scholarly journals Sensors Based on Metal Nanoclusters Stabilized on Designed Proteins

Biosensors ◽  
2018 ◽  
Vol 8 (4) ◽  
pp. 110 ◽  
Author(s):  
Antonio Aires ◽  
Elena Lopez-Martinez ◽  
Aitziber Cortajarena
Keyword(s):  
Reactive Oxygen Species ◽  
Optical Properties ◽  
Metal Ions ◽  
Temperature Sensors ◽  
Oxygen Species ◽  
Protein Scaffolds ◽  
Metal Nanoclusters ◽  
Designed Proteins ◽  
New Sensors ◽  
Potential Use

Among all new nanomaterials, metal nanoclusters (NCs) have attracted special attention due to their interesting optical properties, among others. Metal NCs have been recently studied and used as sensors for different analytes. However, there is a need to explore the potential of these new sensors in a systematic manner and to develop new systems to broaden the possibilities that sensing offers to the industry. In this work, we show the potential use of repeat protein scaffolds as versatile templates for the synthesis and stabilization of various metal NCs, specifically Au, Ag, and CuNCs. The resulting protein-metal NCs hybrids are evaluated as sensors for different stimuli such as temperature, ions, or reactive oxygen species (ROS). Among the three protein-metal NCs, all performed nicely as temperature sensors, AuNCs responded to metal ions, and AgNCs were able to detect ROS.

Amentoflavone: A Bifunctional Metal Chelator that Controls the Formation of Neurotoxic Soluble Aβ42 Oligomers

2020 ◽  
Author(s):  
Liang Sun ◽  
Anuj K. Sharma ◽  
Byung-Hee Han ◽  
Liviu M. Mirica
Keyword(s):  
Reactive Oxygen Species ◽  
Metal Ions ◽  
Antioxidant Properties ◽  
Reactive Oxygen ◽  
Amyloid Plaques ◽  
Transition Metal Ions ◽  
Oxygen Species ◽  
High Affinity ◽  
Amyloid Aβ ◽  
Β Amyloid

<p>Alzheimer's disease (AD) is the most common neurodegenerative disorder, yet the cause and progression of this disorder are not completely understood. While the main hallmark of AD is the deposition of amyloid plaques consisting of the β-amyloid (Aβ) peptide, transition metal ions are also known to play a significant role in disease pathology by expediting the formation of neurotoxic soluble β-amyloid (Aβ) oligomers, reactive oxygen species (ROS), and oxidative stress. Thus, bifunctional metal chelators that can control these deleterious properties are highly desirable. Herein, we show that amentoflavone (AMF) – a natural biflavonoid compound, exhibits good metal-chelating properties, especially for chelating Cu<sup>2+</sup> with very high affinity (pCu<sub>7.4</sub> = 10.44). In addition, AMF binds to Aβ fibrils with a high affinity (<i>K<sub>i</sub></i> = 287 ± 20 nM) – as revealed by a competition thioflavin T (ThT) assay, and specifically labels the amyloid plaques <i>ex vivo</i> in the brain sections of transgenic AD mice – as confirmed via immunostaining with an Ab antibody. The effect of AMF on Aβ<sub>42</sub> aggregation and disaggregation of Aβ<sub>42</sub> fibrils was also investigated, to reveal that AMF can control the formation of neurotoxic soluble Aβ<sub>42</sub> oligomers, both in absence and presence of metal ions, and as confirmed via cell toxicity studies. Furthermore, an ascorbate consumption assay shows that AMF exhibits potent antioxidant properties and can chelate Cu<sup>2+</sup> and significantly diminish the Cu<sup>2+</sup>-ascorbate redox cycling and reactive oxygen species (ROS) formation. Overall, these studies strongly suggest that AMF acts as a bifunctional chelator that can interact with various Aβ aggregates and reduce their neurotoxicity, can also bind Cu<sup>2+</sup> and mediate its deleterious redox properties, and thus AMF has the potential to be a lead compound for further therapeutic agent development for AD. </p>

Recent advances in semiconducting polymer dots as optical probes for biosensing

2021 ◽  
Author(s):  
Ye Yuan ◽  
Weiying Hou ◽  
Weiping Qin ◽  
Changfeng Wu
Keyword(s):  
Reactive Oxygen Species ◽  
Metal Ions ◽  
Reactive Oxygen ◽  
Oxygen Species ◽  
Optical Probes ◽  
Semiconducting Polymer ◽  
Ph Values ◽  
Recent Advances ◽  
Polymer Dots ◽  
Semiconducting Polymer Dots

This review mainly summarized the recent results that used bright polymer dots (Pdots) for the detection of different analytes such as reactive oxygen species (ROS), metal ions, pH values, and a variety of biomolecules.

scholarly journals Generation of Reactive Oxygen Species by Interaction between Antioxidants Used as Food Additive and Metal Ions

2014 ◽  
Vol 55 (4) ◽  
pp. 167-176 ◽  
Author(s):  
Yusuke IWASAKI ◽  
Momoko ODA ◽  
Yuri TSUKUDA ◽  
Yuki NAGAMORI ◽  
Hiroyuki NAKAZAWA ◽  
...  
Keyword(s):  
Reactive Oxygen Species ◽  
Metal Ions ◽  
Reactive Oxygen ◽  
Food Additive ◽  
Oxygen Species

Fluorescent and Colorimetric Chemosensors for Anions, Metal Ions, Reactive Oxygen Species, Biothiols, and Gases

2016 ◽  
Vol 37 (10) ◽  
pp. 1661-1678 ◽  
Author(s):  
Yifan Liu ◽  
Ying Hu ◽  
Songyi Lee ◽  
Dayoung Lee ◽  
Juyoung Yoon
Keyword(s):  
Reactive Oxygen Species ◽  
Metal Ions ◽  
Reactive Oxygen ◽  
Oxygen Species

Amentoflavone: A Bifunctional Metal Chelator that Controls the Formation of Neurotoxic Soluble Aβ42 Oligomers

2020 ◽  
Author(s):  
Liang Sun ◽  
Anuj K. Sharma ◽  
Byung-Hee Han ◽  
Liviu M. Mirica
Keyword(s):  
Reactive Oxygen Species ◽  
Metal Ions ◽  
Antioxidant Properties ◽  
Reactive Oxygen ◽  
Amyloid Plaques ◽  
Transition Metal Ions ◽  
Oxygen Species ◽  
High Affinity ◽  
Amyloid Aβ ◽  
Β Amyloid

<p>Alzheimer's disease (AD) is the most common neurodegenerative disorder, yet the cause and progression of this disorder are not completely understood. While the main hallmark of AD is the deposition of amyloid plaques consisting of the β-amyloid (Aβ) peptide, transition metal ions are also known to play a significant role in disease pathology by expediting the formation of neurotoxic soluble β-amyloid (Aβ) oligomers, reactive oxygen species (ROS), and oxidative stress. Thus, bifunctional metal chelators that can control these deleterious properties are highly desirable. Herein, we show that amentoflavone (AMF) – a natural biflavonoid compound, exhibits good metal-chelating properties, especially for chelating Cu<sup>2+</sup> with very high affinity (pCu<sub>7.4</sub> = 10.44). In addition, AMF binds to Aβ fibrils with a high affinity (<i>K<sub>i</sub></i> = 287 ± 20 nM) – as revealed by a competition thioflavin T (ThT) assay, and specifically labels the amyloid plaques <i>ex vivo</i> in the brain sections of transgenic AD mice – as confirmed via immunostaining with an Ab antibody. The effect of AMF on Aβ<sub>42</sub> aggregation and disaggregation of Aβ<sub>42</sub> fibrils was also investigated, to reveal that AMF can control the formation of neurotoxic soluble Aβ<sub>42</sub> oligomers, both in absence and presence of metal ions, and as confirmed via cell toxicity studies. Furthermore, an ascorbate consumption assay shows that AMF exhibits potent antioxidant properties and can chelate Cu<sup>2+</sup> and significantly diminish the Cu<sup>2+</sup>-ascorbate redox cycling and reactive oxygen species (ROS) formation. Overall, these studies strongly suggest that AMF acts as a bifunctional chelator that can interact with various Aβ aggregates and reduce their neurotoxicity, can also bind Cu<sup>2+</sup> and mediate its deleterious redox properties, and thus AMF has the potential to be a lead compound for further therapeutic agent development for AD. </p>

Effects of reactive oxygen species on the biological, structural, and optical properties of Cordyceps pruinosa spores

RSC Advances ◽  
2016 ◽  
Vol 6 (36) ◽  
pp. 30699-30709 ◽  
Author(s):  
Jun Young Kim ◽  
In Hee Lee ◽  
Daewook Kim ◽  
Seong Hwan Kim ◽  
Young-Wan Kwon ◽  
...  
Keyword(s):  
Reactive Oxygen Species ◽  
Cell Wall ◽  
Optical Properties ◽  
Dna Content ◽  
Reactive Oxygen ◽  
Structural Alteration ◽  
Oxygen Species ◽  
Antioxidative Capacity ◽  
Structural And Optical Properties ◽  
Spore Viability

Effects of reactive oxygen species on the biological and optical properties of Cordyceps pruinosa spores were studied. The decline in spore viability, antioxidative capacity, and DNA content were due to structural alteration of the cell wall.

scholarly journals Impaired Myocardial Bioenergetics in HFpEF and the Role of Antioxidants

2016 ◽  
Vol 10 (1) ◽  
pp. 158-162 ◽  
Author(s):  
John B. Hiebert ◽  
Qiuhua Shen ◽  
Amanda Thimmesch ◽  
Janet Pierce
Keyword(s):  
Heart Failure ◽  
Reactive Oxygen Species ◽  
Relevant Literature ◽  
Reactive Oxygen ◽  
Oxygen Species ◽  
Patients With Heart Failure ◽  
Free Radical Formation ◽  
Myocardial Bioenergetics ◽  
Potential Use

Heart failure with preserved ejection fraction (HFpEF) is a significant cardiovascular condition for more than 50% of patients with heart failure. Currently, there is no effective treatment to decrease morbidity and mortality rates associated with HFpEF because of its pathophysiological heterogeneity. Recent evidence shows that deficiency in myocardial bioenergetics is one of the key pathophysiological factors contributing to diastolic dysfunction in HFpEF. Another known mechanism for HFpEF is an overproduction of free radicals, specifically reactive oxygen species. To reduce free radical formation, antioxidants are often used. This article is a summative review of the recent relevant literature that addresses cardiac bioenergetics, deficiency in myocardial bioenergetics, and increased reactive oxygen species associated with HFpEF and the promising potential use of antioxidants in managing this condition.

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