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Littérature scientifique sur le sujet « Sulfur Peptide »

Auteur : Grafiati

Publié le 1 avril 2023

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Articles de revues sur le sujet "Sulfur Peptide"

Rademann, Jörg, Ahsanullah Ahsanullah, Abbas Hassan et Farzana L. Ansari. « Integration of C-Acylation in the Solid-Phase Synthesis of Peptides and Peptidomimetics Employing Meldrum’s Acid, Phosphorus, and Sulfur Ylides ». Synthesis 54, n^o 06 (12 octobre 2021) : 1503–17. http://dx.doi.org/10.1055/a-1667-3648.

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AbstractThe modification of native peptides to peptidomimetics is an important goal in medicinal chemistry and requires, in many cases, the integration of C-acylation steps involving amino acids with classical peptide synthesis. Many classical C-acylation protocols involving Claisen condensations and the use of ylides are not compatible with peptide synthesis, mostly due to the requirements for strong bases leading to epimerization or deprotection of peptides. Meldrum’s acid as well as several specific phosphorus and sulfur ylides, however, are acidic enough to provide reactive C-nucleophiles under mildly basic conditions tolerated during peptide synthesis. This review provides an overview of peptide-compatible C-acylations using Meldrum’s acid and phosphorus and sulfur ylides, and their application in the medicinal chemistry of peptides.1 Introduction2 C-Acylation of Meldrum’s Acid2.1 C-Acylation of Meldrum’s Acid on Solid Phase3 Ylides as Substrates for C-Acylation3.1 C-Acylation of Phosphorus Ylides in Solution Phase3.2 C-Acylation of Solid-Supported Phosphorus Ylides3.3 C-Acylation of Sulfur Ylides3.4 C-Acylation of Solid-Supported Sulfur Ylides4 Miscellaneous Ylides as Acyl Anion Equivalents5 Summary

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Neugebauer, W. J., et E. Escher. « Peptide labelling with sulfur-35 ». International Journal of Radiation Applications and Instrumentation. Part A. Applied Radiation and Isotopes 39, n^o 6 (janvier 1988) : 539. http://dx.doi.org/10.1016/0883-2889(88)90255-9.

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Adams, Michael W. W., James F. Holden, Angeli Lal Menon, Gerrit J. Schut, Amy M. Grunden, Chun Hou, Andrea M. Hutchins et al. « Key Role for Sulfur in Peptide Metabolism and in Regulation of Three Hydrogenases in the Hyperthermophilic ArchaeonPyrococcus furiosus ». Journal of Bacteriology 183, n^o 2 (15 janvier 2001) : 716–24. http://dx.doi.org/10.1128/jb.183.2.716-724.2001.

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ABSTRACT The hyperthermophilic archaeon Pyrococcus furiosusgrows optimally at 100°C by the fermentation of peptides and carbohydrates. Growth of the organism was examined in media containing either maltose, peptides (hydrolyzed casein), or both as the carbon source(s), each with and without elemental sulfur (S0). Growth rates were highest on media containing peptides and S0, with or without maltose. Growth did not occur on the peptide medium without S0. S0 had no effect on growth rates in the maltose medium in the absence of peptides. Phenylacetate production rates (from phenylalanine fermentation) from cells grown in the peptide medium containing S0 with or without maltose were the same, suggesting that S0 is required for peptide utilization. The activities of 14 of 21 enzymes involved in or related to the fermentation pathways of P. furiosus were shown to be regulated under the five different growth conditions studied. The presence of S0 in the growth media resulted in decreases in specific activities of two cytoplasmic hydrogenases (I and II) and of a membrane-bound hydrogenase, each by an order of magnitude. The primary S0-reducing enzyme in this organism and the mechanism of the S0 dependence of peptide metabolism are not known. This study provides the first evidence for a highly regulated fermentation-based metabolism in P. furiosus and a significant regulatory role for elemental sulfur or its metabolites.

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Kaufmann, Christine, et Margret Sauter. « Sulfated plant peptide hormones ». Journal of Experimental Botany 70, n^o 16 (20 juin 2019) : 4267–77. http://dx.doi.org/10.1093/jxb/erz292.

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Abstract Sulfated peptides are plant hormones that are active at nanomolar concentrations. The sulfation at one or more tyrosine residues is catalysed by tyrosylprotein sulfotransferase (TPST), which is encoded by a single-copy gene. The sulfate group is provided by the co-substrate 3´-phosphoadenosine 5´-phosphosulfate (PAPS), which links synthesis of sulfated signaling peptides to sulfur metabolism. The precursor proteins share a conserved DY-motif that is implicated in specifying tyrosine sulfation. Several sulfated peptides undergo additional modification such as hydroxylation of proline and glycosylation of hydroxyproline. The modifications render the secreted signaling molecules active and stable. Several sulfated signaling peptides have been shown to be perceived by leucine-rich repeat receptor-like kinases (LRR-RLKs) but have signaling pathways that, for the most part, are yet to be elucidated. Sulfated peptide hormones regulate growth and a wide variety of developmental processes, and intricately modulate immunity to pathogens. While basic research on sulfated peptides has made steady progress, their potential in agricultural and pharmaceutical applications has yet to be explored.

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Francioso, Antonio, Alessia Baseggio Conrado, Carla Blarzino, Cesira Foppoli, Elita Montanari, Simone Dinarelli, Alessandra Giorgi, Luciana Mosca et Mario Fontana. « One- and Two-Electron Oxidations of β-Amyloid25-35 by Carbonate Radical Anion (CO3•−) and Peroxymonocarbonate (HCO4−) : Role of Sulfur in Radical Reactions and Peptide Aggregation ». Molecules 25, n^o 4 (20 février 2020) : 961. http://dx.doi.org/10.3390/molecules25040961.

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The β-amyloid (Aβ) peptide plays a key role in the pathogenesis of Alzheimer’s disease. The methionine (Met) residue at position 35 in Aβ C-terminal domain is critical for neurotoxicity, aggregation, and free radical formation initiated by the peptide. The role of Met in modulating toxicological properties of Aβ most likely involves an oxidative event at the sulfur atom. We therefore investigated the one- or two-electron oxidation of the Met residue of Aβ25-35 fragment and the effect of such oxidation on the behavior of the peptide. Bicarbonate promotes two-electron oxidations mediated by hydrogen peroxide after generation of peroxymonocarbonate (HCO4−, PMC). The bicarbonate/carbon dioxide pair stimulates one-electron oxidations mediated by carbonate radical anion (CO3•−). PMC efficiently oxidizes thioether sulfur of the Met residue to sulfoxide. Interestingly, such oxidation hampers the tendency of Aβ to aggregate. Conversely, CO3•− causes the one-electron oxidation of methionine residue to sulfur radical cation (MetS•+). The formation of this transient reactive intermediate during Aβ oxidation may play an important role in the process underlying amyloid neurotoxicity and free radical generation.

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Prütz, Walter A., John Butler, Edward J. Land et A. John Swallow. « Unpaired Electron Migration between Aromatic and Sulfur Peptide Units ». Free Radical Research Communications 2, n^o 1-2 (janvier 1986) : 69–75. http://dx.doi.org/10.3109/10715768609088056.

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Kosted, Paula J., Shirley A. Gerhardt et John E. Sherwood. « Pheromone-Related Inhibitors of Ustilago hordei Mating and Tilletia tritici Teliospore Germination ». Phytopathology® 92, n^o 2 (février 2002) : 210–16. http://dx.doi.org/10.1094/phyto.2002.92.2.210.

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Ustilago hordei, the causal agent of barley covered smut, produces mating pheromones that break down to smaller peptide compounds that act as potent inhibitors of mating and germination in several fungi. The pheromones are members of the farnesylated family of proteins. Synthetic peptide analogs of the pheromone derivatives, ranging in size from 4 mers to full length pheromones, were farnesylated, methyl esterified, or both and tested for mating or teliospore germination inhibition with U. hordei or Tilletia tritici, respectively. N-Acetyl-S-farnesylcysteine, which inhibits processing of Ras, and other sulfur-containing compounds such as homocysteine or methionine, were likewise modified and tested. The most potent inhibitors were methionine methyl ester and modified 4-mer peptides from both pheromones. Alanine scanning of the inhibitory 4 mers determined that the native amino acid sequence was specific for a high level of activity. The sulfur amino acids appear to be required for inhibition. Glasshouse studies using selected antagonists of mating and teliospore germination as seed treatments inhibited covered smut of barley and common bunt of wheat, although the level of control was inconsistent. The use of pheromone-related antagonists to mating or teliospore germination is a promising, novel strategy for control of smut and bunt diseases.

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Abe, Tomoko, Yoshiteru Hashimoto, Ye Zhuang, Yin Ge, Takuto Kumano et Michihiko Kobayashi. « Peptide Bond Synthesis by a Mechanism Involving an Enzymatic Reaction and a Subsequent Chemical Reaction ». Journal of Biological Chemistry 291, n^o 4 (19 novembre 2015) : 1735–50. http://dx.doi.org/10.1074/jbc.m115.700989.

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We recently reported that an amide bond is unexpectedly formed by an acyl-CoA synthetase (which catalyzes the formation of a carbon-sulfur bond) when a suitable acid and l-cysteine are used as substrates. DltA, which is homologous to the adenylation domain of nonribosomal peptide synthetase, belongs to the same superfamily of adenylate-forming enzymes, which includes many kinds of enzymes, including the acyl-CoA synthetases. Here, we demonstrate that DltA synthesizes not only N-(d-alanyl)-l-cysteine (a dipeptide) but also various oligopeptides. We propose that this enzyme catalyzes peptide synthesis by the following unprecedented mechanism: (i) the formation of S-acyl-l-cysteine as an intermediate via its “enzymatic activity” and (ii) subsequent “chemical” S → N acyl transfer in the intermediate, resulting in peptide formation. Step ii is identical to the corresponding reaction in native chemical ligation, a method of chemical peptide synthesis, whereas step i is not. To the best of our knowledge, our discovery of this peptide synthesis mechanism involving an enzymatic reaction and a subsequent chemical reaction is the first such one to be reported. This new process yields peptides without the use of a thioesterified fragment, which is required in native chemical ligation. Together with these findings, the same mechanism-dependent formation of N-acyl compounds by other members of the above-mentioned superfamily demonstrated that all members most likely form peptide/amide compounds by using this novel mechanism. Each member enzyme acts on a specific substrate; thus, not only the corresponding peptides but also new types of amide compounds can be formed.

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Keegan, Brenna C., Daniel Ocampo et Jason Shearer. « pH Dependent Reversible Formation of a Binuclear Ni2 Metal-Center within a Peptide Scaffold ». Inorganics 7, n^o 7 (16 juillet 2019) : 90. http://dx.doi.org/10.3390/inorganics7070090.

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A disulfide-bridged peptide containing two Ni2+ binding sites based on the nickel superoxide dismutase protein, {Ni2(SODmds)} has been prepared. At physiological pH (7.4), it was found that the metal sites are mononuclear with a square planar NOS2 coordination environment with the two sulfur-based ligands derived from cysteinate residues, the nitrogen ligand derived from the amide backbone, and a water ligand. Furthermore, S K-edge X-ray absorption spectroscopy indicated that the two cysteinate sulfur atoms ligated to nickel are each protonated. Elevation of the pH to 9.6 results in the deprotonation of the cysteinate sulfur atoms, and yields a binuclear, cysteinate bridged Ni22+ center with each nickel contained in a distorted square planar geometry. At both pH = 7.4 and 9.6, the nickel sites are moderately air sensitive, yielding intractable oxidation products. However, at pH = 9.6, {Ni2(SODmds)} reacts with O2 at an ~3.5-fold faster rate than at pH = 7.4. Electronic structure calculations indicate that the reduced reactivity at pH = 7.4 is a result of a reduction in S(3p) character and deactivation of the nucleophilic frontier molecular orbitals upon cysteinate sulfur protonation.

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Zeng, Xiang, Xiaobo Zhang et Zongze Shao. « Metabolic Adaptation to Sulfur of Hyperthermophilic Palaeococcus pacificus DY20341T from Deep-Sea Hydrothermal Sediments ». International Journal of Molecular Sciences 21, n^o 1 (6 janvier 2020) : 368. http://dx.doi.org/10.3390/ijms21010368.

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The hyperthermo-piezophilic archaeon Palaeococcus pacificus DY20341T, isolated from East Pacific hydrothermal sediments, can utilize elemental sulfur as a terminal acceptor to simulate growth. To gain insight into sulfur metabolism, we performed a genomic and transcriptional analysis of Pa. pacificus DY20341T with/without elemental sulfur as an electron acceptor. In the 2001 protein-coding sequences of the genome, transcriptomic analysis showed that 108 genes increased (by up to 75.1 fold) and 336 genes decreased (by up to 13.9 fold) in the presence of elemental sulfur. Palaeococcus pacificus cultured with elemental sulfur promoted the following: the induction of membrane-bound hydrogenase (MBX), NADH:polysulfide oxidoreductase (NPSOR), NAD(P)H sulfur oxidoreductase (Nsr), sulfide dehydrogenase (SuDH), connected to the sulfur-reducing process, the upregulation of iron and nickel/cobalt transfer, iron–sulfur cluster-carrying proteins (NBP35), and some iron–sulfur cluster-containing proteins (SipA, SAM, CobQ, etc.). The accumulation of metal ions might further impact on regulators, e.g., SurR and TrmB. For growth in proteinous media without elemental sulfur, cells promoted flagelin, peptide/amino acids transporters, and maltose/sugar transporters to upregulate protein and starch/sugar utilization processes and riboflavin and thiamin biosynthesis. This indicates how strain DY20341T can adapt to different living conditions with/without elemental sulfur in the hydrothermal fields.

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Thèses sur le sujet "Sulfur Peptide"

Hippauf, Felix. « Tailoring Pore Size and Polarity for Liquid Phase Adsorption by Porous Carbons ». Doctoral thesis, Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2017. http://nbn-resolving.de/urn:nbn:de:bsz:14-qucosa-223482.

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Adsorption is a versatile purification technique to selectively separate different peptide fractions from a mixture using mild operation conditions. Porous carbons are ideally suited to separate ACE-inhibiting dipeptides by combining tailored size exclusion and polarity selectivity. The desired peptide fraction is mostly hydrophobic and very small and should adsorb inside hydrophobic micropores. The second topic of this thesis is linked to energy storage. The lithium-sulfur battery is a promising alternative to common lithium-ion batteries with theoretical capacities of up to 1672 mAh g−1 sulfur. The second aim of this thesis is to conduct an in-depth investigation of polysulfides interacting with selected carbon materials in a simplified battery electrolyte environment. The focus of this study is laid on the impact of surface polarity and pore size distribution of the carbon to develop a quantitative correlation between polysulfide retention and porosity metrics. Both, the enrichment of ACE-inhibitors and the retention of polysulfides rely on liquid phase adsorption in porous materials, linking the above mentioned topics. This thesis not only aims to develop an enrichment process or to find a superior battery cathode but also strives to explore structure-property relationships that are universally valid. Understanding the complex interplay of pore size and polarity leading to selective interactions between pore wall and the adsorbed species is given a high priority.

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Chappell, Paul Elliott. « Structural studies of peptide binding to chicken class I MHC molecules, the CD6-CD166 interaction and enzymes involved in bacterial sulfur metabolism ». Thesis, University of Oxford, 2015. https://ora.ox.ac.uk/objects/uuid:d4fa5a1b-530b-4a10-8184-02742cfa34f6.

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T cell activation is critical for the initiation of the adaptive immune response against both pathogens and malignant cells. This process depends on a complex set of finely tuned interactions, not only between the T cell receptor (TCR) and peptide-MHC complexes, but also between numerous accessory molecules. Chapter 2 of this thesis examines CD6, a transmembrane glycoprotein predominantly found on the surface of T cells, and its interaction with CD166, another transmembrane glycoprotein found on the surface of antigen presenting cells (APCs), amongst others. This interaction is required for optimal T cell activation. I have solved the X-ray crystal structures of the three extracellular SRCR domains of CD6 and the two membrane distal IgSF domains of CD166. In collaboration with colleagues, the ligand binding sites on both CD6 and CD166 have been further defined. We have also shown that a single nucleotide polymorphism (SNP) in CD6 caused glycosylation, hindering the CD6/CD166 interaction. Finally, native mass spectrometry revealed competition between the heterophilic CD6/CD166 interaction and the homophilic CD166 interaction.

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Yamamoto, Masaru. « Synthesis and oxidation studies of sulfur containing inhibitors for human leukocyte elastase : (2) synthesis of cyclic peptide analogs for tissue factor pathway inhibitor (TFPI) : Part 2 synthesis and evaluation of aziridinecarboxylic acid analogs as a new family of cysteine proteinase inhibitors ». Diss., Georgia Institute of Technology, 1993. http://hdl.handle.net/1853/25953.

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Valer, Luca. « Histidine ligated Iron-Sulfur Proteins and Peptides ». Doctoral thesis, Università degli studi di Trento, 2022. https://hdl.handle.net/11572/355641.

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Iron-sulfur clusters play a fundamental role in biology and are believed to be ancient cofactors that could have played a role in early protometabolic systems. Thus far, redox active, prebiotically plausible iron-sulfur clusters have always been obtained through cysteine coordination to the iron ions. However, extant iron-sulfur proteins can be found to exploit other modes of binding, including ligation by histidine residues, as seen with [2Fe-2S] Rieske and MitoNEET proteins. In this thesis, we investigated the ability of cysteine- and histidine-containing proteins and peptides to coordinate mononuclear [1Fe-0S] centers and a [2Fe-2S] clusters. The iron-sulfur peptides were characterized by UV-vis, circular dichroism, and paramagnetic NMR spectroscopies and cyclic voltammetry. Small (≤ 6 amino acids) peptides can coordinate [2Fe-2S] clusters through a combination of cysteine and histidine residues with similar reduction potentials as their corresponding proteins. Such complexes may have been important for early cell-like systems.

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Matteucci, Mizio. « Solid phase synthesis and applications of sulfur bridged peptides ». Thesis, University of Southampton, 2003. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.274652.

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Hautier, Alexandre. « Synthesis and characterization of copper-peptide systems for oxidation catalysis ». Thesis, Aix-Marseille, 2018. http://www.theses.fr/2018AIXM0758.

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La catalyse permet de réaliser des transformations efficaces à un coût énergétique plus faible qu'avec des réactions non catalysées. Le développement d’un catalyseur peut souvent être inspiré par la Nature qui parvient à réaliser des transformations chimiques difficiles avec de hauts rendements et une grande sélectivité et ce en milieu aqueux dans des conditions douces. Par exemple, les protéines dépendantes du cuivre peuvent oxyder une large gamme de substrats. Inspirés par les systèmes biologiques, les metallopeptides ont récemment émergés en tant que plate-forme fiable pour développer de nouveaux catalyseurs grâce à leur facilité d’accès, de maniement et d’affinage de leurs propriétés. Dans cette thèse, nous décrivons la synthèse d’une famille de décapeptides bio-inspirés, qui contiennent des résidus His et Asp permettant de coordiner des ions métalliques. Les données indiquent que tous les peptides se lient au cuivre et qu’ils forment, à un pH proche de la neutralité, une espèce cuivre (II) majoritaire, similaire entre tous les peptides. Dans ces complexes, les peptides lient le cuivre (II) par les chaines latérales des résidus His et Asp. Pour finir, la capacité de ces systèmes ainsi que des complexes cuivre (II)-amyloid-β à catalyser des transformations oxydantes en solution aqueuse en utilisant H2O2 comme oxydants a été évaluée. Cette étude révèle que i) la structure des peptides à un impact sur les rendements catalytiques et sur l’obtention d’excès énantiomérique, et que ii) les complexes cuivre (II)-amyloid-β sont moins performants que nos systèmes cuivre (II)-peptide
Catalysis gives access to efficient transformations at a lower cost in energy and generally offers possibilities to reduce or eliminate the need for and the generation of hazardous compounds . The development of a catalyst is often inspired by Nature that performs challenging chemical transformations with high rates and high selectivity under mild conditions and aqueous media. For example, copper dependent proteins can react to oxidize a broad range of substrates. Inspired by biological systems, metallopeptides have recently emerged as reliable platforms to evolve new catalysts because they are chemically accessible, easy to handle and fine-tune.In this work we synthetized a family of bioinspired decapeptides containing His and Asp residues as metal ion coordinating amino acids. Their copper coordination properties were studied using pH potentiometry, and different spectroscopic techniques (UV-Vis, CD, EPR, NMR). The data indicates that all the peptides bind copper and form similar major copper(II) species at a pH close to neutrality where copper (II) is coordinated by the side-chains of His and Asp residues. Finally, the capabilities of these metallopeptides to perform a variety of oxidative transformations in aqueous solution at room temperature, using H2O2 as the oxidant were evaluated in parallel with that of amyloid-β peptides copper (II) complexes. This study revealed that i) the scaffold of the designed peptides had an impact on the catalytic efficiencies and enantiomeric excess and ii) the amyloid-β peptides copper (II) complexes are less active than our designed copper(II) peptide systems

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Srour, Batoul. « Emerging roles for natural and artificial lipids in shaping the catalytic function, stability and oligomeric state of membrane proteins ». Thesis, Strasbourg, 2015. http://www.theses.fr/2015STRAF068/document.

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L'étude des membranes biologiques nécessite l'examen des différentes propriétés de ses composantes principales: les lipides et les protéines. Dans ce manuscrit, l'interaction lipide- lipide et lipide-protéine ont été suivies par spectroscopie vibrationnelle (Raman, Infrarouge). Nous sommes intéressés en premier lieu à l'étude de la structure et l'organisation des phospholipides dans leur phase gel et leur phase cristalline liquide en utilisant la spectroscopie moyen infrarouge. En outre, l'effet de la composition du groupement hydrophiles des lipides sur le comportement de la liaison hydrogène des mélanges lipidiques a été sondé en utilisant la spectroscopie lointain infrarouge. Dans la seconde partie, l'interaction de la protéine NADH ubiquinone oxydoréductase et du mutant NuoL (D563N) avec le zinc ont été étudiés par spectroscopie différentielle et les changements conformationnels induits par la liaison du zinc avec les protéines ont été examinés. Enfin, les vibrations métal-ligand des groupements fer-soufre dans le mutant de NuoB (C64A G100C) à différents pH ont été analysées par spectroscopie Raman
The study of biological membranes involves the examination of the different properties of its main components: as lipids and proteins. In this manuscript, the lipid-lipid interaction and the lipid-protein interaction were monitored by vibrational spectroscopy (Raman and Infrared). We have been interested in the first part in studying the structure and organization of phospholipids in the gel phase and the liquid crystalline phase using mid infrared spectroscopy. In addition, the effect of the head group composition on the hydrogen bonding behaviour of lipid mixtures was probed using far infrared spectroscopy. In the second part, the interaction of the NADH ubiquinone oxidoreductase protein and NuoL mutant (D563N) with zinc was investigated through FTIR difference spectroscopy where the conformational changes upon zinc binding were monitored. Finally, the metal-ligand vibrations of the iron- sulfur clusters in NuoB mutants (C64A G100C) at different pH were analysed using Raman spectroscopy

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Rossetto, Daniele. « Emergence, survival, and selection of metal-binding peptides in the prebiotic environment ». Doctoral thesis, Università degli studi di Trento, 2022. https://hdl.handle.net/11572/355344.

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Metabolism is a subset of chemistry that allows cells to defy thermodynamic equilibrium, a fundamental process that must have been in place from the very beginning of biology. Before evolution produced efficient catalysts in the form of complex protein machinery, short metal binding peptides might have preceded modern metalloproteins. Such prebiotic, metal-binding motifs have been hypothesized to have existed through analyses of extant protein sequences. However, it is unclear how metal-binding motifs might have evolved in the harsh prebiotic environment. Here, we show how certain environments, in particular seawater-like environments rich in divalent cations and especially Mg2+, support the survival of short peptides upon extreme temperatures as high as 150 °C. Moreover, while Mg2+ does not offer the same protection from UV light, peptides are protected from both heat and irradiation when bound to a metal ion. The results suggest that specific environments rich in metal ions may be better suited for the emergence of complex systems in the path toward life. Additionally, the conditional degradation of peptides depending on their ability of binding metals might have enabled a selection mechanism that would favor the survival of metal-binding motifs which resemble the motifs found in modern proteins. These short sequences could have acted as early, simple catalysts able to facilitate a restricted set of chemical reactions, which would shape the emergence and biology of the Last Universal Common Ancestor.

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Imani, Zeynab. « Le rôle d’interactions N-H···S proximales dans des peptides ». Thesis, université Paris-Saclay, 2021. http://www.theses.fr/2021UPASF015.

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Les interactions non covalentes jouent un rôle clé dans des phénomènes de la biologie chimique tel que la stabilisation de la structure tertiaire et quaternaire des protéines ou la reconnaissance entre des biomolécules tel que protéine-protéine et protéine-ligand. Parmi ces interactions, la liaison hydrogène classique de type amide NH···O=C a fait l’objet de nombreuses études approfondies. En revanche, l’étude d’autres types de liaisons hydrogène impliquant le NH de la fonction amide est plus rare. Nos travaux ont été focalisés sur l’impact d’une liaison NH···S sur les préférences conformationnelles d’amino acides soufrés et de leurs oligomères courts. Nous avons préparé un panel de dérivés protégés des amino acides soufrés non-canoniques suivants : Cys(Me) (acyclique), Attc (thiétane), Atlc (thiolane), Atc (thiane). Ces dérivés ont été caractérisés par des calculs théoriques, par spectroscopie double résonance IR/UV en phase gazeuse, par spectroscopie IR et RMN en solution, et à l’état solide. Nous avons mis en évidence pour ces quatre composés l’existence concomitante d’une liaison hydrogène NH···S inter-résidus formant une structure C6ˠ et d’une interaction NH···O=C formant une structure C5. Une succession de ces motifs combinés C5-C6ˠ stabilisants a été retrouvée dans les oligomères d’Attc. Un autre type de liaison hydrogène NH···S, cette fois-ci intra-résidu et formant une structure C5ˠ, a été caractérisé dans des dimères d’Atlc et d’Atc, associée parfois à une interaction NH···O=C formant un coude ˠ. La force de l’interaction NH···X dans le motif structural combiné C5-C6ˠ a été évaluée par comparaison avec des dérivés protégés amino acides cycliques à 4 chaînons : Attc (X = soufre), (Aatc(Me) (X = azoté), Aotc (X = oxygéné). Le motif C5-C6ˠ était présent dans les trois cas et la comparaison des spectres IR en phase gazeuse et en solution, aidée par des calculs théoriques, nous a permis de déduire une force croissante de la liaison hydrogène NH···X en allant de X=O vers X=S puis X=N
Non-covalent interactions play a key role in chemical biology phenomena such as the stabilization of protein tertiary and quaternary structure or protein-protein and protein-substrate recognition. Among these interactions, the classical amide-type NH···O=C hydrogen bond has been thoroughly studied. The study of other types of non-covalent interactions implicating peptide backbone NH groups is much rarer. This work focused on the impact of NH···S hydrogen bonding on the conformational preferences of thioether amino acid residues and their short oligomers. A panel of capped derivatives of the following non-canonical sulfur-containing amino acids was prepared: Cys(Me) (acyclic), Attc (thietane), Atlc (thiolane), Atc (thiane). These derivatives were characterized computationally, by IR/UV double resonance laser spectroscopy in the gas phase, by IR and NMR spectroscopy in solution, and in the solid state. We demonstrated the concomitant existence of inter-residue C6ˠ NH···S hydrogen bonds and C5 NH···O=C interactions in each of these four compounds. This combined stabilizing feature was also prevalent in Attc oligomers. A different intra-residue C5ˠ NH···S hydrogen bond was characterized in short oligomers of Atlc and Atc, in some cases associated with a ˠ-turn NH···O=C interaction. The significance of NH···S bonding in the combined C5-C6ˠ structural feature of Attc was evaluated by comparison with capped derivatives of other four-membered ring amino acids: Ac4c (cyclobutane), Aatc(Me) (azetidine), Aotc (oxetane). The C5–C6ˠ feature was present in the three heterocyclic residues: comparison of their IR spectra in gas phase and in solution, aided by theoretical calculations, allowed us to identify an increasing strength of NH···X hydrogen bonding from X=O to X=S to X=N

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Hadjidakis, I. « Studies relating to the ferrodoxins : The influence of synthetic peptides on the assembly of iron-sulphur clusters ». Thesis, University of Exeter, 1985. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.353046.

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Chapitres de livres sur le sujet "Sulfur Peptide"

Prütz, Walter A. « Free Radical Transfer Involving Sulphur Peptide Functions ». Dans Sulfur-Centered Reactive Intermediates in Chemistry and Biology, 389–99. Boston, MA : Springer US, 1990. http://dx.doi.org/10.1007/978-1-4684-5874-9_34.

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Nakamura, Akira, et Norikazu Ueyama. « Importance of Peptide Sequence in Electron-Transfer Reactions of Iron—Sulfur Clusters ». Dans ACS Symposium Series, 292–301. Washington, DC : American Chemical Society, 1988. http://dx.doi.org/10.1021/bk-1988-0372.ch014.

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Nakamura, Akira, et Norikazu Ueyama. « Chemical Functions of Single and Double NH---S Hydrogen Bond in Iron-Sulfur Metalloproteins ; Model Ligands with Cys-containing Peptide and Simple Acylaminobenzenethiolate ». Dans Nuclear Magnetic Resonance of Paramagnetic Macromolecules, 265–79. Dordrecht : Springer Netherlands, 1995. http://dx.doi.org/10.1007/978-94-015-8573-6_12.

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Spaltenstein, A., J. Leban, E. S. Furfine et K. D. Stewart. « Synthesis of C2-symmetric HIV-protease inhibitors with sulfur-containing central units ». Dans Peptides 1992, 933–35. Dordrecht : Springer Netherlands, 1993. http://dx.doi.org/10.1007/978-94-011-1470-7_428.

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Greiner, Georg, et Peter Hermann. « Application of penicillin amidohydrolase (PAH) for sulphur and amino deprotection in peptide synthesis ». Dans Peptides 1990, 277–78. Dordrecht : Springer Netherlands, 1991. http://dx.doi.org/10.1007/978-94-011-3034-9_117.

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Gazal, Sharon, Gary Gellerman, Ofer Ziv, Olga Karpov, Pninit Litman, Moshe Bracha, Michel Afargan et Chaim Gilon. « Human Somatostatin Receptor Specificity of Backbone-Cyclic Analogs Containing Novel Sulfur Building Units ». Dans Peptides : The Wave of the Future, 626–27. Dordrecht : Springer Netherlands, 2001. http://dx.doi.org/10.1007/978-94-010-0464-0_291.

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Abraham, E. P., et G. G. F. Newton. « Structure and Function of Some Sulphur-Containing Peptides ». Dans Ciba Foundation Symposium - Amino Acids and Peptides with Antimetabolic Activity, 205–25. Chichester, UK : John Wiley & Sons, Ltd., 2008. http://dx.doi.org/10.1002/9780470719114.ch16.

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Appleton, Trevor G. « Diammine- and Diamineplatinum Complexes with Non-Sulfur-Containing Amino Acids and Peptides ». Dans Cisplatin, 363–76. Zürich : Verlag Helvetica Chimica Acta, 2006. http://dx.doi.org/10.1002/9783906390420.ch14.

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Lee, Sang-Hyeup, Juyoung Yoon, Kensuke Nakamura et Yoon-Sik Lee. « Preparation of β-Amino-α-mercapto Acids and Amides : Stereocontrolled Syntheses of 2′-Sulfur Analogues of the Taxol C-13 Side Chain, Both syn and and S-Acetyl-N-benzoyl-3-phenylisocysteine ». Dans Peptides : The Wave of the Future, 50–51. Dordrecht : Springer Netherlands, 2001. http://dx.doi.org/10.1007/978-94-010-0464-0_19.

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Wecker, Matt, et Drew Smith. « [16] Selection for RNA : Peptide recognition through sulfur alkylation chemistry ». Dans Methods in Enzymology, 229–37. Elsevier, 2000. http://dx.doi.org/10.1016/s0076-6879(00)18055-3.

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Actes de conférences sur le sujet "Sulfur Peptide"

Mansy, Sheref. « Prebiotic iron-sulfur peptides as precursors of enzymes ». Dans Goldschmidt2021. France : European Association of Geochemistry, 2021. http://dx.doi.org/10.7185/gold2021.7211.

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Rapports d'organisations sur le sujet "Sulfur Peptide"

Cytryn, Eddie, Mark R. Liles et Omer Frenkel. Mining multidrug-resistant desert soil bacteria for biocontrol activity and biologically-active compounds. United States Department of Agriculture, janvier 2014. http://dx.doi.org/10.32747/2014.7598174.bard.

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Control of agro-associated pathogens is becoming increasingly difficult due to increased resistance and mounting restrictions on chemical pesticides and antibiotics. Likewise, in veterinary and human environments, there is increasing resistance of pathogens to currently available antibiotics requiring discovery of novel antibiotic compounds. These drawbacks necessitate discovery and application of microorganisms that can be used as biocontrol agents (BCAs) and the isolation of novel biologically-active compounds. This highly-synergistic one year project implemented an innovative pipeline aimed at detecting BCAs and associated biologically-active compounds, which included: (A) isolation of multidrug-resistant desert soil bacteria and root-associated bacteria from medicinal plants; (B) invitro screening of bacterial isolates against known plant, animal and human pathogens; (C) nextgeneration sequencing of isolates that displayed antagonistic activity against at least one of the model pathogens and (D) in-planta screening of promising BCAs in a model bean-Sclerotiumrolfsii system. The BCA genome data were examined for presence of: i) secondary metabolite encoding genes potentially linked to the anti-pathogenic activity of the isolates; and ii) rhizosphere competence-associated genes, associated with the capacity of microorganisms to successfully inhabit plant roots, and a prerequisite for the success of a soil amended BCA. Altogether, 56 phylogenetically-diverse isolates with bioactivity against bacterial, oomycete and fungal plant pathogens were identified. These strains were sent to Auburn University where bioassays against a panel of animal and human pathogens (including multi-drug resistant pathogenic strains such as A. baumannii 3806) were conducted. Nineteen isolates that showed substantial antagonistic activity against at least one of the screened pathogens were sequenced, assembled and subjected to bioinformatics analyses aimed at identifying secondary metabolite-encoding and rhizosphere competence-associated genes. The genome size of the bacteria ranged from 3.77 to 9.85 Mbp. All of the genomes were characterized by a plethora of secondary metabolite encoding genes including non-ribosomal peptide synthase, polyketidesynthases, lantipeptides, bacteriocins, terpenes and siderophores. While some of these genes were highly similar to documented genes, many were unique and therefore may encode for novel antagonistic compounds. Comparative genomic analysis of root-associated isolates with similar strains not isolated from root environments revealed genes encoding for several rhizospherecompetence- associated traits including urea utilization, chitin degradation, plant cell polymerdegradation, biofilm formation, mechanisms for iron, phosphorus and sulfur acquisition and antibiotic resistance. Our labs are currently writing a continuation of this feasibility study that proposes a unique pipeline for the detection of BCAs and biopesticides that can be used against phytopathogens. It will combine i) metabolomic screening of strains from our collection that contain unique secondary metabolite-encoding genes, in order to isolate novel antimicrobial compounds; ii) model plant-based experiments to assess the antagonistic capacities of selected BCAs toward selected phytopathogens; and iii) an innovative next-generation-sequencing based method to monitor the relative abundance and distribution of selected BCAs in field experiments in order to assess their persistence in natural agro-environments. We believe that this integrated approach will enable development of novel strains and compounds that can be used in large-scale operations.

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