Role of the C-Terminal Tyrosine of Ferredoxin-Nicotinamide Adenine Dinucleotide Phosphate Reductase in the Electron Transfer Processes with Its Protein Partners Ferredoxin and Flavodoxin†

Biochemistry ◽  
2004 ◽  
Vol 43 (20) ◽  
pp. 6127-6137 ◽  
Author(s):  
Isabel Nogués ◽  
Jesús Tejero ◽  
John K. Hurley ◽  
Darío Paladini ◽  
Susana Frago ◽  
...  
Keyword(s):  
Electron Transfer ◽  
Nicotinamide Adenine Dinucleotide ◽  
Nicotinamide Adenine Dinucleotide Phosphate ◽  
Nicotinamide Adenine ◽  
Transfer Processes ◽  
Protein Partners ◽  
Electron Transfer Processes

Effect of Niacin on Mitochondria of Allium Cepa Root Cells

1967 ◽  
Vol 25 ◽  
pp. 78-79
Author(s):  
M. Arif Hayat
Keyword(s):  
Nicotinamide Adenine Dinucleotide ◽  
Hydrogen Transfer ◽  
Nicotinamide Adenine Dinucleotide Phosphate ◽  
Nicotinamide Adenine ◽  
Root Tips ◽  
Root Cells ◽  
Transfer Processes ◽  
Standard Procedures ◽  
A Cell ◽  
Critical Interest

Although it is recognized that niacin (pyridine-3-carboxylic acid), incorporated as the amide in nicotinamide adenine dinucleotide (NAD) or in nicotinamide adenine dinucleotide phosphate (NADP), is a cofactor in hydrogen transfer in numerous enzyme reactions in all organisms studied, virtually no information is available on the effect of this vitamin on a cell at the submicroscopic level. Since mitochondria act as sites for many hydrogen transfer processes, the possible response of mitochondria to niacin treatment is, therefore, of critical interest.Onion bulbs were placed on vials filled with double distilled water in the dark at 25°C. After two days the bulbs and newly developed root system were transferred to vials containing 0.1% niacin. Root tips were collected at ¼, ½, 1, 2, 4, and 8 hr. intervals after treatment. The tissues were fixed in glutaraldehyde-OsO4 as well as in 2% KMnO4 according to standard procedures. In both cases, the tissues were dehydrated in an acetone series and embedded in Reynolds' lead citrate for 3-10 minutes.

scholarly journals Cellular and mitochondrial mechanisms of atrial fibrillation

2020 ◽  
Vol 115 (6) ◽  
Author(s):  
Fleur E. Mason ◽  
Julius Ryan D. Pronto ◽  
Khaled Alhussini ◽  
Christoph Maack ◽  
Niels Voigt
Keyword(s):  
Atrial Fibrillation ◽  
Nicotinamide Adenine Dinucleotide ◽  
Molecular Mechanisms ◽  
Treatment Options ◽  
Specific Treatment ◽  
Nicotinamide Adenine Dinucleotide Phosphate ◽  
Nicotinamide Adenine ◽  
Mitochondrial Activity ◽  
Atp Production

AbstractThe molecular mechanisms underlying atrial fibrillation (AF), the most common form of arrhythmia, are poorly understood and therefore target-specific treatment options remain an unmet clinical need. Excitation–contraction coupling in cardiac myocytes requires high amounts of adenosine triphosphate (ATP), which is replenished by oxidative phosphorylation in mitochondria. Calcium (Ca2+) is a key regulator of mitochondrial function by stimulating the Krebs cycle, which produces nicotinamide adenine dinucleotide for ATP production at the electron transport chain and nicotinamide adenine dinucleotide phosphate for the elimination of reactive oxygen species (ROS). While it is now well established that mitochondrial dysfunction plays an important role in the pathophysiology of heart failure, this has been less investigated in atrial myocytes in AF. Considering the high prevalence of AF, investigating the role of mitochondria in this disease may guide the path towards new therapeutic targets. In this review, we discuss the importance of mitochondrial Ca2+ handling in regulating ATP production and mitochondrial ROS emission and how alterations, particularly in these aspects of mitochondrial activity, may play a role in AF. In addition to describing research advances, we highlight areas in which further studies are required to elucidate the role of mitochondria in AF.

NAD(P)H oxidase–dependent platelet superoxide anion release increases platelet recruitment

Blood ◽  
2002 ◽  
Vol 100 (3) ◽  
pp. 917-924 ◽  
Author(s):  
Florian Krötz ◽  
Hae Young Sohn ◽  
Torsten Gloe ◽  
Stefan Zahler ◽  
Tobias Riexinger ◽  
...  
Keyword(s):  
Nicotinamide Adenine Dinucleotide ◽  
Thrombus Formation ◽  
Nicotinamide Adenine Dinucleotide Phosphate ◽  
Human Platelets ◽  
Nicotinamide Adenine ◽  
Irreversible Aggregation ◽  
Reduced Nicotinamide Adenine Dinucleotide ◽  
Specific Peptide

Abstract Platelets, although not phagocytotic, have been suggested to release O2−. Since O2−-producing reduced nicotinamide adenine dinucleotide (phosphate) (NAD(P)H) oxidases can be specifically activated by certain agonists and are found in several nonphagocytotic tissues, we investigated whether such an enzyme is the source of platelet-derived O2−. We further studied which agonists cause platelet O2−release and whether platelet-derived O2− influences thrombus formation in vitro. Collagen, but not adenosine 5′-diphosphate (ADP) or thrombin, increased O2− formation in washed human platelets. This was a reduced nicotinamide adenine dinucleotide (NADH)–dependent process, as shown in platelet lysates. Consistent with a role of a platelet, NAD(P)H oxidase expression of its subunits p47phox and p67phoxand inhibition of platelet O2− formation by diphenylene-iodoniumchloride (DPI) and by the specific peptide-antagonist gp91ds-tat were observed. Whereas platelet-derived O2− did not influence initial aggregation, platelet recruitment to a preformed thrombus following collagen stimulation was significantly attenuated by superoxide dismutase (SOD) or DPI. It was also inhibited when ADP released during aggregation was cleaved by the ectonucleotidase apyrase. ADP in supernatants of collagen-activated platelets was decreased in the presence of SOD, resulting in lower ADP concentrations available for recruitment of further platelets. Exogenous O2−increased ADP- concentrations in supernatants of collagen-stimulated platelets and induced irreversible aggregation when platelets were stimulated with otherwise subthreshold concentrations of ADP. These results strongly suggest that collagen activation induces NAD(P)H oxidase–dependent O2− release in platelets, which in turn enhances availability of released ADP, resulting in increased platelet recruitment.

On the theory of electron-transfer processes in aqueous solutions

1954 ◽  
Vol 222 (1148) ◽  
pp. 128-141 ◽  
Keyword(s):  
Electron Transfer ◽  
Point Of View ◽  
Complex Ions ◽  
Gaseous State ◽  
Biochemical Processes ◽  
Transfer Processes ◽  
Oxidation Reduction ◽  
Mechanical Interpretation ◽  
Electron Transfer Processes

It has been realized for some time that simple electron-transfer processes play an important part in the mechanism of many oxidation-reduction reactions in solution. An attempt has been made to give a quantum-mechanical interpretation of these processes on the basis of the earlier theories of electron transfer in the gaseous state (Landau 1932; Bates & Massey 1943). The present treatment for solutions takes into account the role of the solvent, with particular reference to the operation of the Franck—Condon principle and it also leads to some definite picture of the transition state for the electron transfer process. A number of examples are discussed, including electron transfer between like ions of different valency and also reactions involving complex ions, e.g. metal porphyrins, the reactions of which are of importance in certain biochemical processes. It appears that the application of certain theoretical principles leads to a satisfactory understanding of electron-transfer processes in solution from a qualitative and, in some cases, also from a semi-quantitative point of view.

scholarly journals Electron transfer processes in potassium collision with nitroimidazoles: the role of methylation at N1 site

2017 ◽  
Vol 875 ◽  
pp. 052035
Author(s):  
M. Mendes ◽  
F. Ferreira da Silva ◽  
G. García ◽  
P. Limão-Vieira
Keyword(s):  
Electron Transfer ◽  
Transfer Processes ◽  
Electron Transfer Processes

Unusual Role of Oxygen in Electron-Transfer Processes

2002 ◽  
Vol 124 (16) ◽  
pp. 4212-4213 ◽  
Author(s):  
Sergei Smirnov ◽  
Ivan Vlassiouk ◽  
Olaf Kutzki ◽  
Michael Wedel ◽  
Franz-Peter Montforts
Keyword(s):  
Electron Transfer ◽  
Transfer Processes ◽  
Electron Transfer Processes
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