Добірка наукової літератури з теми "Metal-Chelating peptides"
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Статті в журналах з теми "Metal-Chelating peptides":
1
Matsubara, Teruhiko, Yuko Hiura, and Katsuhiro Kawashiro. "Biocombinatorial Selection of Metal Ion-Chelating Peptides." International Journal of Modern Physics B 17, no. 08n09 (April 10, 2003): 1324–28. http://dx.doi.org/10.1142/s0217979203018946.
Анотація:
A phage-displayed library selection was performed to obtain metal ion-chelating peptides. A dodecamer (12-mer) random peptide library was displayed on the surface of filamentous bacterial phage and subjected to an affinity selection. Four rounds of the selection gave fourteen Zn2+-positive phage clones. Enzyme-linked immunosorbent assay showed that the selected clones specifically bound to Zn2+ and Ni2+, but not to Cu2+ and Fe3+. Deduced amino acid sequences of the clones had histidine-rich consensus motifs. These chelating peptides should be applied to designing for metal ion-trapping biomaterials.
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Lu, WeiTao, and ChunMing Dong. "Research progress of metal chelating peptides." Food and Health 4, no. 4 (2022): 19. http://dx.doi.org/10.53388/fh20221101019.
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Kani, Hatice K., Ebru K. Kocazorbaz, and Figen Zihnioglu. "Investigation and isolation of peptide based antiglycating agents from various sources." Turkish Journal of Biochemistry 44, no. 5 (October 25, 2019): 699–705. http://dx.doi.org/10.1515/tjb-2018-0294.
Анотація:
Abstract Background In this work, peptide based antiglycation agents from various sources against the advanced glycation endproducts (AGE) formation was investigated. Materials and methods As a source of peptides with deglycating activity, Glycine max, Hordeum vulgare, Triticum aestivum, Avena sativa, Prunus dulcis ve Juglans regia were used. The metal chelating activity and antioxidant activity were determined by Cu(II) chelating activity and CUPRAC (Cupric Reducing Antioxidant Capacity) methods. Antidiabetic activity was evaluated through BSA-glucose model. Results Most of the extracts obtained have inhibitory activity against AGE formation. Among all plant peptide isolates soybean was found to be most efficient by means of antiglycating (IC50 1.33 μg/mL), antioxidant (28.2 ± 1.4 μmol AAE/mg) and metal chelation activity (55%). Conclusion As a result, this study can provide preliminary data to literature to support researches those focused on peptide based glycation inhibitors and discovery of potent AGE inhibitory peptides.
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Chan, Pei-Teng, Patricia Matanjun, Cahyo Budiman, Rossita Shapawi, and Jau-Shya Lee. "Novel Peptide Sequences with ACE-Inhibitory and Antioxidant Activities Derived from the Heads and Bones of Hybrid Groupers (Epinephelus lanceolatus × Epinephelus fuscoguttatus)." Foods 11, no. 24 (December 9, 2022): 3991. http://dx.doi.org/10.3390/foods11243991.
Анотація:
The heads and bones of hybrid groupers are potential precursors for angiotensin-converting enzyme (ACE)-inhibitory and antioxidant peptides. The aim of this study was to isolate the dual-action peptides from the Alcalase-treated head and bone hydrolysate of hybrid groupers followed by identification of the novel peptides. The stability of these peptides against stimulated in vitro gastrointestinal digestion (SGID) was also determined. Fraction HB-IV (less than 1 kDa) obtained from ultrafiltration showed the strongest ACE-inhibition ability (IC50: 0.28 mg/mL), which was comparable to the potency of the commercial supplement, PeptACE (IC50: 0.22 mg/mL). This fraction also demonstrated the highest hydroxyl radical scavenging and metal-chelating activities. However, further fractionation of HB-IV by a series of chromatography resulted in peptide fractions of reduced ACE-inhibitory and antioxidant activities. The hydroxyl radical scavenging and reduction potential of HB-IV were enhanced, whereas ACE-inhibitory and metal-chelating activities were reduced following SGID. A total of 145 peptide sequences were identified from HB-IV, of which 137 peptides were novel to the BIOPEP database. The results suggested that the bioactive peptides isolated from the heads and bones of hybrid groupers could be used as functional foods/ingredients with potential ACE-inhibitory and antioxidant effects.
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Daubit, Isabelle Marie, and Nils Metzler-Nolte. "On the interaction of N-heterocyclic carbene Ir+I complexes with His and Cys containing peptides." Dalton Transactions 48, no. 36 (2019): 13662–73. http://dx.doi.org/10.1039/c9dt01338e.
Анотація:
In the interaction of an [Ir(+i)(COD)(NHC)Cl] complex with model peptides a chelating motif with a particularly interesting bimetallic peptide-bridged Ir(+iii)–NHC motif was identified with loss of the COD and Cl ligands and oxidation of the metal.
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Irankunda, Rachel, Jairo Andrés Camaño Echavarría, Cédric Paris, Loïc Stefan, Stéphane Desobry, Katalin Selmeczi, Laurence Muhr, and Laetitia Canabady-Rochelle. "Metal-Chelating Peptides Separation Using Immobilized Metal Ion Affinity Chromatography: Experimental Methodology and Simulation." Separations 9, no. 11 (November 14, 2022): 370. http://dx.doi.org/10.3390/separations9110370.
Анотація:
Metal-Chelating Peptides (MCPs), obtained from protein hydrolysates, present various applications in the field of nutrition, pharmacy, cosmetic etc. The separation of MCPs from hydrolysates mixture is challenging, yet, techniques based on peptide-metal ion interactions such as Immobilized Metal Ion Affinity Chromatography (IMAC) seem to be efficient. However, separation processes are time consuming and expensive, therefore separation prediction using chromatography modelling and simulation should be necessary. Meanwhile, the obtention of sorption isotherm for chromatography modelling is a crucial step. Thus, Surface Plasmon Resonance (SPR), a biosensor method efficient to screen MCPs in hydrolysates and with similarities to IMAC might be a good option to acquire sorption isotherm. This review highlights IMAC experimental methodology to separate MCPs and how, IMAC chromatography can be modelled using transport dispersive model and input data obtained from SPR for peptides separation simulation.
7
Luisi, Grazia, Azzurra Stefanucci, Gokhan Zengin, Marilisa Dimmito, and Adriano Mollica. "Anti-Oxidant and Tyrosinase Inhibitory In Vitro Activity of Amino Acids and Small Peptides: New Hints for the Multifaceted Treatment of Neurologic and Metabolic Disfunctions." Antioxidants 8, no. 1 (December 26, 2018): 7. http://dx.doi.org/10.3390/antiox8010007.
Анотація:
Oxidative damage is among the factors associated with the onset of chronic pathologies, such as neurodegenerative and metabolic diseases. Several classes of anti-oxidant compounds have been suggested as having a protective role against cellular stressors, but, in this perspective, peptides’ world represents a poorly explored source. In the present study, the free radical scavenging properties, the metal ion reducing power, and the metal chelating activity of a series of sulfurated amino acids and tripeptides were determined in vitro through canonical assays (DPPH, ABTS, CUPRAC, FRAP, PM, and EECC) and estimated in comparison with the corresponding activities of synthetic peptide semicarbazones, incorporating the peculiar non-proteinogenic amino acid, tert-leucine (tLeu). The compounds exhibited remarkable anti-oxidant properties. As expected, sulfurated compounds 1–5 were found to be the most efficient radical scavengers and strongest reductants. Nevertheless, tLeu-containing peptides 7 and 8 disclosed notable metal reducing and chelating activities. These unprecedented results indicate that tLeu-featuring di- and tripeptide backbones, bearing the semicarbazone chelating moiety, are compatible with the emergence of an anti-oxidant potential. Additionally, when tested against a panel of enzymes usually targeted for therapeutic purposes in neurodegenerative and metabolic disorders, all samples were found to be good inhibitors of tyrosinase.
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Fisher, A. E. O., and D. P. Naughton. "Metal ion chelating peptides with superoxide dismutase activity." Biomedicine & Pharmacotherapy 59, no. 4 (May 2005): 158–62. http://dx.doi.org/10.1016/j.biopha.2005.03.008.
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Gallegos Tintoré, Santiago, Cristina Torres Fuentes, Javier Solorza Feria, Manuel Alaiz, Julio Girón Calle, Alma Leticia Martínez Ayala, Luis Chel Guerrero, and Javier Vioque. "Antioxidant and Chelating Activity of NontoxicJatropha curcasL. Protein Hydrolysates Produced byIn VitroDigestion Using Pepsin and Pancreatin." Journal of Chemistry 2015 (2015): 1–9. http://dx.doi.org/10.1155/2015/190129.
Анотація:
The antioxidant and metal chelating activities inJ. curcasprotein hydrolysates have been determined. The hydrolysates were produced by treatment of a nontoxic genotype with the digestive enzymes pepsin and pancreatin and then were characterized by fast protein liquid chromatography and reverse phase chromatography. Peptidic fractions with higher radical scavenging activity were analysed by matrix-assisted laser desorption/ionization mass spectrometry. The antioxidant activity was determined by measuring inhibition of the oxidative degradation ofβ-carotene and by measuring the reactive oxygen species (ROS) in Caco-2 cell cultures. Cu2+and Fe2+chelating activities were also determined. The hydrolysates inhibited the degradation ofβ-carotene and the formation of ROS in Caco-2 cells. The lower molecular weight peptidic fractions from FPLC had stronger antioxidant activity in cell cultures compared with the hydrolysates, which correlated with a higher content in antioxidant and chelating amino acids. These fractions were characterized by a large presence of peptides with different molecular masses. The hydrolysates exhibited both Cu2+and Fe2+chelating activity. It was concluded thatJ. curcasis a good source of antioxidant and metal chelating peptides, which may have a positive impact on the economic value of this crop, as a potential source of food functional components.
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Irankunda, Rachel, Jairo Andrés Camaño Echavarría, Cédric Paris, Katalin Selmeczi, Loïc Stefan, Sandrine Boschi-Muller, Laurence Muhr, and Laetitia Canabady-Rochelle. "Deciphering Interactions Involved in Immobilized Metal Ion Affinity Chromatography and Surface Plasmon Resonance for Validating the Analogy between Both Technologies." Inorganics 12, no. 1 (January 16, 2024): 31. http://dx.doi.org/10.3390/inorganics12010031.
Анотація:
Various peptides can be obtained through protein enzymatic hydrolysis. Immobilized metal ion affinity chromatography (IMAC) is one of the methods which can be used to separate metal chelating peptides (MCPs) in a hydrolysate mixture. In this context, this work aims to understand deeply the interactions in IMAC and surface plasmon resonance (SPR) in order to validate experimentally the analogy between both technologies and to be further able to perform IMAC modeling in the next work using peptide sorption isotherm parameters obtained from SPR. Indeed, chromatography modeling can be used to predict separation of MCPs in IMAC and the knowledge of peptide sorption isotherm obtained from SPR is a crucial step. For this purpose, 22 peptides were selected and investigated in IMAC using HisTrap X-Ni2+ and HiFliQ NTA-Ni2+ columns and were also studied in SPR as well. Results showed that peptides with histidine residues had good affinity to Ni2+, while the high positive charge of peptides was responsible of ionic interactions. Further, most of the peptides with good retention time in IMAC showed a good affinity in SPR as well, which validated experimentally the SPR-IMAC analogy.
Дисертації з теми "Metal-Chelating peptides":
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El, Hajj Sarah. "Methodologies for Screening Metal-Chelating Peptides in Protein Hydrolysates for their Antioxidant Properties." Electronic Thesis or Diss., Université de Lorraine, 2022. http://www.theses.fr/2022LORR0031.
Анотація:
Actuellement, la découverte de nouvelles biomolécules est primordiale pour diverses applications industrielles. Les peptides produits par hydrolyse de protéines végétales ou animales, présentent un intérêt en raison de leurs bioactivités potentielles. Certains peptides, par leur capacité à complexer le fer(II), peuvent inhiber les phénomènes d’oxydation. À ce jour, la découverte de nouvelles molécules bioactives est généralement basée sur des approches empiriques longues, et fastidieuses. Par conséquent, il est important de développer de nouvelles méthodes de criblage très sensibles avant de mettre en place un procédé de séparation sélectif de ces peptides d’intérêt présents en mélange. L’objectif de cette thèse est donc de (1) développer des méthodes de criblage à haute sensibilité pour identifier la présence de ces peptides chélateurs de métaux (PCMs) dans les hydrolysats, produits en laboratoire, avant d’entreprendre une phase séparative chronophage et (2) d’étudier leurs activités antioxydantes, à l’aide de tests biochimiques et cellulaires. Dans une première approche, ces PCM ont été criblés dans les hydrolysats de protéines de soja en utilisant une approche par Résonance Plasmonique de Surface (SPR). Cette technique permet de déterminer une constante d’affinité entre un peptide et un ion métallique immobilisé sur une micro-puce à l’échelle moléculaire. Elle est utilisé ici pour étudier différents hydrolysats et ainsi cribler la meilleure condition d'hydrolyse pour produire des PCMs. Avec ce même objectif, la dynamique moléculaire à résolution temporelle (switchSENSEⓇ) constitue une seconde approche basée sur un biocapteur et un suivi de fluorescence. Cette technologie est basée sur le mouvement électrique d'ADN, présents en surface de microélectrodes, sur lesquels sont immobilisés des ions métalliques immobilisés. Lorsqu’un peptide forme un complexe peptide-métal, cela entraîne une variation du signal de fluorescence mesuré. Cette méthode a d'abord été mise en place sur des PCMs de synthèse modèles, puis appliquée sur des hydrolysats de protéines de soja et Tilapia. Elle s’avère d’une très grande sensibilité pour détecter la présence de PCMs dans des hydrolysats. L'intérêt biologique d'explorer l'activité chélatrice de métaux dans ces hydrolysats est d'évaluer leur pouvoir antioxydant in cellulo. Ces peptides pourraient être prometteurs pour l'inhibition de la ferroptose en chélatant l'excès d'ion fer et ainsi contribuer à la prévention de la mort cellulaire dans plusieurs maladies dont l'athérosclérose (AS). Nous avons voulu développer un modèle de ferroptose (induction et sauvetage) sur des cellules musculaires aortiques humaines pour imiter la ferroptose qui se produit pendant le développement de l'AS. Le modèle de ferroptose a été développé en trois étapes en prenant en considération trois paramètres essentiels tels que la concentration des inducteurs de ferroptose (Erastin et ions ferriques), le temps et le milieu d'incubation. À chaque étape, 2 biomarqueurs, à savoir la concentration intracellulaire de GSH et la peroxydation lipidique, ont été suivis par les méthodes NDA et TBARS, respectivement. Enfin, le modèle de ferroptose a été validé lors d'une incubation de 10 µM d'Erastin et 50 µM d'ions ferriques pendant 1 nuit dans un milieu complet dilué 2 fois. L'Erastin a réussi à bloquer le système Xc- conduisant à la déplétion de la cystéine intracellulaire nécessaire à la synthèse du GSH. L'ajout d'ions ferriques a accéléré les réactions oxydatives, produisant des espèces réactives qui ont attaqué les membranes lipidiques des cellules et provoqué une peroxydation lipidique. Le sauvetage du modèle de ferroptose a été validé en utilisant des chélateurs de métaux tels que le DFO et le DFr, qui sont également des contrôles de l'activité des MCP. Seul la DFr à 150 µM a été capable d'inhiber la peroxydation lipidique provoquée par l'Erastin et l'ion ferriqueCurrently, the discovery of new biomolecules is essential for various industrial applications. Peptides produced by hydrolysis of plant or animal proteins are of interest because of their potential bioactivities. Some peptides, by their ability to complex iron(II), can inhibit and slow down oxidation phenomena. To date, the discovery of new bioactive molecules is generally based on long and fastidious empirical approaches, involving large quantities of solvents, harmful to the environment. Therefore, it is important to develop new and highly sensitive screening methods before implementing a selective separation process of these peptides of interest present in mixture. The objective of this thesis is therefore to (i) develop highly sensitive screening methods to identify the presence of these metal chelating peptides (MCPs) in hydrolysates, produced in the laboratory, before undertaking a time-consuming separation phase and (2) to study their antioxidant activities, using biochemical and cellular assays. In the first approach, time-resolved molecular dynamics (switchSENSE) was first implemented on model peptides capable of complexing metals and then applied to non-filtrated soy and tilapia protein hydrolysates. It has proven to be very sensitive for detecting the presence of MCPs in peptide hydrolysates. This technology is based on the electrical movement of DNA strands, present on the surface of gold microelectrodes, on which are immobilized metal ions. When a peptide has an affinity for an immobilized metal ion and thus forms a peptide-metal complex, this results in a variation of the measured fluorescence signal. On the other hand, MCPs were screened in ultrafiltrated soy and pea protein hydrolysates using Surface Plasmon Resonance (SPR). This advanced technique, allows to determine an affinity constant between a peptide and a metal ion immobilized on a microchip at the molecular scale. It is used here in an original way to study different hydrolysates and thus screen the best hydrolysis condition to produce MCPs. The biological interest in exploring metal-chelating activity in these hydrolysates is to evaluate their antioxidant power in cellulo. These peptides could be promising for ferroptosis inhibition by chelating excess iron ions and thus contribute to the prevention of cell death in several diseases including Atherosclerosis (AS). We aimed to develop a ferroptosis model (induction and rescuing) on human aortic smooth muscle cells to mimic ferroptosis happening during AS development. The ferroptosis model was developed in three steps taking into consideration three essential parameters such as the concentration of ferroptosis inducers (Erastin and ferric ions), the time and the medium of incubation. At each step, 2 biomarkers i.e. intracellular concentration of GSH and lipid peroxidation were followed by NDA and TBARS methods, respectively. The rescue of the ferroptosis model was validated using metal chelators such as DFO and DFr, which are also control molecule regarding MCP activity
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Irankunda, Rachel. "Nickel Chelating Peptides & Chromatography : From Peptides Separation Simulation up to their Antioxidant Activities - related Applications." Electronic Thesis or Diss., Université de Lorraine, 2023. http://www.theses.fr/2023LORR0213.
Анотація:
Les peptides chélateurs de métaux (PCMs), issus d'hydrolysats de protéines, présentent diverses applications dans les domaines de la nutrition, de la pharmacie, des cosmétiques, etc. Cependant, l'approche empirique généralement utilisée pour découvrir des peptides bioactifs à partir d'hydrolysats est longue et coûteuse en raison de nombreuses étapes de fractionnement, de séparation et d'évaluation des activités biologiques. Cette thèse a donc pour but de développer une nouvelle approche pour la prédiction de la séparation des PCMs en utilisant la modélisation et la simulation chromatographiques basées sur l'analogie entre la chromatographie d'affinité sur ions métalliques immobilisés (IMAC) et la résonance plasmonique de surface (SPR). Pour la première fois, l'analogie SPR-IMAC a été étudiée expérimentalement sur 22 peptides et 70% d'entre eux ont validé cette analogie, puisque les peptides bien retenus en IMAC étaient également dotés d'une bonne affinité pour Ni2+ en SPR. Dans un deuxième temps, des peptides ayant une forte affinité pour Ni2+ (c'est-à-dire une faible constante de dissociation KD en SPR et un temps de rétention élevé en IMAC) ont été utilisés pour étudier la simulation des profils de concentration de peptides à la sortie de la colonne en IMAC. La connaissance des isothermes d'adsorption étant nécessaire pour effectuer la simulation, il a fallu développer une méthodologie pour prédire les paramètres de l'isotherme de Langmuir en IMAC à partir des données SPR. La simulation a été évaluée en comparant les temps de rétention expérimentaux et simulés qui devraient être proches pour une prédiction fiable. Par conséquent, plusieurs approches ont été étudiées pour déterminer les paramètres de sorption de Langmuir. L‘approche la plus intéressante a introduit un facteur correctif sur la capacité d'adsorption maximale qmax seulement. En effet, l'affinité des peptides pour le Ni2+ immobilisé étant supposée constante quelle que soit technologie utilisée (SPR vs. IMAC), la constante d'affinité KA n'a pas été modifiée. Parallèlement, les applications industrielles des PCMs et des hydrolysats peptidiques ont été étudiées. Tout d'abord, des hydrolysats de protéines de pois ont été produits par protéolyse enzymatique soit avec l'Alcalase® suivi de la Flavourzyme® (Alc+Flav≤1kDa), soit par la Protamex® suivi de la Flavourzyme® (Prot+Flav≤1kDa). La technologie SwitchSENSE® a mis en évidence la présence de peptides chélateurs de Ni2+ et les tests antioxydants ont montré que l'hydrolysat Prot+Flav≤1kDa avait une activité antiradicalaire et un pouvoir réducteur plus élevés, liés à son degré d'hydrolyse plus élevé et à la quantité de peptides de petite taille. Les hydrolysats de protéines de pois et les PCMs ont ensuite été étudiés pour leur capacité à inhiber l'oxydation des lipides dans les émulsions. Ils ont ralenti l'oxydation des lipides par chélation des métaux pro-oxydants (tels que Fe2+) en réduisant les produits d'oxydation primaires et secondaires, responsables de la détérioration des produits contenant des lipides. Ainsi, les hydrolysats de pois et les PCMs pourraient être utilisés comme antioxydants dans les produits alimentaires et cosmétiques, comme alternatives aux produits chimiques tels que l'EDTA, le BHT et le TBHQMetal-Chelating Peptides (MCPs), from protein hydrolysates, present various applications in nutrition, pharmacy, cosmetic etc. Yet, the empirical approach generally used to discover bioactive peptides from hydrolysates is time consuming and expensive due to many steps of fractionation, separation and biological activities evaluation. Thus, this PhD aimed to develop a novel approach for MCPs separation prediction using chromatography modelling and simulation based on the analogy between Immobilized Metal ion Affinity Chromatography (IMAC) and Surface Plasmon Resonance (SPR). For the first time, the SPR-IMAC analogy was experimentally investigated on 22 peptides and 70% of them validated this analogy, since peptides well retained in IMAC were also endowed with a good affinity for Ni2+ in SPR. In the second time, peptides with high affinity for Ni2+ (i.e low dissociation constant KD in SPR and a high retention time in IMAC) were used to study the modelling and simulation of peptide concentration profiles at the column outlet in IMAC. Since knowledge of adsorption isotherms was required to perform simulation, it was necessary to develop a methodology for predicting Langmuir isotherm parameters in IMAC from SPR data. The validity of simulation was evaluated by comparing experimental and simulated retention times that should be close for reliable prediction. Therefore, several approaches were evaluated to determine Langmuir sorption parameters, the most interesting one introduces a correction factor on the maximum adsorption capacity qmax alone, assuming that the affinity of peptides for immobilized Ni2+ did not change depending on the technology used (SPR vs. IMAC), thus affinity constant KA was not modified. Meanwhile, industrial application of MCPs and hydrolysates were studied. First, pea protein hydrolysates were produced by either Alcalase® followed by Flavourzyme® (Alc+Flav≤1kDa) or Protamex® followed by Flavourzyme® (Prot+Flav≤1kDa). SwitchSENSE® technology evidences the presence of Ni2+ chelating peptides and antioxidants tests showed that Prot+Flav≤1kDa has higher radical scavenging and reducing power, related to its higher degree of hydrolysis and small-size peptides quantity. Secondly, pea hydrolysates and MCPs were investigated for their ability to inhibit the lipid oxidation in emulsions. They slowed down lipid oxidation through chelation of prooxidant (metals such as Fe2+) reducing primary and secondary oxidation products responsible of deterioration of lipid containing products. Thus, pea hydrolysates and MCPs could be used as antioxidants in food and cosmetic products, as alternative to chemicals such as EDTA, BHT and TBHQ
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Paris, Cédric. "Développement de nouvelles approches analytiques pour le criblage de peptides chélateurs de fer." Electronic Thesis or Diss., Université de Lorraine, 2021. http://www.theses.fr/2021LORR0088.
Анотація:
Face au besoin croissant de nouvelles molécules bioactives d’origine naturelle, les coproduits de l’industrie alimentaire et de transformation d’agroressources constituent une ressource stratégique à exploiter. En effet, l’hydrolyse enzymatique de protéines végétales ou animales permet de générer une grande variété de séquences peptidiques avec des propriétés biologiques potentielles : antihypertensive, antithrombotique, anticancéreuse, opioïde, antimicrobienne. Malgré le potentiel bioactif de certains peptides, leur présence incertaine et leur faible concentration au sein d’un hydrolysat protéique (mélange complexe constitué d’une dizaine à parfois plus d’une centaine de peptides) limitent leur purification et leur exploitation. Aussi, les peptides bioactifs pourraient être criblés préalablement à toute phase séparative afin de n’engager l’étape de séparation qu’en cas d’activité avérée. Le pouvoir antioxydant est un terme générique qui regroupe divers mécanismes chimiques tels que l’activité anti-radicalaire, l’inhibition de la peroxydation des lipides, ou encore la chélation de métaux. En chélatant les métaux de transition naturellement présents in vivo (fer, cuivre), les peptides chélateurs pourraient être utilisés comme antioxydants indirects et agir ainsi contre le stress oxydant. L’objectif principal de cette thèse est de développer des méthodes originales de criblage à haut débit des peptides chélateurs de fer présents dans des hydrolysats peptidiques. A terme, ces méthodes pourraient être appliquées à tous types de mélanges peptidiques complexes. La première approche développée met en œuvre la chromatographie d'affinité pour ions métalliques immobilisés (IMAC). Cette technique est incontournable pour purifier des peptides chélateurs de métaux au sein des hydrolysats. Grâce à la spécificité d’interaction entre un métal donné – immobilisé sur la phase stationnaire IMAC – et des motifs complexants déterminés, il est possible d’identifier sélectivement les composés chélateurs présents dans des mélanges complexes. Notre objectif étant de parvenir à une détection rapide de ces molécules d’intérêt, nous avons réalisé un couplage en ligne avec la spectrométrie de masse (MS). La deuxième stratégie consiste à évaluer la formation des complexes fer-peptide en solution. Dans ce cas, tous les sites accepteurs d’électrons du métal sont accessibles (au contraire de la technique IMAC qui présente un biais potentiel de ce point de vue) et, d’autre part, les conditions de solubilisation peuvent simuler le milieu visé (i.e. le milieu intracellulaire). Par ailleurs, l’observation de la forme complexée avec le fer (FeII ou FeIII) fournit une preuve directe et irréfutable de la capacité de chélation d’un peptide. Ainsi, la mise en évidence d’un peptide chélateur peut être réalisée par détection concomitante de sa forme libre (peptide seul) et de sa forme complexée (fer-peptide). Dans cette approche, la spectrométrie de masse – de par sa sensibilité et sa spécificité – est une technique de choix pour réaliser le criblage souhaité. Après avoir été testés sur des peptides des synthèse (sous forme pure et en mélange), les deux protocoles ont été appliqués à un hydrolysat protéique réel. Les résultats préliminaires obtenus sont prometteurs et permettent d'envisager, à court terme, le criblage automatisé de divers hydrolysats réels, pour la recherche de peptides chélateurs du fer(II) et du fer(III)Faced with the growing need for new bioactive compounds of natural origin, by-products from the agro-food industry and the processing of agro-resources constitute a strategic resource to be exploited. In fact, the enzymatic hydrolysis of plant or animal proteins makes it possible to generate a wide variety of peptide sequences with potential biological properties: antihypertensive, antithrombotic, anticancer, opioid, antimicrobial. Despite the bioactive potential of certain peptides, their uncertain presence and their low concentration in a protein hydrolysate (a complex mixture sometimes made up of more than a hundred peptides) limit their purification and use. Also, bioactive peptides could be screened before their purification in order to initiate the separation step only if activity is proven. Antioxidant power is a generic term which groups together various chemical mechanisms such as anti-free radical activity, inhibition of lipid peroxidation, or even metal chelation. By chelating the transition metals naturally present in vivo (iron, copper), the chelating peptides could be used as indirect antioxidants and thus act against oxidative stress. The main objective of this PhD thesis is to develop original methods for high throughput screening of iron-chelating peptides present in protein hydrolysates. Ultimately, these methods could be applied to all types of complex peptide mixtures. The first approach is based on immobilized metal affinity chromatography (IMAC). IMAC is a reference technique for purifying metal-chelating peptides in hydrolysates. Thanks to the specificity of interaction between a given metal – immobilized on the stationary phase IMAC – and determined complexing groups, it is possible to selectively identify the chelators present in complex mixtures. Our objective being to achieve a rapid detection of these molecules of interest, we carried out an on-line coupling with mass spectrometry (MS). The second strategy consists of evaluating the formation of iron-peptide complexes in solution. In this case, all the electron acceptor sites of the metal are accessible (unlike the IMAC technique which presents a potential bias from this point of view) and, on the other hand, the solubilization conditions can simulate the target medium (i.e. the intracellular medium). In addition, the observation of the peptidic form complexed with iron (FeII or FeIII) provides direct and irrefutable proof of the chelating capacity of a peptide. Thus, the identification of a chelating peptide can be carried out by the concomitant detection of its free form (peptide) and of its complexed form (iron-peptide). In this approach, mass spectrometry – thanks to its sensitivity and its specificity - is a technique of choice for carrying out the desired screening. After having been tested on synthetic peptides (pure solutions and mixture), the two protocols were applied to a real protein hydrolysate. The preliminary results are promising and make it possible to envisage, in the short term, the automated screening of various real hydrolysates for the search for iron(II)- and iron(III)-chelating peptides
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顏碧秀. "The Use of Atomic Adsorption Spectrometry for the Determination of Metal Nanoparticles and the Interaction of Metal Ions with Chelating Peptides." Thesis, 2001. http://ndltd.ncl.edu.tw/handle/44868514629154878842.
Анотація:
碩士國立中正大學
化學研究所
89
The first part of the thesis is elemental analysis of gold nanoparticles by graphite atomic absorption spectrometry. The aim is to establish the calibration curves of aqueous standards and to measure the gold nanoparticles in nonaqueous sample. The search of optimized conditions for gold nanoparticles is performed first. The use of palladium and magnesium nitrate as a matrix modifier can increase the char and atomization temperature and reduce the matrix interference. This leads to an increase in sensitivity of the determination. The surfaces of ashed gold nanoparticles were observed by atomic force microscopy to examine the ash temperature effect on the gold nanoparticles. The result indicates that the size of the gold nanoparticles do not effect the analysis. Slurry sampling technique is used for gold nanoparticle immobilized to silica. The accuracy of the determinations were confirmed by standard addition method. The sensitivity and detection limit were 30.0pg and 1.5ppb, respectively. It corresponds to the number of 2.7×105 gold particles. The RSD of the determination is poor. This is due to inhomogeneous distribution of gold particles on silica. The 2nd part of this thesis presents the preliminary results of metal ions chelation with peptides by batch and column method. The primary focus is on the selectivity, capacity and mechanism for different metal ionschelation with peptides. Copper bounds strongly to peptide3 (lysine-cysteine-βamino acid)and peptide4(glycine-cysteine- histidine) with the increase of pH value. The capacity of copper to peptide3 was 3.01mg/g by the batch method and 2.42 mg/g by the column method. For peptide3, nickel breaks through the column faster than copper and silver due to the low affinity. The adsorption mechanism is contributed to NH2 and CO-N-R for peptide3, and by NH2 , CO-N-R,and COO－for peptide4 at pH=5.5. The advantages of using the column method are better accuracy for the evalution of loading capacity and the potential for the prediction of adsorption mechanism.
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陳愷悌. "Preparation, Purification, and Immobilization of Schistosoma Japonicum Glutathions-S-transferase Tagged with a Metal Chelating Peptide." Thesis, 1998. http://ndltd.ncl.edu.tw/handle/46328224893948298568.
Анотація:
碩士國立臺灣科技大學
化學工程技術研究所
86
Application of a metal affinity tag constituted of six histidines, 6xHis tag, in immobilized metal affinity chromatography (IMAC) could simplify and integrate the purification and immobilization of recombinant protein together. We have engineered the 6xHis tag to the C-terminus of Schistosoma japonicum glutathione-S-transferase (GST) and created a fustion protein GST/His. The production, activtity, purity, proteolysis, and metal affinity of GST/His were extensively studied, as well as solid state refolding of GST/His The results showed that: (1) GST/His expression using using T7 promoter was better produced than GST expression using tac promoter. (2)The 6xHis tag had no effect on the activity and immunity of GST. (3) The optimization condition to purify GST/His with Ni2+-NTA gel was to include 20 mM imidazole in native washing buffer and 10 mM imidazole in denatruing washing buffer. Beause TALON get had better specificity to GST/His than to GST, no imidazole was required in either washing buffer. (4)The optimal immobilization concentration of GST/His on Ni2+-NTA gel was 5~50 駪/ml, resulting the best specific activity. (5)After storage at either 4℃ or 25℃ for one month, the specific activity of immobilized GST/His did not decay. However, the specific activity of immobilized GST/His decayed 60% after 50 days storage at 25℃. (6)We could recove and purify GST/His from inclusion bodies by solid state refolding procedure, where remove of high concentration of denaturing agent was performed stepwise with GST/His immobilized on Ni2+-NTA gel. (7)The proteolysis of the free form of GST/His began from the C-terminus, while that of immobilized GST/His began from the N-terminus.
Книги з теми "Metal-Chelating peptides":
1
Arya, Rajiv. DEsign and Synthesis of a metal chelating peptide. Ottawa: National Library of Canada, 1995.
Частини книг з теми "Metal-Chelating peptides":
1
Sheldon, K. M., R. Arya, and J. Gariépy. "Novel radioimmunoconjugates containing a bifunctional metal chelating peptide." In Peptides, 852–53. Dordrecht: Springer Netherlands, 1994. http://dx.doi.org/10.1007/978-94-011-0683-2_285.
2
Sanità Di Toppi, L., M. N. V. Prasad, and S. Ottonello. "Metal Chelating Peptides and Proteins in Plants." In Physiology and Biochemistry of Metal Toxicity and Tolerance in Plants, 59–93. Dordrecht: Springer Netherlands, 2002. http://dx.doi.org/10.1007/978-94-017-2660-3_3.
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Fournié-Zaluski, M. C., C. Z. Dong, Y. S. Yang, N. Jullian, and B. P. Roques. "Synthesis, conformational analysis by 1H NMR spectroscopy and metal chelating properties of a cyclic zinc finger derived from the nucleocapsid NCp7 of the human retrovirus HIV-1." In Peptides 1994, 535–36. Dordrecht: Springer Netherlands, 1995. http://dx.doi.org/10.1007/978-94-011-1468-4_242.
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Smith, Michele C., James A. Cook, Thomas C. Furman, Paul D. Gesellchen, Dennis P. Smith, and Hansen Hsiung. "Chelating Peptide-Immobilized Metal-Ion Affinity Chromatography." In ACS Symposium Series, 168–80. Washington, DC: American Chemical Society, 1990. http://dx.doi.org/10.1021/bk-1990-0427.ch012.
Тези доповідей конференцій з теми "Metal-Chelating peptides":
1
Bjørlie, Mads, Rachel Irankunda, Jean-Michel Girardet, Sandrine Boschi-Müller, Betül Yesiltas, Charlotte Jacobsen, and Laetitia Canabady-Rochelle. "Screening of Metal-chelating Peptides and Hydrolysates Using Surface Plasmon Resonance and Switchsense." In 2022 AOCS Annual Meeting & Expo. American Oil Chemists' Society (AOCS), 2022. http://dx.doi.org/10.21748/zszk2778.
Анотація:
Abstract: Lipid oxidation is, among other factors, catalyzed by the presence of metal ions and efficient metal chelators are therefore highly sought after in the food industry. Among these, natural metal chelators are gaining interest as opposed to their synthetic counterparts such as EDTA. Traditional screening for metal chelation capacity is time consuming and non-specific. The aim of this study was to screen potato protein hydrolysate and synthetic peptides derived from potato protein sequences for their metal-chelating capacity. Seven peptides and two hydrolysates (raw and ultra-filtrated) were studied. Peptides were selected using two different models: an empirical-based bioinformatics approach (AnOxPePred) and a theoretically based model for metal chelation. Surface Plasmon Resonance (SPR) is a label-free, optical technique used to determine the dissociation constant (KD) of a complex formed between immobilized Ni2+ and peptides. The SwitchSENSE technology is another approach used to study Ni2+/peptide affinity. It utilizes the quenching of fluorescence of a fluorophore upon Ni2+ immobilization and the inverse fluorescence increase upon peptide binding onto Ni2+. Both analyses were carried out at pH 7.4. In this study, we successfully determined the dissociation constants (KD) of two peptides (ASH and DHGPKIFEPS) using SPR. These values compare favourably with previous results indicating metal chelating potential. The association rate constant (kon) of all peptides were determined using switchSENSE. Yet, due to bad fitting of the kinetics data obtained with switchSENSE, the KDs of the hydrolysates were only determined with low accuracy.
2
Kaugarenia, Nastassia, Sophie Beaubier, Erwann Durand, François Lesage, Xavier Framboisier, Arnaud Aymes, Pierre Villeneuve, and Romain Kapel. "Optimization of Potent Mineral Chelating Peptides Production from Rapeseed Meal Proteins Proteolysis and Peptide Characterizations." In 2022 AOCS Annual Meeting & Expo. American Oil Chemists' Society (AOCS), 2022. http://dx.doi.org/10.21748/ougk6662.
Анотація:
Preventing lipid oxidation and microbial spoilage are both major concerns in sectors such as food and cosmetic industries. Biopeptides, arouse great interest to substitute synthetic antioxidants. Some plant proteins, like 2S rapeseed albumins are known presenting antimicrobial properties. In this context, we aimed to valorize total rapeseed meal proteins with controlled enzymatic proteolysis to generate mineral chelating peptides from the 11S globulins fraction while keeping intact the albumins fraction. To do so, screening of proteases on total rapeseed protein isolate was implemented highlighting a globulin-selective hydrolysis with Prolyve®. Ultrafiltration was then used to purified albumins and enrich the peptide fraction. The fraction obtained showed a noteworthy metal chelating activity. Then, the selected proteolysis was optimized in order to maximize the albumins purity and yield. For that, enzymatic mechanism identification in a wide operating conditions area was led to define the DoE. Then, simulation of hydrolysis kinetics was driven to predict protein fractions concentration at any time and any set of operation conditions. The obtained models were implemented in a genetic-evolutionary algorithm to generate the Pareto Front and Domain, presenting the targeted economical compromises. One solution was chosen and the identified corresponding operating conditions proved the metal chelating activity conservation (EC50 = 247 ± 27 µg) for three times faster production at the same enzyme cost. Finally, peptide activity was investigated in oil-in-water emulsion systems and compared with EDTA. Results showed that peptides could be as effective as EDTA to avoid primary and secondary lipid oxidation products formation.This work demonstrates an original total valorization of both rapeseed meal proteins in food applications. First, antioxidant peptides produced from the globulin fraction, could be used as food preservative in oil-in-water emulsion systems, but also as preventing agents for micronutrient deficiencies. And, the purified albumin fraction could be used to prevent microbial spoilage.
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Durand, Erwann, Nastassia Kaugarenia, Nathalie Barouh, Pierre Villeneuve, and Romain Kapel. "Antioxidant chelating peptides production from Rapeseed meal proteins proteolysis." In 2022 AOCS Annual Meeting & Expo. American Oil Chemists' Society (AOCS), 2022. http://dx.doi.org/10.21748/whcd7145.
Анотація:
The oxidative chemical degradation produced by reactive species (free radicals, oxygen, etc.) is responsible for the deterioration of most of the formulated products. One of the main properties of an antioxidant lies in its capacity to limit the chemical propagation of oxidation by reducing free radicals. Another strategy to prevent oxidation is binding transition metals, since they are ubiquitous and deeply involved in the initiation and propagation of lipids oxidation. Naturally occurring phospholipids, polyphenols, proteins, or peptides that can bind metal ions could be more valued than synthetic molecules, for human wellbeing, but also to align with consumer preferences. Yet, EDTA salts and sodium citrate remain the most common metal chelators in foods. In this study, we went to investigate a strategy to develop naturally produced antioxidants peptides from edible plant biomass, such as rapeseed. Several enzymatic hydrolyses of total rapeseed protein isolate with various proteases have been performed, and the produced peptides were screened for their antioxidant capacity. Peptides generated with Prolyve® allowed for particularly high Fe2+ chelation capacity (EC50 = 247 ± 27 µg). Accordingly, the enzymatic processing step with Prolyve® was modeled and optimized to minimize reaction costs and maximize peptide recovery. Then, lipid oxidation was studied in the presence or in the absence of chelating peptides, in micellar, bulk, and oil-in-water emulsion systems, and compared with EDTA salts and sodium citrate. Results clearly emphasized a very interesting potential from the peptides sample to prevent lipid oxidation by chelation of transition metals in emulsified models.This result is particularly important to develop the potential of applications of rapeseed meal in various food formulations. In addition, this study emphasized an approach aiming at developing food chelator peptides from plant proteins, having multifunctional properties, and through sustainable processing.
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Jacobsen, Charlotte, Ann-Dorit Moltke Sorensen, and Dimitra Marinou. "Enzymatic production of antioxidative and antimicrobial hydrolysates from cod solid side-streams." In 2022 AOCS Annual Meeting & Expo. American Oil Chemists' Society (AOCS), 2022. http://dx.doi.org/10.21748/qmqf3129.
Анотація:
In the last decade, there has been an increased focus and interest in increasing the utilization of existing raw materials and reducing waste especially due to the increasing global population. In the cod filleting industry up to 60% (w/w) of the biomass end up as side-streams e.g., frame, head and gut, which are either used as low value products such as animal feed or are wasted. An example of animal feed is mink feed. However, in Denmark the mink production is closed due to COVID-19 and new utilization possibilities are needed. The cod side-stream used in this study is from Royal Greenland and is very fresh with the possibility of freezing right after production to maintain quality and increase shelf life before further production. Cod frames still contain meat after filleting and could be used as hydrolysates with bioactive properties such as antioxidative and/or antimicrobial activity for food or feed applications. Previous studies have shown that longer peptides (shorter hydrolysis time) potentially have antimicrobial properties and shorter peptides (longer hydrolysis time) have antioxidative properties. Therefore, an experiment was designed using three different types of proteases (Alcalase, Neutrase and Protamex) and different hydrolysis time (½h, 1, 2, 3 and 6h) to produce different hydrolysates. Produced hydrolysates were evaluated for their antioxidative and antimicrobial activities by in vitro antioxidant assay, radical scavenging (DPPH) and metal chelating activity, and by disc diffusion and minimal inhibitory concentration (MIC) assays, respectively. Furthermore, the hydrolysates were also characterized with respect to yield, protein content and degree of hydrolysis. The produced hydrolysates showed antioxidant properties. Highest DPPH activity was obtained with Protamex, where-as highest metal chelating activity surprisingly was obtained for a control (no enzyme added). Unfortunately, no antimicro-bial activity was detected for the produced hydrolysates independent of enzymes and hydrolysis time applied. BBI JU-funded WASEABI project.
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Yesiltas, Betul, Charlotte Jacobsen, Egon B. Hansen, Michael Overgaard, Paolo Marcatili, Pedro Garcia-Moreno, Rasmus K. Mikkelsen, and Simon Gregersen. "Physical and oxidative stability of emulsions stabilized with fractionated potato protein hydrolysates obtained from starch production byproduct: Use of bioinformatics and proteomics." In 2022 AOCS Annual Meeting & Expo. American Oil Chemists' Society (AOCS), 2022. http://dx.doi.org/10.21748/xxty9713.
Анотація:
With the increasing demand for sustainable and functional proteins from alternative sources, it is necessary to use advanced proteomics and bioinformatics tools for more time and cost-efficient research. The identification and release of abundant proteins/peptides from plant-based sources has been gaining significant attention by the food industry in the last decade. Despite its low protein content (1–2%), the magnitude of proteins obtained from the starch industry (~240,000 tons/year) makes potatoes a highly relevant source as a plant-based protein. Previously, we have identified and validated abundant peptides with good emulsifying and antioxidant properties using bioinformatics and proteomics tools as well as in vitro model systems. Using data-driven targeted hydrolysis, we were able to release validated, functional peptides from the potato protein obtained from potato fruit juice, a protein rich by-product of potato starch production. This work focuses on fractionation of potato protein hydrolysates (PPH) obtained through such targeted hydrolysis using trypsin and subsequent fraction characterization. Unfractionated (PPH1) and membrane-fractionated (PPH2 as >10kDa, PPH3 as 10-5kDa, PPH4 as 5-0.8kDa and PPH5 as < 0.8kDa) PPH was characterized for emulsifying and antioxidant properties/potential. Pendant drop technique and dilatational rheology were applied for determining interfacial tension and viscoelasticity of the PPH fractions at the oil-water interface. PPH2 (>10kDa) showed higher decrease of oil-water interfacial tension. All fractions predominantly provided elastic, weak and easily stretchable interfaces. PPH2 provided more rigid interfacial layer than the other fractions. Radical scavenging and metal chelating activities of PPHs were also tested and the best activities were provided by fractions >5kDa. Furthermore, their ability to form physically and oxidatively stable 5% fish oil-in-water emulsions were investigated during 8-day storage and results generally showed that fractions >5kDa provided the best stability followed by the 5–0.8kDa fraction.