelling. 相似文献
7.
Kishore Thalluri Binbin Kou Xu Yang Alexander N. Zaykov John P. Mayer Vasily M. Gelfanov Fa Liu Richard D. DiMarchi 《Journal of peptide science》2017,23(6):455-465
This report presents an entirely chemical, general strategy for the synthesis of relaxin‐2 and insulin‐like peptide 5. Historically, these two peptides have represented two of the more synthetically challenging members of the insulin superfamily. The key synthetic steps involve two sequential oxime ligations to covalently link the individual A‐chain and B‐chain, followed by disulfide bond formation under aqueous, redox conditions. This is followed by two chemical reactions that employ diketopiperazine cyclization‐mediated cleavage and ester hydrolysis to liberate the connecting peptide and the heterodimeric product. This approach avoids the conventional iodine‐mediated disulfide bond formation and enzyme‐assisted proteolysis to generate biologically active two‐chain peptides. This novel synthetic strategy is ideally suited for peptides such as relaxin and insulin‐like peptide 5 as they possess methionine and tryptophan that are labile under strong oxidative conditions. Additionally, these peptides possess multiple arginine and lysine residues that preclude the use of trypsin‐like enzymes to obtain biologically active hormones. This synthetic methodology is conceivably applicable to other two‐chain peptides that contain multiple disulfide bonds. Copyright © 2017 European Peptide Society and John Wiley & Sons, Ltd. 相似文献
8.
Today, Fmoc SPPS is the method of choice for peptide synthesis. Very‐high‐quality Fmoc building blocks are available at low cost because of the economies of scale arising from current multiton production of therapeutic peptides by Fmoc SPPS. Many modified derivatives are commercially available as Fmoc building blocks, making synthetic access to a broad range of peptide derivatives straightforward. The number of synthetic peptides entering clinical trials has grown continuously over the last decade, and recent advances in the Fmoc SPPS technology are a response to the growing demand from medicinal chemistry and pharmacology. Improvements are being continually reported for peptide quality, synthesis time and novel synthetic targets. Topical peptide research has contributed to a continuous improvement and expansion of Fmoc SPPS applications. Copyright © 2015 European Peptide Society and John Wiley & Sons, Ltd. 相似文献
9.
Alexandra Le Chevalier Isaad Anna Maria Papini Michael Chorev Paolo Rovero 《Journal of peptide science》2009,15(7):451-454
CuI‐catalyzed azide‐alkyne 1,3‐dipolar Huisgen's cycloaddition (CuAAC) is a click reaction that has drawn a lot of attention, in general, and in the field of peptide and protein sciences, in particular. Among several reported applications, the preparation of novel heterodetic cyclopeptides by an intramolecular side chain‐to‐side chain CuAAC, forming a 1,4‐disubstituted[1,2,3]triazolyl‐containing bridge, is of great interest. Herein, we provide a detailed protocol for the syntheses of model heterodetic cyclopeptides as a prototypical intramolecular CuAAC, using as a model a sequence derived from parathyroid hormone‐related protein. Copyright © 2009 European Peptide Society and John Wiley & Sons, Ltd. 相似文献
10.
A cleavable self‐assembling tag strategy for preparing proteins and peptides with an authentic N‐terminus
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Recombinant protein expression and purification remains a central need for biotechnology. Herein, the authors report a streamlined protein and peptide purification strategy using short self‐assembling peptides and a C‐terminal cleavage intein. In this strategy, the fusion protein is first expressed as an aggregate induced by the self‐assembling peptide. Upon simple separation, the target protein or peptide with an authentic N‐terminus is then released in the solution by intein‐mediated cleavage. Different combinations of four self‐assembling peptides (ELK16, L6KD, FK and FR) with three inteins (Sce VMA, Mtu ΔI‐CM and Ssp DnaB) were explored. One protein and two peptides were used as model polypeptides to test the strategy. The intein Mtu ΔI‐CM, which has pH‐shift inducible cleavage, was found to work well with three self‐assembling peptides (L6KD, FR, FK). Using this intein gave a yield of protein or peptide comparable with that from other more established strategies, such as the Trx‐strategy, but in a simpler and more economical way. This strategy provides a simple and efficient method by which to prepare proteins and peptides with an authentic N‐terminus, which is especially effective for peptides of 30‐100 amino acids in length that are typically unstable and susceptible to degradation in Escherichia coli. 相似文献
11.
The absolute quantification strategy: a general procedure for the quantification of proteins and post-translational modifications 总被引:3,自引:0,他引:3
Advances in biological mass spectrometry have resulted in the development of numerous strategies for the large-scale quantification of protein expression levels within cells. These measurements of protein expression are most commonly accomplished through differential incorporation of stable isotopes into cellular proteins. Several variations of the stable isotope quantification method have been demonstrated, differing in isotope composition and incorporation strategy. In general, the majority of these methods establish only relative quantification of expressed proteins. To address this, the absolute quantification (AQUA) strategy was developed for the precise determination of protein expression and post-translational modification levels. The AQUA method relies on the use of a synthetic internal standard peptide that is introduced at a known concentration to cell lysates during digestion. This AQUA peptide precisely mimics a peptide produced during proteolysis of the target protein, except that it is enriched in certain stable isotopes. Analysis of the proteolyzed sample by a selected reaction monitoring (SRM) experiment in a tandem mass spectrometer results in the direct detection and quantification of both the native peptide and isotope labeled AQUA internal standard peptide. As an example, the development and application of a method to measure a tryptic peptide representing the amount of polyubiquitin chain formation through lysine 48 (K48) is presented. The simplicity and sensitivity of the method, coupled with the widespread availability of tandem mass spectrometers, make the AQUA strategy a highly useful procedure for measuring the levels of proteins and post-translational modifications directly from cell lysates. 相似文献
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14.
The conformational restriction of synthetic peptides, including a malaria peptide, for use as immunogens 总被引:1,自引:0,他引:1
A C Satterthwait T Arrhenius R A Hagopian F Zavala V Nussenzweig R A Lerner 《Philosophical transactions of the Royal Society of London. Series B, Biological sciences》1989,323(1217):565-572
A new strategy is advanced for the conformational restriction of peptidyl immunogens. Our approach is to replace putative amide-amide hydrogen bonds with covalent hydrogen-bond mimics. Because on average every other amino acid in a protein engages in this bond, the syntheses of diversely shaped peptides can be contemplated. Synthetic methods for introducing a potential hydrogen-bond mimic into a peptide with alpha-helical potential is reported and the structural consequences are discussed. The replacement of the hydrogen bond with a chemical link will modify as well as shape the peptide. To explore the consequences of these changes, a potential synthetic vaccine for malaria, the repeating tetrapeptide Asn-Pro-Asn-Ala, was conformationally restricted. Antibodies to the shaped malarial peptide showed a strong cross reaction with Plasmodium falciparum sporozoites. 相似文献
15.
Rong Xue Shuo Wang Haiyan Qi Yuande Song Shuyan Xiao Fei Li 《Journal of peptide science》2009,15(5):377-384
Natural resistance associated macrophage protein 1 (Nramp1), an integral membrane protein with 12 predicted transmembrane domains (TMs), is a divalent cation transporter associated with infectious and autoimmune diseases. A naturally occurring mutation G169D within TM4 of Nramp1 leads to the loss of function, suggesting potential importance of TM4 for the biological function of the protein. In this study, we determine the three‐dimensional structure and topology of a synthetic peptide, del(T178), corresponding to Nramp1(164‐191) (basically consisting of the putative TM4 of Nramp1) with Thr178 deletion in TFE and SDS micelles using NMR and CD spectroscopic techniques, and compare the results with those of the wildtype peptide. Similarly to the wildtype peptide, the del(T178) peptide still forms an amphiphilic‐like α‐helical structure in both membrane mimics and is embedded in SDS micelles. Differently, whereas the wild‐type peptide forms a helix bundle with the hydrophilic side facing the interior of the bundle, the del(T178) peptide exists as a monomer in the membrane mimics and the hydrophilic side of the helix is located near the interface of SDS micelles. Moreover, a strongly cooperative protonation occurs between intramolecular Asp residues for the del(T178) peptide in SDS micelles, while the cooperative proton binding between intermolecular Asp residues was observed for the wildtype peptide. The difference in the results of the two peptides suggests that the deletion of Thr178 impairs intermolecular interaction of the peptide. Copyright © 2009 European Peptide Society and John Wiley & Sons, Ltd. 相似文献
16.
Johnathan C. Maza Christina A. Howard Megha A. Vipani Christopher R. Travis Douglas D. Young 《Bioorganic & medicinal chemistry letters》2017,27(1):30-33
The ability to introduce or modify protein function has widespread application to multiple scientific disciplines. The introduction of unique unnatural amino acids represents an excellent mechanism to incorporate new functionality; however, this approach is limited by ability of the translational machinery to recognize and incorporate the chemical moiety. To overcome this potential limitation, we aimed to exploit the functionality of existing unnatural amino acids to perform bioorthogonal reactions to introduce the desired protein modification, altering its function. Specifically, via the introduction of a terminal alkyne containing unnatural amino acid, we demonstrated chemically programmable protein modification through the Glaser-Hay coupling to other terminal alkynes, altering the function of a protein. In a proof-of-concept experiment, this approach has been utilized to modify the fluorescence spectrum of green fluorescent protein. 相似文献
17.
Karel Guillemyn Dirk Tourwé Yves Jacquot Steven Ballet 《Journal of peptide science》2013,19(7):423-432
A model octapeptide segment derived from vasoactive intestinal peptide (VIP) was utilised to investigate the effect of several conventional cyclisation methods on the α‐helical conformation in short peptide fragments. Three of the classical macrocyclisation techniques (i.e. lactamisation, ring‐closing metathesis and Huisgen cycloaddition) were applied, and the conformations of the resulting cyclic peptides, as well as their linear precursors, were compared by CD analysis. The visibly higher folding propensity of the triazole‐tethered peptide after azide‐alkyne CuAAC macrocyclisation illustrates that the secondary structure of a short peptide fragment can differ significantly depending on the chemical strategy used to covalently cross‐link side chain residues in a ‘helical’ fragment. Copyright © 2013 European Peptide Society and John Wiley & Sons, Ltd. 相似文献
18.
Tony Velkov James D. Swarbrick Maytham H. Hussein Elena K. Schneider‐Futschik Daniel Hoyer Jian Li John A. Karas 《Journal of peptide science》2019,25(9)
Antimicrobial resistance is a serious threat to global human health; therefore, new anti‐infective therapeutics are required. The cyclic depsi‐peptide teixobactin exhibits potent antimicrobial activity against several Gram‐positive pathogens. To study the natural product's mechanism of action and improve its pharmacological properties, efficient chemical methods for preparing teixobactin analogues are required to expedite structure‐activity relationship studies. Described herein is a synthetic route that enables rapid access to analogues. Furthermore, our new N‐methylated analogues highlight that hydrogen bonding along the N‐terminal tail is likely to be important for antimicrobial activity. 相似文献
19.
Crustacean insulin‐like androgenic gland factor (IAG) of Macrobrachium rosenbergii, a heterodimeric peptide having both four disulfide bonds and an N‐linked glycan, was synthesized by the combination of solid‐phase peptide synthesis and the regioselective disulfide formation reactions. The disulfide isomer of IAG could also be synthesized by the same manner. The conformational analysis of these peptides by circular dichroism (CD) spectral measurement indicated that the disulfide bond arrangement affected the peptide conformation in IAG. On the other hand, the N‐linked glycan attached at A chain showed no effect on CD spectra of IAG. This is the first report for the chemical synthesis of insulin‐like heterodimeric glycopeptide having three interchain disulfides, and the synthetic strategy shown here might be useful for the synthesis of other glycosylated four‐disulfide insulin‐like peptides. 相似文献
20.
Epitope mapping of anti‐myelin oligodendrocyte glycoprotein (MOG) antibodies in a mouse model of multiple sclerosis: microwave‐assisted synthesis of the peptide antigens and ELISA screening
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Giulia Pacini Matthaia Ieronymaki Francesca Nuti Giuseppina Sabatino Maud Larregola Rina Aharoni Anna Maria Papini Paolo Rovero 《Journal of peptide science》2016,22(1):52-58
The role of pathologic auto‐antibodies against myelin oligodendrocyte glycoprotein (MOG) in multiple sclerosis is a highly controversial matter. As the use of animal models may enable to unravel the molecular mechanisms of the human disorder, numerous studies on multiple sclerosis are carried out using experimental autoimmune encephalomyelitis (EAE). In particular, the most extensively used EAE model is obtained by immunizing C57BL/6 mice with the immunodominant peptide MOG(35–55). In this scenario, we analyzed the anti‐MOG antibody response in this model using the recombinant refolded extracellular domain of the protein, MOG(1–117). To assess the presence of a B‐cell intramolecular epitope spreading mechanism, we tested also five synthetic peptides mapping the 1–117 sequence of MOG, including MOG(35–55). For this purpose, we cloned, expressed in Escherichia coli and on‐column refolded MOG(1–117), and we applied an optimized microwave‐assisted solid‐phase synthetic strategy to obtain the designed peptide sequences. Subsequently, we set up a solid‐phase immunoenzymatic assay testing both naïve and EAE mice sera and using MOG protein and peptides as antigenic probes. The results obtained disclose an intense IgG antibody response against both the recombinant protein and the immunizing peptide, while no response was observed against the other synthetic fragments, thus excluding the presence of an intramolecular epitope spreading mechanism. Furthermore, as the properly refolded recombinant probe is able to bind antibodies with greater efficiency compared with MOG(35–55), we hypothesize the presence of both linear and conformational epitopes on MOG(35–55) sequence. Copyright © 2015 European Peptide Society and John Wiley & Sons, Ltd. 相似文献