scholarly journals Mitochondrial alternative oxidase pathway acts as an electron sink during photosynthetic induction in Rumex K-1 leaves

2021 ◽  
Author(s):  
D.D. CHENG ◽  
L.T. ZHANG
Keyword(s):  
Alternative Oxidase ◽  
Photosynthetic Induction ◽  
Electron Sink

Alternative oxidase from Arum and soybean: Its stabilization during purification

1996 ◽  
Vol 96 (4) ◽  
pp. 551-558 ◽  
Author(s):  
Qisen Zhang ◽  
Marcel H. N. Hoefnagel ◽  
Joseph T. Wiskich
Keyword(s):  
Alternative Oxidase

Multiple effects of inhibition of mitochondrial alternative oxidase pathway on photosynthetic apparatus in Rumex K-1 leaves

2012 ◽  
Vol 56 (2) ◽  
pp. 365-368 ◽  
Author(s):  
L.T. Zhang ◽  
H.Y. Gao ◽  
Z.S. Zhang ◽  
Z.C. Xue ◽  
Q.W. Meng
Keyword(s):  
Alternative Oxidase ◽  
Photosynthetic Apparatus

scholarly journals Alternative oxidase encoded by sequence-optimized and chemically-modified RNA transfected into mammalian cells is catalytically active

Gene Therapy ◽  
2021 ◽  
Author(s):  
Luca Giordano ◽  
Manish K. Aneja ◽  
Natascha Sommer ◽  
Nasim Alebrahimdehkordi ◽  
Alireza Seraji ◽  
...  
Keyword(s):  
Mammalian Cells ◽  
Alternative Oxidase ◽  
Chemically Modified ◽  
Lung Carcinoma Cells ◽  
Primary Mouse ◽  
Catalytically Active ◽  
Human Lung Carcinoma ◽  
Pulmonary Arterial ◽  
Metabolic Stresses ◽  
Mitochondrial Respiratory

AbstractPlants and other organisms, but not insects or vertebrates, express the auxiliary respiratory enzyme alternative oxidase (AOX) that bypasses mitochondrial respiratory complexes III and/or IV when impaired. Persistent expression of AOX from Ciona intestinalis in mammalian models has previously been shown to be effective in alleviating some metabolic stresses produced by respiratory chain inhibition while exacerbating others. This implies that chronic AOX expression may modify or disrupt metabolic signaling processes necessary to orchestrate adaptive remodeling, suggesting that its potential therapeutic use may be confined to acute pathologies, where a single course of treatment would suffice. One possible route for administering AOX transiently is AOX-encoding nucleic acid constructs. Here we demonstrate that AOX-encoding chemically-modified RNA (cmRNA), sequence-optimized for expression in mammalian cells, was able to support AOX expression in immortalized mouse embryonic fibroblasts (iMEFs), human lung carcinoma cells (A549) and primary mouse pulmonary arterial smooth muscle cells (PASMCs). AOX protein was detectable as early as 3 h after transfection, had a half-life of ~4 days and was catalytically active, thus supporting respiration and protecting against respiratory inhibition. Our data demonstrate that AOX-encoding cmRNA optimized for use in mammalian cells represents a viable route to investigate and possibly treat mitochondrial respiratory disorders.

scholarly journals Cyanobakterien als Biokatalysatoren

BIOspektrum ◽  
2021 ◽  
Vol 27 (2) ◽  
pp. 208-210
Author(s):  
Marc M. Nowaczyk ◽  
Hanna C. Grimm ◽  
Leen Assil-Companioni ◽  
Robert Kourist
Keyword(s):  
Natural Process ◽  
Oxygenic Photosynthesis ◽  
Phototrophic Microorganisms ◽  
Electron Sink ◽  
Pcc 6803

AbstractThe highly optimized natural process of oxygenic photosynthesis leads to the formation of redox equivalents, such as NADPH, that can be used to fuel heterologous biotransformations in phototrophic microorganisms. We investigated the reduction of 2-methylmaleimide by the ene-reductase YqjM in the cyanobacterium Synechocystis sp. PCC 6803 and doubled the productivity of the cells by inactivating flavodiironproteins (FDPs) as competing electron sink under self-shading conditions, reaching 18.3 mmol h−1 L−1.

scholarly journals Electron donation of non-oxide supports boosts O2 activation on nano-platinum catalysts

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Tao Gan ◽  
Jingxiu Yang ◽  
David Morris ◽  
Xuefeng Chu ◽  
Peng Zhang ◽  
...  
Keyword(s):  
Catalytic Oxidation ◽  
Pt Nanoparticles ◽  
Catalytic Performance ◽  
Nitrogen Vacancy ◽  
Innovative Strategy ◽  
Oxide Supports ◽  
Heterogeneous Catalytic ◽  
Highly Active ◽  
Electron Sink ◽  
Nitrogen Vacancies

AbstractActivation of O2 is a critical step in heterogeneous catalytic oxidation. Here, the concept of increased electron donors induced by nitrogen vacancy is adopted to propose an efficient strategy to develop highly active and stable catalysts for molecular O2 activation. Carbon nitride with nitrogen vacancies is prepared to serve as a support as well as electron sink to construct a synergistic catalyst with Pt nanoparticles. Extensive characterizations combined with the first-principles calculations reveal that nitrogen vacancies with excess electrons could effectively stabilize metallic Pt nanoparticles by strong p-d coupling. The Pt atoms and the dangling carbon atoms surround the vacancy can synergistically donate electrons to the antibonding orbital of the adsorbed O2. This synergistic catalyst shows great enhancement of catalytic performance and durability in toluene oxidation. The introduction of electron-rich non-oxide substrate is an innovative strategy to develop active Pt-based oxidation catalysts, which could be conceivably extended to a variety of metal-based catalysts for catalytic oxidation.

Weak O2 binding and strong H2O2 binding at the non-heme diiron center of Trypanosome Alternative Oxidase

2020 ◽  
pp. 148356
Author(s):  
Sotaro Yamasaki ◽  
Mitsuo Shoji ◽  
Megumi Kayanuma ◽  
Vladimir Sladek ◽  
Daniel Ken Inaoka ◽  
...  
Keyword(s):  
Alternative Oxidase ◽  
Trypanosome Alternative Oxidase ◽  
O2 Binding

scholarly journals Assessment of Voltage Influence in Carbon Dioxide Fixation Process by a Photo-Bioelectrochemical System under Photoheterotrophy

2021 ◽  
Vol 9 (3) ◽  
pp. 474
Author(s):  
Sara Díaz-Rullo Edreira ◽  
Silvia Barba ◽  
Ioanna A. Vasiliadou ◽  
Raúl Molina ◽  
Juan Antonio Melero ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Carbon Source ◽  
Future Development ◽  
Metabolic Pathways ◽  
Co2 Fixation ◽  
Oxygen Demand ◽  
Carbon Uptake ◽  
Bioelectrochemical System ◽  
Electron Sink ◽  
Soluble Carbon

Bioelectrochemical systems are a promising technology capable of reducing CO2 emissions, a renewable carbon source, using electroactive microorganisms for this purpose. Purple Phototrophic Bacteria (PPB) use their versatile metabolism to uptake external electrons from an electrode to fix CO2. In this work, the effect of the voltage (from −0.2 to −0.8 V vs. Ag/AgCl) on the metabolic CO2 fixation of a mixed culture of PPB under photoheterotrophic conditions during the oxidation of a biodegradable carbon source is demonstrated. The minimum voltage to fix CO2 was between −0.2 and −0.4 V. The Calvin–Benson–Bassham (CBB) cycle is the main electron sink at these voltages. However, lower voltages caused the decrease in the current intensity, reaching a minimum at −0.8 V (−4.75 mA). There was also a significant relationship between the soluble carbon uptake in terms of chemical oxygen demand and the electron consumption for the experiments performed at −0.6 and −0.8 V. These results indicate that the CBB cycle is not the only electron sink and some photoheterotrophic metabolic pathways are also being affected under electrochemical conditions. This behavior has not been tested before in photoheterotrophic conditions and paves the way for the future development of photobioelectrochemical systems under heterotrophic conditions.

scholarly journals Kinetic characterisation and inhibitor sensitivity of Candida albicans and Candida auris recombinant AOX expressed in a self-assembled proteoliposome system

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Alice C. Copsey ◽  
Mario R. O. Barsottini ◽  
Benjamin May ◽  
Fei Xu ◽  
Mary S. Albury ◽  
...  
Keyword(s):  
Candida Albicans ◽  
Future Development ◽  
Therapeutic Target ◽  
Fungicide Resistance ◽  
Alternative Oxidase ◽  
Antifungal Agents ◽  
Candida Auris ◽  
Novel Treatments ◽  
Membrane Bound ◽  
Self Assembled

AbstractCandidemia caused by Candida spp. is a serious threat in hospital settings being a major cause of acquired infection and death and a possible contributor to Covid-19 mortality. Candidemia incidence has been rising worldwide following increases in fungicide-resistant pathogens highlighting the need for more effective antifungal agents with novel modes of action. The membrane-bound enzyme alternative oxidase (AOX) promotes fungicide resistance and is absent in humans making it a desirable therapeutic target. However, the lipophilic nature of the AOX substrate (ubiquinol-10) has hindered its kinetic characterisation in physiologically-relevant conditions. Here, we present the purification and expression of recombinant AOXs from C. albicans and C. auris in a self-assembled proteoliposome (PL) system. Kinetic parameters (Km and Vmax) with respect to ubiquinol-10 have been determined. The PL system has also been employed in dose–response assays with novel AOX inhibitors. Such information is critical for the future development of novel treatments for Candidemia.

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