Log in

Relevant bibliographies by topics / Motif ATCUN / Journal articles

To see the other types of publications on this topic, follow the link: Motif ATCUN.

Journal articles on the topic 'Motif ATCUN'

Author: Grafiati

Published: 8 February 2025

Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles

Select a source type:

Consult the top 41 journal articles for your research on the topic 'Motif ATCUN.'

Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.

You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.

Browse journal articles on a wide variety of disciplines and organise your bibliography correctly.

1

Chen, Ruei-Ching, and Chung-Yu Lan. "Human Antimicrobial Peptide Hepcidin 25-Induced Apoptosis in Candida albicans." Microorganisms 8, no. 4 (April 17, 2020): 585. http://dx.doi.org/10.3390/microorganisms8040585.

Full text

Abstract:

Hepcidin 25 (hep 25) is a cysteine-rich 25-amino acid antimicrobial peptide containing the amino-terminal Cu(II)/Ni(II)-binding (ATCUN) motif. Upon metal binding, the ATCUN motif is known to be involved in the generation of reactive oxygen species (ROS), especially hydrogen peroxide and hydroxyl radicals, which act against different bacterial species. However, the antifungal activity and its correlation to the Cu(II)-ATCUN complex of Hep 25 are still poorly understood. Here, we found that ROS accumulation plays an important role in the fungicidal activity of hep 25 against Candida albicans. In addition, Annexin V-FITC staining and TUNEL assay results provide clues about the apoptosis induced by hep 25. Moreover, hep 25 also increases the generation of ROS, possibly because of copper binding to the ATCUN motif, which is relevant to its activity against C. albicans. Finally, the C. albicans killing action of hep 25 is an energy- and temperature-dependent process that does not involve targeting the membrane. Taken together, our results provide new insights into the mechanisms of hep 25 against C. albicans cells and the potential use of hep 25 and its derivatives as novel antifungal agents.

APA, Harvard, Vancouver, ISO, and other styles

2

Miyamoto, Takaaki, Yuta Fukino, Shinichiro Kamino, Masashi Ueda, and Shuichi Enomoto. "Enhanced stability of Cu2+–ATCUN complexes under physiologically relevant conditions by insertion of structurally bulky and hydrophobic amino acid residues into the ATCUN motif." Dalton Transactions 45, no. 23 (2016): 9436–45. http://dx.doi.org/10.1039/c6dt01387b.

Full text

APA, Harvard, Vancouver, ISO, and other styles

3

Bacchella, Chiara, Simone Dell’Acqua, Stefania Nicolis, Enrico Monzani, and Luigi Casella. "Oxidase Reactivity of CuII Bound to N-Truncated Aβ Peptides Promoted by Dopamine." International Journal of Molecular Sciences 22, no. 10 (May 14, 2021): 5190. http://dx.doi.org/10.3390/ijms22105190.

Full text

Abstract:

The redox chemistry of copper(II) is strongly modulated by the coordination to amyloid-β peptides and by the stability of the resulting complexes. Amino-terminal copper and nickel binding motifs (ATCUN) identified in truncated Aβ sequences starting with Phe4 show very high affinity for copper(II) ions. Herein, we study the oxidase activity of [Cu–Aβ4−x] and [Cu–Aβ1−x] complexes toward dopamine and other catechols. The results show that the CuII–ATCUN site is not redox-inert; the reduction of the metal is induced by coordination of catechol to the metal and occurs through an inner sphere reaction. The generation of a ternary [CuII–Aβ–catechol] species determines the efficiency of the oxidation, although the reaction rate is ruled by reoxidation of the CuI complex. In addition to the N-terminal coordination site, the two vicinal histidines, His13 and His14, provide a second Cu-binding motif. Catechol oxidation studies together with structural insight from the mixed dinuclear complexes Ni/Cu–Aβ4−x reveal that the His-tandem is able to bind CuII ions independently of the ATCUN site, but the N-terminal metal complexation reduces the conformational mobility of the peptide chain, preventing the binding and oxidative reactivity toward catechol of CuII bound to the secondary site.

APA, Harvard, Vancouver, ISO, and other styles

4

Magrì, Antonio, Giovanni Tabbì, Irina Naletova, Francesco Attanasio, Giuseppe Arena, and Enrico Rizzarelli. "A Deeper Insight in Metal Binding to the hCtr1 N-terminus Fragment: Affinity, Speciation and Binding Mode of Binuclear Cu2+ and Mononuclear Ag+ Complex Species." International Journal of Molecular Sciences 23, no. 6 (March 8, 2022): 2929. http://dx.doi.org/10.3390/ijms23062929.

Full text

Abstract:

Ctr1 regulates copper uptake and its intracellular distribution. The first 14 amino acid sequence of the Ctr1 ectodomain Ctr1(1-14) encompasses the characteristic Amino Terminal Cu2+ and Ni2+ binding motif (ATCUN) as well as the bis-His binding motif (His5 and His6). We report a combined thermodynamic and spectroscopic (UV-vis, CD, EPR) study dealing with the formation of Cu2+ homobinuclear complexes with Ctr1(1-14), the percentage of which is not negligible even in the presence of a small Cu2+ excess and clearly prevails at a M/L ratio of 1.9. Ascorbate fails to reduce Cu2+ when bound to the ATCUN motif, while it reduces Cu2+ when bound to the His5-His6 motif involved in the formation of binuclear species. The histidine diade characterizes the second binding site and is thought to be responsible for ascorbate oxidation. Binding constants and speciation of Ag+ complexes with Ctr1(1-14), which are assumed to mimic Cu+ interaction with N-terminus of Ctr1(1-14), were also determined. A preliminary immunoblot assay evidences that the anti-Ctr1 extracellular antibody recognizes Ctr1(1-14) in a different way from the longer Ctr1(1-25) that encompasses a second His and Met rich domain.

APA, Harvard, Vancouver, ISO, and other styles

5

Neupane, Kosh P., Amanda R. Aldous, and Joshua A. Kritzer. "Macrocyclization of the ATCUN Motif Controls Metal Binding and Catalysis." Inorganic Chemistry 52, no. 5 (February 19, 2013): 2729–35. http://dx.doi.org/10.1021/ic302820z.

Full text

APA, Harvard, Vancouver, ISO, and other styles

6

Greve, Jenna M., and J. A. Cowan. "Activity and Synergy of Cu-ATCUN Antimicrobial Peptides." International Journal of Molecular Sciences 23, no. 22 (November 16, 2022): 14151. http://dx.doi.org/10.3390/ijms232214151.

Full text

Abstract:

Antibiotic resistance demands innovative strategies and therapies. The pairs of antimicrobial peptides tested in this work show broad-spectrum synergy and are capable of interacting with diverse bacterial membranes. In most cases, the ATCUN motif enhanced the activity of peptides tested in combination. Our studies also show CP10A to be a multifaceted peptide, displaying both cell membrane and intracellular activity and acting as a chameleon, improving the activity of other peptides as needed. The results of the synergy experiments demonstrate the importance of varied modes of action and how these changes can affect the ability to combat pathogens, while also illustrating the value of the metal-binding domain in enhancing the activity of antimicrobial peptides in combination.

APA, Harvard, Vancouver, ISO, and other styles

7

Santoro, Alice, Gulshan Walke, Bertrand Vileno, Prasad P. Kulkarni, Laurent Raibaut, and Peter Faller. "Low catalytic activity of the Cu(ii)-binding motif (Xxx-Zzz-His; ATCUN) in reactive oxygen species production and inhibition by the Cu(i)-chelator BCS." Chemical Communications 54, no. 84 (2018): 11945–48. http://dx.doi.org/10.1039/c8cc06040a.

Full text

APA, Harvard, Vancouver, ISO, and other styles

8

Mital, Mariusz, Kosma Szutkowski, Karolina Bossak-Ahmad, Piotr Skrobecki, Simon C. Drew, Jarosław Poznański, Igor Zhukov, Tomasz Frączyk, and Wojciech Bal. "The Palladium(II) Complex of Aβ4−16 as Suitable Model for Structural Studies of Biorelevant Copper(II) Complexes of N-Truncated Beta-Amyloids." International Journal of Molecular Sciences 21, no. 23 (December 2, 2020): 9200. http://dx.doi.org/10.3390/ijms21239200.

Full text

Abstract:

The Aβ4−42 peptide is a major beta-amyloid species in the human brain, forming toxic aggregates related to Alzheimer’s Disease. It also strongly chelates Cu(II) at the N-terminal Phe-Arg-His ATCUN motif, as demonstrated in Aβ4−16 and Aβ4−9 model peptides. The resulting complex resists ROS generation and exchange processes and may help protect synapses from copper-related oxidative damage. Structural characterization of Cu(II)Aβ4−x complexes by NMR would help elucidate their biological function, but is precluded by Cu(II) paramagneticism. Instead we used an isostructural diamagnetic Pd(II)-Aβ4−16 complex as a model. To avoid a kinetic trapping of Pd(II) in an inappropriate transient structure, we designed an appropriate pH-dependent synthetic procedure for ATCUN Pd(II)Aβ4−16, controlled by CD, fluorescence and ESI-MS. Its assignments and structure at pH 6.5 were obtained by TOCSY, NOESY, ROESY, 1H-13C HSQC and 1H-15N HSQC NMR experiments, for natural abundance 13C and 15N isotopes, aided by corresponding experiments for Pd(II)-Phe-Arg-His. The square-planar Pd(II)-ATCUN coordination was confirmed, with the rest of the peptide mostly unstructured. The diffusion rates of Aβ4−16, Pd(II)-Aβ4−16 and their mixture determined using PGSE-NMR experiment suggested that the Pd(II) complex forms a supramolecular assembly with the apopeptide. These results confirm that Pd(II) substitution enables NMR studies of structural aspects of Cu(II)-Aβ complexes.

APA, Harvard, Vancouver, ISO, and other styles

9

Domergue, Jérémy, Pawel Guinard, Magali Douillard, Jacques Pécaut, Olivier Proux, Colette Lebrun, Alan Le Goff, Pascale Maldivi, Pascale Delangle, and Carole Duboc. "A Bioinspired NiII Superoxide Dismutase Catalyst Designed on an ATCUN-like Binding Motif." Inorganic Chemistry 60, no. 17 (August 20, 2021): 12772–80. http://dx.doi.org/10.1021/acs.inorgchem.1c00899.

Full text

APA, Harvard, Vancouver, ISO, and other styles

10

Ginotra, Yamini P., Shefali N. Ramteke, Rapole Srikanth, and Prasad P. Kulkarni. "Mass Spectral Studies Reveal the Structure of Aβ1–16–Cu2+Complex Resembling ATCUN Motif." Inorganic Chemistry 51, no. 15 (July 17, 2012): 7960–62. http://dx.doi.org/10.1021/ic301244x.

Full text

APA, Harvard, Vancouver, ISO, and other styles

11

Donaldson, Logan W., Nikolai R. Skrynnikov, Wing-Yiu Choy, D. Ranjith Muhandiram, Bibudhendra Sarkar, Julie D. Forman-Kay, and Lewis E. Kay. "Structural Characterization of Proteins with an Attached ATCUN Motif by Paramagnetic Relaxation Enhancement NMR Spectroscopy." Journal of the American Chemical Society 123, no. 40 (October 2001): 9843–47. http://dx.doi.org/10.1021/ja011241p.

Full text

APA, Harvard, Vancouver, ISO, and other styles

12

González-Díaz, Humberto, Ángeles Sánchez-González, and Yenny González-Díaz. "3D-QSAR study for DNA cleavage proteins with a potential anti-tumor ATCUN-like motif." Journal of Inorganic Biochemistry 100, no. 7 (July 2006): 1290–97. http://dx.doi.org/10.1016/j.jinorgbio.2006.02.019.

Full text

APA, Harvard, Vancouver, ISO, and other styles

13

Gasmi, Geneviève, ALEX SINGER, JULIE FORMAN-KAY, and BIBUDHENDRA SARKAR. "NMR structure of neuromedin C, a neurotransmitter with an amino terminal CuII-, NiII-binding (ATCUN) motif." Journal of Peptide Research 49, no. 6 (January 12, 2009): 500–509. http://dx.doi.org/10.1111/j.1399-3011.1997.tb01157.x.

Full text

APA, Harvard, Vancouver, ISO, and other styles

14

Munteanu, Cristian R., José M. Vázquez, Julián Dorado, Alejandro Pazos Sierra, Ángeles Sánchez-González, Francisco J. Prado-Prado, and Humberto González-Díaz. "Complex Network Spectral Moments for ATCUN Motif DNA Cleavage: First Predictive Study on Proteins of Human Pathogen Parasites." Journal of Proteome Research 8, no. 11 (November 6, 2009): 5219–28. http://dx.doi.org/10.1021/pr900556g.

Full text

APA, Harvard, Vancouver, ISO, and other styles

15

Witkowska, Danuta, Agnieszka Szebesczyk, Joanna Wątły, Michał Braczkowski, and Magdalena Rowińska-Żyrek. "A Comparative Study on Nickel Binding to Hpn-like Polypeptides from Two Helicobacter pylori Strains." International Journal of Molecular Sciences 22, no. 24 (December 8, 2021): 13210. http://dx.doi.org/10.3390/ijms222413210.

Full text

Abstract:

Combined potentiometric titration and isothermal titration calorimetry (ITC) methods were used to study the interactions of nickel(II) ions with the N-terminal fragments and histidine-rich fragments of Hpn-like protein from two Helicobacter pylori strains (11637 and 26695). The ITC measurements were performed at various temperatures and buffers in order to extract proton-independent reaction enthalpies of nickel binding to each of the studied protein fragments. We bring up the problem of ITC results of nickel binding to the Hpn-like protein being not always compatible with those from potentiometry and MS regarding the stoichiometry and affinity. The roles of the ATCUN motif and multiple His and Gln residues in Ni(II) binding are discussed. The results provided the possibility to compare the Ni(II) binding properties between N-terminal and histidine-rich part of Hpn-like protein and between N-terminal parts of two Hpn-like strains, which differ mainly in the number of glutamine residues.

APA, Harvard, Vancouver, ISO, and other styles

16

Harford, C., and B. Sarkar. "Neuromedin C Binds Cu(II) and Ni(II) via the ATCUN Motif: Implications for the CNS and Cancer Growth." Biochemical and Biophysical Research Communications 209, no. 3 (April 1995): 877–82. http://dx.doi.org/10.1006/bbrc.1995.1580.

Full text

APA, Harvard, Vancouver, ISO, and other styles

17

Harford, Catherine, and Bibudhendra Sarkar. "Amino Terminal Cu(II)- and Ni(II)-Binding (ATCUN) Motif of Proteins and Peptides: Metal Binding, DNA Cleavage, and Other Properties†." Accounts of Chemical Research 30, no. 3 (March 1997): 123–30. http://dx.doi.org/10.1021/ar9501535.

Full text

APA, Harvard, Vancouver, ISO, and other styles

18

Plaza-Garrido, Marina, Mª Carmen Salinas-García, José C. Martínez, and Ana Cámara-Artigas. "The effect of an engineered ATCUN motif on the structure and biophysical properties of the SH3 domain of c-Src tyrosine kinase." JBIC Journal of Biological Inorganic Chemistry 25, no. 4 (April 11, 2020): 621–34. http://dx.doi.org/10.1007/s00775-020-01785-0.

Full text

APA, Harvard, Vancouver, ISO, and other styles

19

Shin, Min Kyoung, Hye-Ran Park, In-Wook Hwang, Kyung-Bin Bu, Bo-Young Jang, Seung-Ho Lee, Jin Wook Oh, Jung Sun Yoo, and Jung-Suk Sung. "In Silico-Based Design of a Hybrid Peptide with Antimicrobial Activity against Multidrug-Resistant Pseudomonas aeruginosa Using a Spider Toxin Peptide." Toxins 15, no. 12 (November 23, 2023): 668. http://dx.doi.org/10.3390/toxins15120668.

Full text

Abstract:

The escalating prevalence of antibiotic-resistant bacteria poses an immediate and grave threat to public health. Antimicrobial peptides (AMPs) have gained significant attention as a promising alternative to conventional antibiotics. Animal venom comprises a diverse array of bioactive compounds, which can be a rich source for identifying new functional peptides. In this study, we identified a toxin peptide, Lycotoxin-Pa1a (Lytx-Pa1a), from the transcriptome of the Pardosa astrigera spider venom gland. To enhance its functional properties, we employed an in silico approach to design a novel hybrid peptide, KFH-Pa1a, by predicting antibacterial and cytotoxic functionalities and incorporating the amino-terminal Cu(II)- and Ni(II) (ATCUN)-binding motif. KFH-Pa1a demonstrated markedly superior antimicrobial efficacy against pathogens, including multidrug-resistant (MDR) Pseudomonas aeruginosa, compared to Lytx-Pa1a. Notably, KFH-Pa1a exerted several distinct mechanisms, including the disruption of the bacterial cytoplasmic membrane, the generation of intracellular ROS, and the cleavage and inhibition of bacterial DNA. Additionally, the hybrid peptide showed synergistic activity when combined with conventional antibiotics. Our research not only identified a novel toxin peptide from spider venom but demonstrated in silico-based design of hybrid AMP with strong antimicrobial activity that can contribute to combating MDR pathogens, broadening the utilization of biological resources by incorporating computational approaches.

APA, Harvard, Vancouver, ISO, and other styles

20

HARFORD, C., and B. SARKAR. "ChemInform Abstract: Amino Terminal Cu(II)- and Ni(II)-Binding (ATCUN) Motif of Proteins and Peptides: Metal Binding, DNA Cleavage, and Other Properties." ChemInform 28, no. 27 (August 3, 2010): no. http://dx.doi.org/10.1002/chin.199727316.

Full text

APA, Harvard, Vancouver, ISO, and other styles

21

Abbas, Ioana M., Marija Vranic, Holger Hoffmann, Ahmed H. El-Khatib, María Montes-Bayón, Heiko M. Möller, and Michael G. Weller. "Investigations of the Copper Peptide Hepcidin-25 by LC-MS/MS and NMR." International Journal of Molecular Sciences 19, no. 8 (August 2, 2018): 2271. http://dx.doi.org/10.3390/ijms19082271.

Full text

Abstract:

Hepcidin-25 was identified as the main iron regulator in the human body, and it by binds to the sole iron-exporter ferroportin. Studies showed that the N-terminus of hepcidin is responsible for this interaction, the same N-terminus that encompasses a small copper(II)-binding site known as the ATCUN (amino-terminal Cu(II)- and Ni(II)-binding) motif. Interestingly, this copper-binding property is largely ignored in most papers dealing with hepcidin-25. In this context, detailed investigations of the complex formed between hepcidin-25 and copper could reveal insight into its biological role. The present work focuses on metal-bound hepcidin-25 that can be considered the biologically active form. The first part is devoted to the reversed-phase chromatographic separation of copper-bound and copper-free hepcidin-25 achieved by applying basic mobile phases containing 0.1% ammonia. Further, mass spectrometry (tandem mass spectrometry (MS/MS), high-resolution mass spectrometry (HRMS)) and nuclear magnetic resonance (NMR) spectroscopy were employed to characterize the copper-peptide. Lastly, a three-dimensional (3D) model of hepcidin-25 with bound copper(II) is presented. The identification of metal complexes and potential isoforms and isomers, from which the latter usually are left undetected by mass spectrometry, led to the conclusion that complementary analytical methods are needed to characterize a peptide calibrant or reference material comprehensively. Quantitative nuclear magnetic resonance (qNMR), inductively-coupled plasma mass spectrometry (ICP-MS), ion-mobility spectrometry (IMS) and chiral amino acid analysis (AAA) should be considered among others.

APA, Harvard, Vancouver, ISO, and other styles

22

Lefèvre, Margot, Kyangwi P. Malikidogo, Charlène Esmieu, and Christelle Hureau. "Sequence–Activity Relationship of ATCUN Peptides in the Context of Alzheimer’s Disease." Molecules 27, no. 22 (November 15, 2022): 7903. http://dx.doi.org/10.3390/molecules27227903.

Full text

Abstract:

Amino-terminal CuII and NiII (ATCUN) binding sequences are widespread in the biological world. Here, we report on the study of eight ATCUN peptides aimed at targeting copper ions and stopping the associated formation of reactive oxygen species (ROS). This study was actually more focused on Cu(Aβ)-induced ROS production in which the Aβ peptide is the “villain” linked to Alzheimer’s disease. The full characterization of CuII binding to the ATCUN peptides, the CuII extraction from CuII(Aβ), and the ability of the peptides to prevent and/or stop ROS formation are described in the relevant biological conditions. We highlighted in this research that all the ATCUN motifs studied formed the same thermodynamic complex but that the addition of a second histidine in position 1 or 2 allowed for an improvement in the CuII uptake kinetics. This kinetic rate was directly related to the ability of the peptide to stop the CuII(Aβ)-induced production of ROS, with the most efficient motifs being HWHG and HGHW.

APA, Harvard, Vancouver, ISO, and other styles

23

Frączyk, Tomasz. "Phosphorylation Impacts Cu(II) Binding by ATCUN Motifs." Inorganic Chemistry 60, no. 12 (June 7, 2021): 8447–50. http://dx.doi.org/10.1021/acs.inorgchem.1c00939.

Full text

APA, Harvard, Vancouver, ISO, and other styles

24

Gonzalez, Paulina, Karolina Bossak-Ahmad, Bertrand Vileno, Nina E. Wezynfeld, Youssef El Khoury, Petra Hellwig, Christelle Hureau, Wojciech Bal, and Peter Faller. "Triggering Cu-coordination change in Cu(ii)-Ala-His-His by external ligands." Chemical Communications 55, no. 56 (2019): 8110–13. http://dx.doi.org/10.1039/c9cc03174j.

Full text

APA, Harvard, Vancouver, ISO, and other styles

25

Neupane, Kosh P., Amanda R. Aldous, and Joshua A. Kritzer. "Metal-binding and redox properties of substituted linear and cyclic ATCUN motifs." Journal of Inorganic Biochemistry 139 (October 2014): 65–76. http://dx.doi.org/10.1016/j.jinorgbio.2014.06.004.

Full text

APA, Harvard, Vancouver, ISO, and other styles

26

Gokhale, Nikhil H., and J. A. Cowan. "Inactivation of human angiotensin converting enzyme by copper peptide complexes containing ATCUN motifs." Chemical Communications, no. 47 (2005): 5916. http://dx.doi.org/10.1039/b511081e.

Full text

APA, Harvard, Vancouver, ISO, and other styles

27

Singh, Udai, Raj Singh, Nilesh Sharma, and Ramasre Prasad. "DNA Cleavage Study Using Copper (II)-GlyAibHis: A Tripeptide Complex Based on ATCUN Peptide Motifs." Protein & Peptide Letters 15, no. 1 (January 1, 2008): 13–19. http://dx.doi.org/10.2174/092986608783330378.

Full text

APA, Harvard, Vancouver, ISO, and other styles

28

Sankararamakrishnan, Ramasubbu, Sandeep Verma, and Sandeep Kumar. "ATCUN-like metal-binding motifs in proteins: Identification and characterization by crystal structure and sequence analysis." Proteins: Structure, Function, and Bioinformatics 58, no. 1 (October 26, 2004): 211–21. http://dx.doi.org/10.1002/prot.20265.

Full text

APA, Harvard, Vancouver, ISO, and other styles

29

Bouraguba, Merwan, Elise Glattard, Maxime Naudé, Rémi Pelletier, Christopher Aisenbrey, Burkhard Bechinger, Laurent Raibaut, Vincent Lebrun, and Peter Faller. "Copper-binding motifs Xxx-His or Xxx-Zzz-His (ATCUN) linked to an antimicrobial peptide: Cu-binding, antimicrobial activity and ROS production." Journal of Inorganic Biochemistry 213 (December 2020): 111255. http://dx.doi.org/10.1016/j.jinorgbio.2020.111255.

Full text

APA, Harvard, Vancouver, ISO, and other styles

30

Auliani, Antin, and Suripah Suripah. "Konsep fundamental matematika pada tenun songket siak." JPMI (Jurnal Pembelajaran Matematika Inovatif) 7, no. 5 (September 30, 2024): 849–62. http://dx.doi.org/10.22460/jpmi.v7i5.22010.

Full text

Abstract:

Along with the times, cultural values among the community, including students, are fading. An alternative that can be done is to preserve culture and reintroduce it through the formal education curriculum. So it is necessary to conduct this research with the aim of describing the fundamental mathematical concepts contained in Siak songket woven fabrics. This study uses a descriptive qualitative method. The respondents in this study are the owner of the Siak weaving industry, Mrs. Atun permai. The data collection techniques used in this study are observation, interviews and documentation. The data analysis technique is carried out through 4 stages, namely data collection, data reduction, data presentation and conclusion drawn. The results of this study show that the motif of Siak songket woven fabric comes from animals, plants, and celestial bodies and contains meanings, philosophies and mathematical ideas such as geometric transformations, units of time and social arithmetic concepts. Several mathematical concepts contained in Siak sticky woven fabric can be applied to contextual mathematics learning to make it easier to understand mathematical concepts and associate culture into mathematics learning.

APA, Harvard, Vancouver, ISO, and other styles

31

Heinrich, Julian, Elisa Siddiqui, Henrike Eckstein, Michael Naumann, and Nora Kulak. "Ascorbate: a forgotten component in the cytotoxicity of Cu(II) ATCUN peptide complexes." JBIC Journal of Biological Inorganic Chemistry, November 11, 2024. http://dx.doi.org/10.1007/s00775-024-02083-9.

Full text

Abstract:

AbstractIn 1983, Linus Pauling and colleagues reported about enhanced antitumor activity of the Cu(II) complex of the simplest ATCUN (amino terminal Cu(II) and Ni(II)-binding motif) peptide (NH2-Gly-Gly-His-COOH, GGH) in the presence of ascorbate as an additive. In the following 4 decades, structural modifications of this complex were implemented, however, anticancer activity could not be significantly increased. This has led to neglecting the ATCUN motif and its Cu(II) complexes as potential chemotherapeutic agents. Furthermore, the addition of ascorbate with its positive effect on the anticancer activity has fallen into oblivion. In this work, we compared Cu(II) GGH with Cu(II) ATCUN peptides bearing β-Ala instead of Gly at the 2nd position of the peptide sequence regarding their in vitro complex stability and cytotoxicity (MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) and annexin V-FITC (fluorescein isothiocyanate) apoptosis assay) towards three cancer cell lines (AGS, HeLa and NCI-N87). Such an exchange of amino acids led to an up to three-fold higher cytotoxic effect in the presence of ascorbate. We thus achieved a significant increase in the otherwise moderate cytotoxicity of Cu(II) ATCUN-like complexes. Lipophilicity assays (n-octanol/water coefficient, log P values) of the studied complexes were used to evaluate differences in the antiproliferative activity. Graphical abstract

APA, Harvard, Vancouver, ISO, and other styles

32

Dreab, Ana, and Craig A. Bayse. "The Effect of Metalation on Antimicrobial Piscidins Imbedded in Normal and Oxidized Lipid Bilayers." RSC Chemical Biology, 2023. http://dx.doi.org/10.1039/d3cb00035d.

Full text

Abstract:

Metalation of the N-terminal Amino Terminal Cu(II)- and Ni(II)-binding (ATCUN) motif may enhance the antimicrobial properties of piscidins. Molecular dynamics simulations of free and nickelated piscidins 1 and 3 (P1...

APA, Harvard, Vancouver, ISO, and other styles

33

Zhang, Wenhui, Xin Tian, and Xinming Li. "Fabrication of Nanocatalytic Medicine from Self‐Assembling Peptides Containing an ATCUN‐like Copper‐Binding Motif for Anticancer Therapy." ChemBioChem, May 27, 2024. http://dx.doi.org/10.1002/cbic.202400216.

Full text

Abstract:

Development of nanomaterials with multiple enzymatic activities via a facile approach receives growing interests in recent years. Although peptide self‐assembling provides an effective approach for the construction of biomimetic materials in recent years, fabrication of artificial enzymes from self‐assembling peptides with multiple catalytic activities for anticancer therapy is still a challenge. Here, we report a simple method to prepare nanocatalysts with multienzyme‐like activities from self‐assembling peptides containing ATCUN copper‐binding motifs. With the aid of the coordination interactions between the ATCUN motif and Cu(II) ions, these peptides could perform supramolecular self‐assembly to form nanomaterials with biomimetic peroxidase, ascorbate oxidase and glutathione peroxidase activities. Moreover, these trienzyme‐like effects can elevate oxidative stress levels and suppress the antioxidative capability of cancer cells, which synergistically induce the apoptosis of cancer cells. Because of the high biocompatibility, catalytic activities and drug encapsulation properties, this self‐assembled peptide provides a biomimetic platform for the development of new nanocatalytic medicines for multimodal synergistic cancer therapies.

APA, Harvard, Vancouver, ISO, and other styles

34

Nardella, Maria Incoronata, Mariagrazia Fortino, Alessandra Barbanente, Giovanni Natile, Adriana Pietropaolo, and Fabio Arnesano. "Multinuclear Metal-Binding Ability of the N-Terminal Region of Human Copper Transporter Ctr1: Dependence Upon pH and Metal Oxidation State." Frontiers in Molecular Biosciences 9 (May 5, 2022). http://dx.doi.org/10.3389/fmolb.2022.897621.

Full text

Abstract:

The 14mer peptide corresponding to the N-terminal region of human copper transporter Ctr1 was used to investigate the intricate mechanism of metal binding to this plasma membrane permease responsible for copper import in eukaryotic cells. The peptide contains a high-affinity ATCUN Cu(II)/Ni(II)-selective motif, a methionine-only MxMxxM Cu(I)/Ag(I)-selective motif and a double histidine HH(M) motif, which can bind both Cu(II) and Cu(I)/Ag(I) ions. Using a combination of NMR spectroscopy and electrospray mass spectrometry, clear evidence was gained that the Ctr1 peptide, at neutral pH, can bind one or two metal ions in the same or different oxidation states. Addition of ascorbate to a neutral solution containing Ctr11-14 and Cu(II) in 1:1 ratio does not cause an appreciable reduction of Cu(II) to Cu(I), which is indicative of a tight binding of Cu(II) to the ATCUN motif. However, by lowering the pH to 3.5, the Cu(II) ion detaches from the peptide and becomes susceptible to reduction to Cu(I) by ascorbate. It is noteworthy that at low pH, unlike Cu(II), Cu(I) stably binds to methionines of the peptide. This redox reaction could take place in the lumen of acidic organelles after Ctr1 internalization. Unlike Ctr11-14-Cu(II), bimetallic Ctr11-14-2Cu(II) is susceptible to partial reduction by ascorbate at neutral pH, which is indicative of a lower binding affinity of the second Cu(II) ion. The reduced copper remains bound to the peptide, most likely to the HH(M) motif. By lowering the pH to 3.5, Cu(I) shifts from HH(M) to methionine-only coordination, an indication that only the pH-insensitive methionine motif is competent for metal binding at low pH. The easy interconversion of monovalent cations between different coordination modes was supported by DFT calculations.

APA, Harvard, Vancouver, ISO, and other styles

35

Ekanayake, Ruwini S. K., Victor A. Streltsov, Stephen P. Best, and Christopher T. Chantler. "Nanostructure and dynamics of N-truncated copper amyloid-β peptides from advanced X-ray absorption fine structure." IUCrJ 11, no. 3 (April 11, 2024). http://dx.doi.org/10.1107/s2052252524001830.

Full text

Abstract:

An X-ray absorption spectroscopy (XAS) electrochemical cell was used to collect high-quality XAS measurements of N-truncated Cu:amyloid-β (Cu:Aβ) samples under near-physiological conditions. N-truncated Cu:Aβ peptide complexes contribute to oxidative stress and neurotoxicity in Alzheimer's patients' brains. However, the redox properties of copper in different Aβ peptide sequences are inconsistent. Therefore, the geometry of binding sites for the copper binding in Aβ4–8/12/16 was determined using novel advanced extended X-ray absorption fine structure (EXAFS) analysis. This enables these peptides to perform redox cycles in a manner that might produce toxicity in human brains. Fluorescence XAS measurements were corrected for systematic errors including defective-pixel data, monochromator glitches and dispersion of pixel spectra. Experimental uncertainties at each data point were measured explicitly from the point-wise variance of corrected pixel measurements. The copper-binding environments of Aβ4–8/12/16 were precisely determined by fitting XAS measurements with propagated experimental uncertainties, advanced analysis and hypothesis testing, providing a mechanism to pursue many similarly complex questions in bioscience. The low-temperature XAS measurements here determine that CuII is bound to the first amino acids in the high-affinity amino-terminal copper and nickel (ATCUN) binding motif with an oxygen in a tetragonal pyramid geometry in the Aβ4–8/12/16 peptides. Room-temperature XAS electrochemical-cell measurements observe metal reduction in the Aβ4–16 peptide. Robust investigations of XAS provide structural details of CuII binding with a very different bis-His motif and a water oxygen in a quasi-tetrahedral geometry. Oxidized XAS measurements of Aβ4–12/16 imply that both CuII and CuIII are accommodated in an ATCUN-like binding site. Hypotheses for these CuI, CuII and CuIII geometries were proven and disproven using the novel data and statistical analysis including F tests. Structural parameters were determined with an accuracy some tenfold better than literature claims of past work. A new protocol was also developed using EXAFS data analysis for monitoring radiation damage. This gives a template for advanced analysis of complex biosystems.

APA, Harvard, Vancouver, ISO, and other styles

36

Libardo, Mark Daben J., Vitaliy Y. Gorbatyuk, and Alfredo M. Angeles‐Boza. "The Peptide Ixosin Uses an ATCUN Motif for its Oxidative Antimicrobial Activity and its Synergy with Ixosin B." FASEB Journal 30, S1 (April 2016). http://dx.doi.org/10.1096/fasebj.30.1_supplement.1090.5.

Full text

APA, Harvard, Vancouver, ISO, and other styles

37

Libardo, Mark Daben Javate, Kushi Anand, Gopinath Krishnamoorthy, Stefan H. E. Kaufmann, Amit Singh, and Alfredo Angeles‐Boza. "Phagosomal Copper Triggers a Peptidomimetic's Oxidative Activity and Enables Eradication of Intracellular Mycobacterium tuberculosis." FASEB Journal 31, S1 (April 2017). http://dx.doi.org/10.1096/fasebj.31.1_supplement.939.11.

Full text

Abstract:

Copper, due to its inherent antimicrobial properties is enriched at sites of infection, particularly in mycobacteria‐containing phagosomes. However, recent studies show that M tuberculosis (Mtb) has multiple copper detoxification pathways allowing it to persist inside macrophages. A thorough in vitro investigation also showed that Mtb is highly susceptible to Ascorbic acid‐induced Reactive Oxygen Species (ROS). Using these information, we designed an all‐D‐amino acid antimicrobial peptide (DL‐10, DVIHRAGLQFPVGRVHRLLRK‐NH2) containing the Amino Terminal Copper and Nickel (ATCUN) Binding Unit Val‐Ile‐His. The ATCUN Motif binds strongly to cupric ions to form a metallopeptide that directly generates ROS under physiological conditions. We find that DL‐10 displays high activity against Mtb both in vitro and inside THP‐1 macrophages. This antimycobacterial activity was found to be linked to levels of free copper and molecular oxygen. Using a genetically encoded fluorescent sensor, we found that DL‐10 generates oxidative stress in M smegmatis (Msm), leading to efficient DNA cleavage. Incidentally, the oxidative burst coincides with the onset of Msm killing, further implicating ROS in its bactericidal action. DL‐10 is internalized by RAW264.7 macrophages via COP1‐mediated endocytosis. Using strategically positioned fluorophores along the DL‐10 primary structure, we were able to confirm DL‐10 copper binding inside macrophages, while, Isothermal Titration Calorimetry revealed a 500 nM Kd of binding. Moreover, by confocal microscopy, we found that DL‐10 effectively co‐localizes with intracellular Msm. This suggests that DL‐10 likely utilizes the endogenous phagosomal copper pool to kill intracellular mycobacteria. Finally, DL‐10 exhibits low cytotoxicity against RAW264.7 macrophages up to 128 uM. The high potency and the fact that DL‐10 circumvents proteolytic cleavage suggests that it is a good drug candidate. Our study also reveals an efficient way of sterilizing mycobacterial infections using host‐derived metal ions.

APA, Harvard, Vancouver, ISO, and other styles

38

Delangle, Pascale, Pawel Guinard, Sarah Hostachy, Léa Diebold, Jacques Pécaut, Alan Le Goff, and Carole Duboc. "Outstanding Superoxide Dismutase Catalytic Activity Of Simple Peptide‐Based Nickel(II) Complexes." Angewandte Chemie, July 16, 2024. http://dx.doi.org/10.1002/ange.202409343.

Full text

Abstract:

We present here the most active synthetic Ni superoxide dismutase (NiSOD) mimic reported to date. Reactive oxygen species are aggressive compounds, which concentrations are tightly regulated in vivo. Among them, the superoxide anion, O2⸱‐, is controlled by superoxide dismutases. Capitalizing on the versatility of the Amino‐Terminal CuII‐ and NiII‐binding (ATCUN) peptide motif, we introduced positive charges around the NiII center to favor the interaction with the superoxide radical anion. At physiological pH, the pentapeptide H‐Cys‐His‐Cys‐Arg‐Arg‐NH2 coordinates NiII after the deprotonation of one thiol, two amides, and either the second thiol or the N‐terminal ammonium, leading to an equilibrium between the two N3S1 and N2S2 coordination modes. Under catalytic conditions, a kcat value of 8.6(4) x 106 L.mol‐1.s‐1 was measured. Within the first second, the catalyst remained undegraded with quantitative consumption of O2⸱‐ (completed up to 37 catalytic cycles). An extra arginine (Arg) was introduced at the peptide C‐terminus to increase the global charge of the NiII complex from +1 to + 2. This had no effect on the catalytic performance, highlighting the critical role of charge distribution in space as a determining factor influencing the reactivity.

APA, Harvard, Vancouver, ISO, and other styles

39

Delangle, Pascale, Pawel Guinard, Sarah Hostachy, Léa Diebold, Jacques Pécaut, Alan Le Goff, and Carole Duboc. "Outstanding Superoxide Dismutase Catalytic Activity Of Simple Peptide‐Based Nickel(II) Complexes." Angewandte Chemie International Edition, July 16, 2024. http://dx.doi.org/10.1002/anie.202409343.

Full text

Abstract:

We present here the most active synthetic Ni superoxide dismutase (NiSOD) mimic reported to date. Reactive oxygen species are aggressive compounds, which concentrations are tightly regulated in vivo. Among them, the superoxide anion, O2⸱‐, is controlled by superoxide dismutases. Capitalizing on the versatility of the Amino‐Terminal CuII‐ and NiII‐binding (ATCUN) peptide motif, we introduced positive charges around the NiII center to favor the interaction with the superoxide radical anion. At physiological pH, the pentapeptide H‐Cys‐His‐Cys‐Arg‐Arg‐NH2 coordinates NiII after the deprotonation of one thiol, two amides, and either the second thiol or the N‐terminal ammonium, leading to an equilibrium between the two N3S1 and N2S2 coordination modes. Under catalytic conditions, a kcat value of 8.6(4) x 106 L.mol‐1.s‐1 was measured. Within the first second, the catalyst remained undegraded with quantitative consumption of O2⸱‐ (completed up to 37 catalytic cycles). An extra arginine (Arg) was introduced at the peptide C‐terminus to increase the global charge of the NiII complex from +1 to + 2. This had no effect on the catalytic performance, highlighting the critical role of charge distribution in space as a determining factor influencing the reactivity.

APA, Harvard, Vancouver, ISO, and other styles

40

Kotuniak, Radosław, and Wojciech Bal. "Reactive Cu2+-peptide intermediates revealed by kinetic studies gain relevance by matching time windows in copper metallomics." Metallomics, February 14, 2023. http://dx.doi.org/10.1093/mtomcs/mfad007.

Full text

Abstract:

Abstract The purpose of this essay is to propose that metallomic studies in the area of extracellular copper transport are incomplete without the explicit consideration of kinetics of Cu2+ion binding and exchange reactions. The kinetic data should be interpreted in the context of time constraints imposed by specific physiological processes. Examples from experimental studies of Cu2+ ion interactions with ATCUN/NTS (amino-terminal copper and nickel binding site/N-terminal site) motifs are used to demonstrate that duration and periodicity of such processes as bloodstream transport or neurotransmission promote the reaction intermediates to the role of physiological effectors. The unexpectedly long lifetimes of intermediate complexes lead to their accumulation and novel reactivities. The emerging ideas are discussed in the context of other research areas in metallomics.

APA, Harvard, Vancouver, ISO, and other styles

41

Libardo, M. Daben, Jorge L. Cervantes, Juan C. Salazar, and Alfredo M. Angeles-Boza. "Improved Bioactivity of Antimicrobial Peptides by Addition of Amino-Terminal Copper and Nickel (ATCUN) Binding Motifs." ChemMedChem, May 6, 2014, n/a. http://dx.doi.org/10.1002/cmdc.201402033.

Full text

APA, Harvard, Vancouver, ISO, and other styles

We offer discounts on all premium plans for authors whose works are included in thematic literature selections. Contact us to get a unique promo code!