Reactivation of electron flow in chloroplasts of in vitro shootlets of apple through elimination of carbon source and evaluation of its activity by inhibitors of electron transport chain and chlorophyll fluorescence quenching

2017 ◽  
Vol 131 (3) ◽  
pp. 377-389
Author(s):  
Hamid Abdollahi ◽  
Kobra Erfaninia ◽  
Zahra Ghahremani ◽  
Jaber Nasiri ◽  
Zeynab Salehi
Keyword(s):  
Chlorophyll Fluorescence ◽  
Electron Transport ◽  
Carbon Source ◽  
Fluorescence Quenching ◽  
Electron Transport Chain ◽  
Electron Flow ◽  
Chlorophyll Fluorescence Quenching ◽  
Transport Chain

scholarly journals Studies on the Mechanism by Which Anaerobiosis Prevents Swelling of Mitochondria in Vitro: Effect of Electron Transport Chain Inhibitors

1959 ◽  
Vol 234 (8) ◽  
pp. 2176-2186 ◽  
Author(s):  
F. Edmund Hunter ◽  
Jerome F. Levy ◽  
Joan Fink ◽  
Beverly Schutz ◽  
Francisco Guerra ◽  
...  
Keyword(s):  
Electron Transport ◽  
Electron Transport Chain ◽  
Transport Chain ◽  
Vitro Effect

Rewiring photosynthesis: a photosystem I-hydrogenase chimera that makes H2in vivo

2020 ◽  
Vol 13 (9) ◽  
pp. 2903-2914 ◽  
Author(s):  
Andrey Kanygin ◽  
Yuval Milrad ◽  
Chandrasekhar Thummala ◽  
Kiera Reifschneider ◽  
Patricia Baker ◽  
...  
Keyword(s):  
Electron Transport ◽  
Hydrogen Production ◽  
Photosystem I ◽  
Electron Transport Chain ◽  
Electron Flow ◽  
Photosynthetic Electron Transport ◽  
Photosynthetic Electron Transport Chain ◽  
Transport Chain

Photosystem I-hydrogenase chimera intercepts electron flow directly from the photosynthetic electron transport chain and directs it to hydrogen production.

scholarly journals Purification of Helicobacter pylori NCTC 11637 Cytochrome bc1 and Respiration with d-Proline as a Substrate

2009 ◽  
Vol 192 (5) ◽  
pp. 1410-1415 ◽  
Author(s):  
Minoru Tanigawa ◽  
Tomomitsu Shinohara ◽  
Katsushi Nishimura ◽  
Kumiko Nagata ◽  
Morio Ishizuka ◽  
...  
Keyword(s):  
Helicobacter Pylori ◽  
Amino Acid ◽  
Electron Transport ◽  
Electron Transport Chain ◽  
Electron Flow ◽  
Gene Clusters ◽  
Acid Dehydrogenase ◽  
Amino Acid Dehydrogenase ◽  
Transport Chain ◽  
H Pylori

ABSTRACT Helicobacter pylori is a microaerophilic bacterium associated with gastric inflammation and peptic ulcers. Knowledge of how pathogenic organisms produce energy is important from a therapeutic point of view. We found d-amino acid dehydrogenase-mediated electron transport from d-proline or d-alanine to oxygen via the respiratory chain in H. pylori. Coupling of the electron transport to ATP synthesis was confirmed by using uncoupler reagents. We reconstituted the electron transport chain to demonstrate the electron flow from the d-amino acids to oxygen using the recombinant cytochrome bc 1 complex, cytochrome c-553, and the terminal oxidase cytochrome cbb 3 complex. Upon addition of the recombinant d-amino acid dehydrogenase and d-proline or d-alanine to the reconstituted electron transport system, reduction of cytochrome cbb 3 and oxygen consumption was revealed spectrophotometrically and polarographically, respectively. Among the constituents of H. pylori's electron transport chain, only the cytochrome bc 1 complex had been remained unpurified. Therefore, we cloned and sequenced the H. pylori NCTC 11637 cytochrome bc 1 gene clusters encoding Rieske Fe-S protein, cytochrome b, and cytochrome c 1, with calculated molecular masses of 18 kDa, 47 kDa, and 32 kDa, respectively, and purified the recombinant monomeric protein complex with a molecular mass of 110 kDa by gel filtration. The absorption spectrum of the recombinant cytochrome bc 1 complex showed an α peak at 561 nm with a shoulder at 552 nm.

scholarly journals In vitro effect of globotriaosylceramide on electron transport chain complexes and redox parameters

2019 ◽  
Vol 91 (2) ◽  
Author(s):  
RAFAELA M. ALVARIZ ◽  
ISABEL T.D.S. MOREIRA ◽  
GABRIELA K. CURY ◽  
CARMEN R. VARGAS ◽  
ALETHÉA G. BARSCHAK
Keyword(s):  
Electron Transport ◽  
Electron Transport Chain ◽  
Chain Complexes ◽  
Transport Chain ◽  
Vitro Effect

scholarly journals H2S-stimulated bioenergetics in chicken erythrocytes and the underlying mechanism

2020 ◽  
Vol 319 (1) ◽  
pp. R69-R78
Author(s):  
Zhuping Jin ◽  
Quanxi Zhang ◽  
Eden Wondimu ◽  
Richa Verma ◽  
Ming Fu ◽  
...  
Keyword(s):  
Electron Transport ◽  
Mammalian Cells ◽  
Electron Transport Chain ◽  
Structural Integrity ◽  
Underlying Mechanism ◽  
Atp Content ◽  
Hypoxic Conditions ◽  
Transport Chain ◽  
Chicken Erythrocytes

The production of H2S and its effect on bioenergetics in mammalian cells may be evolutionarily preserved. Erythrocytes of birds, but not those of mammals, have a nucleus and mitochondria. In the present study, we report the endogenous production of H2S in chicken erythrocytes, which was mainly catalyzed by 3-mercaptopyruvate sulfur transferase (MST). ATP content of erythrocytes was increased by MST-generated endogenous H2S under normoxic, but not hypoxic, conditions. NaHS, a H2S salt, increased ATP content under normoxic, but not hypoxic, conditions. ATP contents in the absence or presence of NaHS were eliminated by different inhibitors for mitochondrial electron transport chain in chicken erythrocytes. Succinate and glutamine, but not glucose, increased ATP content. NaHS treatment similarly increased ATP content in the presence of glucose, glutamine, or succinate, respectively. Furthermore, the expression and activity of sulfide:quinone oxidoreductase were enhanced by NaHS. The structural integrity of chicken erythrocytes was largely maintained during 2-wk NaHS treatment in vitro, whereas most of the erythrocytes without NaHS treatment were lysed. In conclusion, H2S may regulate cellular bioenergetics as well as cell survival of chicken erythrocytes, in which the functionality of the electron transport chain is involved. H2S may have different regulatory roles and mechanisms in bioenergetics of mammalian and bird cells.

scholarly journals Tracking Electron Uptake from a Cathode into Shewanella Cells: Implications for Energy Acquisition from Solid-Substrate Electron Donors

mBio ◽  
2018 ◽  
Vol 9 (1) ◽  
Author(s):  
Annette R. Rowe ◽  
Pournami Rajeev ◽  
Abhiney Jain ◽  
Sahand Pirbadian ◽  
Akihiro Okamoto ◽  
...  
Keyword(s):  
Electron Transfer ◽  
Electron Transport ◽  
Complex I ◽  
Electron Transport Chain ◽  
Electron Flow ◽  
Extracellular Electron Transfer ◽  
Terminal Electron Acceptor ◽  
Cellular Energy ◽  
Transport Chain ◽  
Energy Acquisition

ABSTRACTWhile typically investigated as a microorganism capable of extracellular electron transfer to minerals or anodes,Shewanella oneidensisMR-1 can also facilitate electron flow from a cathode to terminal electron acceptors, such as fumarate or oxygen, thereby providing a model system for a process that has significant environmental and technological implications. This work demonstrates that cathodic electrons enter the electron transport chain ofS. oneidensiswhen oxygen is used as the terminal electron acceptor. The effect of electron transport chain inhibitors suggested that a proton gradient is generated during cathode oxidation, consistent with the higher cellular ATP levels measured in cathode-respiring cells than in controls. Cathode oxidation also correlated with an increase in the cellular redox (NADH/FMNH2) pool determined with a bioluminescence assay, a proton uncoupler, and a mutant of proton-pumping NADH oxidase complex I. This work suggested that the generation of NADH/FMNH2under cathodic conditions was linked to reverse electron flow mediated by complex I. A decrease in cathodic electron uptake was observed in various mutant strains, including those lacking the extracellular electron transfer components necessary for anodic-current generation. While no cell growth was observed under these conditions, here we show that cathode oxidation is linked to cellular energy acquisition, resulting in a quantifiable reduction in the cellular decay rate. This work highlights a potential mechanism for cell survival and/or persistence on cathodes, which might extend to environments where growth and division are severely limited.IMPORTANCEThe majority of our knowledge of the physiology of extracellular electron transfer derives from studies of electrons moving to the exterior of the cell. The physiological mechanisms and/or consequences of the reverse processes are largely uncharacterized. This report demonstrates that when coupled to oxygen reduction, electrode oxidation can result in cellular energy acquisition. This respiratory process has potentially important implications for how microorganisms persist in energy-limited environments, such as reduced sediments under changing redox conditions. From an applied perspective, this work has important implications for microbially catalyzed processes on electrodes, particularly with regard to understanding models of cellular conversion of electrons from cathodes to microbially synthesized products.

Analysis of the control of photosynthesis in C 4 plants by changes in light and carbon dioxide

1989 ◽  
Vol 323 (1216) ◽  
pp. 339-355 ◽  
Keyword(s):  
Chlorophyll Fluorescence ◽  
Fluorescence Quenching ◽  
Electron Flow ◽  
Calvin Cycle ◽  
Carbon Assimilation ◽  
Photon Flux ◽  
Low Light ◽  
Chlorophyll Fluorescence Quenching ◽  
Photosynthetic Carbon ◽  
Photosynthetic Carbon Assimilation

Parallel measurements of contents of photosynthetic intermediates, activities of enzymes of photosynthetic carbon assimilation, gas-exchange rates and components of chlorophyll-fluorescence quenching in leaves of C 4 plants are considered in relation to changes in photon flux density (PFD) and CO 2 . The influence of varying light and CO 2 concentration upon changes in the amounts of phosphoenolpyruvate (PEP) in leaves of C 4 plants during steady-state photosynthesis are interpreted in terms of the regulatory properties of PEP carboxylase and in terms of feedback interactions between the Calvin cycle and the C 4 cycle. Relations between electron transport and carbon assimilation are discussed in terms of the regulation of the supply of ATP and NADPH and the demands of carbon assimilation. In low light these relations differ in C 3 and C 4 plants. The lag in photosynthetic carbon assimilation in maize that follows a decrease in PFD has been analysed. The changes that occur in enzyme activities, metabolites and components of chlorophyll-fluorescence quenching following the transition from high to low light indicate that diminished production of ATP and NADPH is responsible for the lag in photosynthetic carbon assimilation and may reflect a stimulation of cyclic electron flow to make up a deficit in ATP.

scholarly journals Oncogenic pathways and the electron transport chain: a dangeROS liaison

2019 ◽  
Vol 122 (2) ◽  
pp. 168-181 ◽  
Author(s):  
Vittoria Raimondi ◽  
Francesco Ciccarese ◽  
Vincenzo Ciminale
Keyword(s):  
Electron Transport ◽  
Electron Transport Chain ◽  
Electron Flow ◽  
Second Messengers ◽  
Driver Mutations ◽  
Cell Phenotype ◽  
Oxygen Species ◽  
Hallmarks Of Cancer ◽  
Oncogenic Pathways ◽  
Transport Chain

AbstractDriver mutations in oncogenic pathways, rewiring of cellular metabolism and altered ROS homoeostasis are intimately connected hallmarks of cancer. Electrons derived from different metabolic processes are channelled into the mitochondrial electron transport chain (ETC) to fuel the oxidative phosphorylation process. Electrons leaking from the ETC can prematurely react with oxygen, resulting in the generation of reactive oxygen species (ROS). Several signalling pathways are affected by ROS, which act as second messengers controlling cell proliferation and survival. On the other hand, oncogenic pathways hijack the ETC, enhancing its ROS-producing capacity by increasing electron flow or by impinging on the structure and organisation of the ETC. In this review, we focus on the ETC as a source of ROS and its modulation by oncogenic pathways, which generates a vicious cycle that resets ROS levels to a higher homoeostatic set point, sustaining the cancer cell phenotype.

Sign in / Sign up

Export Citation Format

Share Document