scholarly journals Polydopamine coated CdSe@CdS dot-in-rod heterostructures with Rhodium-based catalysts for stable photocatalytic NAD+ reduction

2021 ◽  
Author(s):  
Marcel Boecker ◽  
Mathias Micheel ◽  
Alexander K. Mengele ◽  
Christof Neumann ◽  
Tilmann Herberger ◽  
...  
Keyword(s):  
Nicotinamide Adenine Dinucleotide ◽  
Reaction Centers ◽  
Covalent Attachment ◽  
Reduced Form ◽  
Spatial Proximity ◽  
Covalent Functionalization ◽  
Cds Nanorods ◽  
Photocatalytic System ◽  
Carrier Separation ◽  
Photocatalytic Applications

We report on a photocatalytic system consisting of CdSe@CdS nanorods, coated with a polydopamine (PDA) shell functionalized with molecular rhodium catalysts. The PDA shell was implemented to enhance photostability of the photosensitizer, to improve charge carrier separation and to offer multiple options for stable covalent functionalization, allowing for spatial proximity and efficient shuttling of charges between sensitizer and reaction center. The activity of the photocatalytic system was demonstrated by light-driven reduction of nicotinamide adenine dinucleotide (NAD+) to its reduced form NADH. This work shows that PDA coated nanostructures present an attractive platform for covalent attachment of reduction and oxidation reaction centers for photocatalytic applications.

scholarly journals Creating enzymes and self-sufficient cells for biosynthesis of the non-natural cofactor nicotinamide cytosine dinucleotide

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Xueying Wang ◽  
Yanbin Feng ◽  
Xiaojia Guo ◽  
Qian Wang ◽  
Siyang Ning ◽  
...  
Keyword(s):  
Biological Sciences ◽  
Escherichia Coli ◽  
Nicotinamide Adenine Dinucleotide ◽  
Chemical Biology ◽  
Reduced Form ◽  
Redox Transformations ◽  
Nicotinamide Mononucleotide ◽  
Self Sufficiency ◽  
Binding Pockets ◽  
Pathway Regulation

AbstractNicotinamide adenine dinucleotide (NAD) and its reduced form are indispensable cofactors in life. Diverse NAD mimics have been developed for applications in chemical and biological sciences. Nicotinamide cytosine dinucleotide (NCD) has emerged as a non-natural cofactor to mediate redox transformations, while cells are fed with chemically synthesized NCD. Here, we create NCD synthetase (NcdS) by reprograming the substrate binding pockets of nicotinic acid mononucleotide (NaMN) adenylyltransferase to favor cytidine triphosphate and nicotinamide mononucleotide over their regular substrates ATP and NaMN, respectively. Overexpression of NcdS alone in the model host Escherichia coli facilitated intracellular production of NCD, and higher NCD levels up to 5.0 mM were achieved upon further pathway regulation. Finally, the non-natural cofactor self-sufficiency was confirmed by mediating an NCD-linked metabolic circuit to convert L-malate into D-lactate. NcdS together with NCD-linked enzymes offer unique tools and opportunities for intriguing studies in chemical biology and synthetic biology.

scholarly journals Cesium Treatment Depresses Glycolysis Pathway in HeLa Cell

2021 ◽  
Vol 55 (4) ◽  
pp. 477-488
Keyword(s):  
Hela Cell ◽  
Nicotinamide Adenine Dinucleotide ◽  
Aerobic Glycolysis ◽  
Biological Effects ◽  
Glycolytic Enzyme ◽  
Nicotinamide Adenine ◽  
Reduced Form ◽  
Dependent Manner ◽  
Nadh Ratio ◽  
Glycolysis Pathway

Background/Aims: Cesium (Cs) is an alkali metal element that is of no essential use for humans; it has no known beneficial function that is verified by clinical research. When used as an alternative cancer therapy, it even causes toxicity in high doses. Thus, before using Cs as treatment in clinical settings, it is important to clearly determine its biological effects on cells. However, Cs was found to suppress the proliferation of human cervical cancer cells in a dose-dependent manner, and it was assumed that Cs inhibits the glycolysis pathway. In this study, we clearly determined the step of the glycolysis pathway that is affected by Cs. Methods: The glycolytic enzyme expressions, activities, and metabolite concentrations in HeLa cells were measured by PCR, western blotting, and enzymatic methods, after treating the cells with Cs for 3 days. Results: Cs treatment decreased transcriptional and expression levels of hexokinase, glyceraldehyde-3-phosphate dehydrogenase, pyruvate kinase (PK), and lactate dehydrogenase and the activity of PK. Analysis of glycolysis pathway metabolites revealed that Cs treatment reduces lactate level and increases the level of nicotinamide adenine dinucleotide (oxidized form, NAD+); however, it did not affect the levels of pyruvate and nicotinamide adenine dinucleotide (reduced form, NADH). Increase of the [NAD+]/[NADH] ratio and decrease of the [lactate]/[pyruvate] ratio indicate that Cs treatment inhibits the aerobic glycolysis pathway. Conclusion: Cs treatment inhibits PK activity and increases the [NAD+]/[NADH] ratio. Hence, Cs has been determined to inhibit glycolysis, especially the aerobic glycolysis pathway. These results suggest that suppression of HeLa cell proliferation following Cs treatment was caused by inhibition of aerobic glycolysis by Cs.

scholarly journals Monitoring the skin NADH changes during ischaemia and reperfusion in humans

2020 ◽  
Vol 89 (1) ◽  
pp. e405
Author(s):  
Jan Nizinski ◽  
Lukasz Kamieniarz ◽  
Piotr Filberek ◽  
Greta Sibrecht ◽  
Przemysław Guzik
Keyword(s):  
Optical Properties ◽  
Nicotinamide Adenine Dinucleotide ◽  
Energy Production ◽  
Reduced Form ◽  
Human Metabolism ◽  
Dynamic Changes ◽  
Non Invasive ◽  
Ischaemia And Reperfusion ◽  
Invasive Method ◽  
Skin Fluorescence

Nicotinamide adenine dinucleotide (NADH/NAD+) is involved in many important biochemical reactions in human metabolism, including participation in energy production by mitochondria. Flow Mediated Skin Fluorescence (FMSF) is a non-invasive method to study dynamic changes in the content of the reduced form of NADH by measuring the optical properties of NADH related to the emission of the autofluorescent light (460 nm) after an earlier excitation by ultraviolet light. This review summarises the available studies using this method to describe its potential and limitations.

scholarly journals Activation of 3-Mercaptopyruvate Sulfurtransferase by Glutaredoxin Reducing System

Biomolecules ◽  
2020 ◽  
Vol 10 (6) ◽  
pp. 826
Author(s):  
Noriyuki Nagahara
Keyword(s):  
Oxidative Stress ◽  
Electron Transfer ◽  
Glutathione Reductase ◽  
Nicotinamide Adenine Dinucleotide ◽  
Transfer Reaction ◽  
Nicotinamide Adenine Dinucleotide Phosphate ◽  
Electron Transfer Reaction ◽  
Reduced Form ◽  
Mercaptopyruvate Sulfurtransferase ◽  
Substrate Proteins

Glutaredoxin (EC 1.15–1.21) is known as an oxidoreductase that protects cysteine residues within proteins against oxidative stress. Glutaredoxin catalyzes an electron transfer reaction that donates an electron to substrate proteins in the reducing system composed of glutaredoxin, glutathione, glutathione reductase, and nicotinamide-adenine dinucleotide phosphate (reduced form). 3-mercaptopyruvate sulfurtransferase (EC 2.8.1.2) is a cysteine enzyme that catalyzes transsulfuration, and glutaredoxin activates 3-mercaptopyruvate sulfurtransferase in the reducing system. Interestingly, even when glutathione or glutathione reductase was absent, 3-mercaptopyruvate sulfurtransferase activity increased, probably because reduced glutaredoxin was partly present and able to activate 3-mercaptopyruvate sulfurtransferase until depletion. A study using mutant Escherichia coli glutaredoxin1 (Cys14 is the binding site of glutathione and was replaced with a Ser residue) confirmed these results. Some inconsistency was noted, and glutaredoxin with higher redox potential than either 3-mercaptopyruvate sulfurtransferase or glutathione reduced 3-mercaptopyruvate sulfurtransferase. However, electron-transfer enzymatically proceeded from glutaredoxin to 3-mercaptopyruvate sulfurtransferase.

Recent Advances in the Fabrication of All-Solid-State Nanostructured TiO2-Based Z-scheme Heterojunctions for Environmental Remediation

2020 ◽  
Vol 20 (9) ◽  
pp. 5861-5873 ◽  
Author(s):  
Meiqi Du ◽  
Shengxin Cao ◽  
Xiaozhou Ye ◽  
Jianfeng Ye
Keyword(s):  
Solid State ◽  
Charge Carrier ◽  
Environmental Remediation ◽  
Rational Design ◽  
High Efficiency ◽  
Photogenerated Charge Carrier ◽  
Advantages And Disadvantages ◽  
Recent Advances ◽  
Photocatalytic System ◽  
Carrier Separation

Nanostructured TiO2-based Z-scheme heterojunctions have been widely accepted to be among the most effective photocatalysts for environmental remediation owing to their broadened light absorbance, high efficiency of photogenerated charge carrier separation, and well-preserved strong oxidation and reduction capability. In this review, we will first introduce the photogenerated charge carrier transportation mechanism of three different types of Z-scheme heterojunction systems, namely, liquid-phase Z-scheme photocatalytic system, all-solid-state indirect Z-scheme photocatalytic system, and all-solid-state direct Z-scheme photocatalytic system. Subsequently, we will describe the recent advances toward the rational design and fabrication of all-solid-state nanostructured TiO2-based Z-scheme heterojunctions. The applications of the thus-constructed all-solid-state nanostructured TiO2-based Z-scheme heterojunctions in the degradation of volatile organic compounds, removal of waste water organic pollutants, and upgradation of greenhouse gas CO2 will then be presented one by one. Finally, the advantages and disadvantages of all-solid-state nanostructured TiO2-based Z-scheme heterojunction for photocatalytic environmental remediation will be briefly discussed, and the direction of future development will be prospected as well.

scholarly journals Insights into the TiO2-Based Photocatalytic Systems and Their Mechanisms

Catalysts ◽  
2019 ◽  
Vol 9 (8) ◽  
pp. 680 ◽  
Author(s):  
Sakar ◽  
Prakash ◽  
Do
Keyword(s):  
Band Structure ◽  
Co2 Reduction ◽  
H2 Production ◽  
Energy Structure ◽  
Energy Applications ◽  
Emerging Trends ◽  
Recent Developments ◽  
Carrier Separation ◽  
Photocatalytic Applications ◽  
Photocatalytic Materials

Photocatalysis is a multifunctional phenomenon that can be employed for energy applications such as H2 production, CO2 reduction into fuels, and environmental applications such as pollutant degradations, antibacterial disinfection, etc. In this direction, it is not an exaggerated fact that TiO2 is blooming in the field of photocatalysis, which is largely explored for various photocatalytic applications. The deeper understanding of TiO2 photocatalysis has led to the design of new photocatalytic materials with multiple functionalities. Accordingly, this paper exclusively reviews the recent developments in the modification of TiO2 photocatalyst towards the understanding of its photocatalytic mechanisms. These modifications generally involve the physical and chemical changes in TiO2 such as anisotropic structuring and integration with other metal oxides, plasmonic materials, carbon-based materials, etc. Such modifications essentially lead to the changes in the energy structure of TiO2 that largely boosts up the photocatalytic process via enhancing the band structure alignments, visible light absorption, carrier separation, and transportation in the system. For instance, the ability to align the band structure in TiO2 makes it suitable for multiple photocatalytic processes such as degradation of various pollutants, H2 production, CO2 conversion, etc. For these reasons, TiO2 can be realized as a prototypical photocatalyst, which paves ways to develop new photocatalytic materials in the field. In this context, this review paper sheds light into the emerging trends in TiO2 in terms of its modifications towards multifunctional photocatalytic applications.

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