414 results match your criteria Biochimica et biophysica acta. Bioenergetics[Journal]


Identification of the electron donor to flavodiiron proteins in Synechocystis sp. PCC 6803 by in vivo spectroscopy.

Biochim Biophys Acta Bioenerg 2020 Jul 2:148256. Epub 2020 Jul 2.

Department of Biological and Environmental Sciences, Faculty of Agriculture, Kobe University, 1-1 Rokkodai, Nada, Kobe 657-8501, Japan.

Flavodiiron proteins (FDPs) of photosynthetic organisms play a photoprotective role by reducing oxygen to water and thus avoiding the accumulation of excess electrons on the photosystem I (PSI) acceptor side under stress conditions. In Synechocystis sp. PCC 6803 grown under high CO, both FDPs Flv1 and Flv3 are indispensable for oxygen reduction. Read More

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http://dx.doi.org/10.1016/j.bbabio.2020.148256DOI Listing

Transient depletion of transported metabolites in the streaming cytoplasm of Chara upon shading the long-distance transmission pathway.

Biochim Biophys Acta Bioenerg 2020 Jul 1:148257. Epub 2020 Jul 1.

Department of Biophysics, Faculty of Biology, Moscow State University, Moscow 119991, Russia. Electronic address:

Export of reducing power from chloroplasts to cytoplasm serves to balance the NADPH/ATP ratio that is optimal for CO assimilation. Rapid cytoplasmic streaming in characean algae conveys the exported metabolites downstream towards the shaded plastids where envelope transporters may operate for the import of reducing power in accordance with the direction of concentration gradients. Import of reducing equivalents by chloroplasts in the analyzed area transiently enhances the pulse-modulated chlorophyll fluorescence F' controlled by the redox state of photosystem II acceptor Q. Read More

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http://dx.doi.org/10.1016/j.bbabio.2020.148257DOI Listing

Regulation of light-induced H extrusion and uptake by cyanobacterial homologs of the plastidial FLAP1, DLDG1, and Ycf10 in Synechocystis sp. PCC6803.

Biochim Biophys Acta Bioenerg 2020 Jun 30;1861(10):148258. Epub 2020 Jun 30.

Department of Life Science and Technology, Tokyo Institute of Technology, Yokohama 226-8501, Japan. Electronic address:

Upon a dark-to-light transition, multiple species of cyanobacteria release a certain amount of H from the inside to the outside of their cells. Previous studies revealed the plasma membrane-localizing Proton exchange A (PxcA) is involved in the light-induced H extrusion in the cyanobacterium Synechocystis sp. PCC6803. Read More

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http://dx.doi.org/10.1016/j.bbabio.2020.148258DOI Listing

State transitions in cyanobacteria studied with picosecond fluorescence at room temperature.

Biochim Biophys Acta Bioenerg 2020 Jun 30:148255. Epub 2020 Jun 30.

Laboratory of Biophysics, Wageningen University, Wageningen, the Netherlands; MicroSpectroscopy Research Facility, Wageningen University, Wageningen, the Netherlands. Electronic address:

Cyanobacteria can rapidly regulate the relative activity of their photosynthetic complexes photosystem I and II (PSI and PSII) in response to changes in the illumination conditions. This process is known as state transitions. If PSI is preferentially excited, they go to state I whereas state II is induced either after preferential excitation of PSII or after dark adaptation. Read More

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http://dx.doi.org/10.1016/j.bbabio.2020.148255DOI Listing

Comparative assessment of purified saponins as permeabilization agents during respirometry.

Biochim Biophys Acta Bioenerg 2020 Jun 26;1861(10):148251. Epub 2020 Jun 26.

Chair of Molecular Nutritional Medicine, TUM School of Life Sciences, Technical University of Munich, Freising, Germany; EKFZ - Else Kröner-Fresenius Center for Nutritional Medicine, Technical University of Munich, Freising, Germany. Electronic address:

Saponins are a diverse group of secondary plant metabolites, some of which display hemolytic toxicity due to plasma membrane permeabilization. This feature is employed in biological applications for transferring hydrophilic molecules through cell membranes. Widely used commercial saponins include digitonin and saponins from soap tree bark, both of which constitute complex mixtures of little definition. Read More

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http://dx.doi.org/10.1016/j.bbabio.2020.148251DOI Listing

The controversy on the ancestral arsenite oxidizing enzyme; deducing evolutionary histories with phylogeny and thermodynamics.

Biochim Biophys Acta Bioenerg 2020 Jun 20;1861(10):148252. Epub 2020 Jun 20.

Aix-Marseille Univ., CNRS, BIP UMR 7281, FR 3479, IMM, 13402 Marseille Cedex 20, France. Electronic address:

The three presently known enzymes responsible for arsenic-using bioenergetic processes are arsenite oxidase (Aio), arsenate reductase (Arr) and alternative arsenite oxidase (Arx), all of which are molybdoenzymes from the vast group referred to as the Mo/W-bisPGD enzyme superfamily. Since arsenite is present in substantial amounts in hydrothermal environments, frequently considered as vestiges of primordial biochemistry, arsenite-based bioenergetics has long been predicted to be ancient. Conflicting scenarios, however, have been put forward proposing either Arr/Arx or Aio as operating in the ancestral metabolism. Read More

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http://dx.doi.org/10.1016/j.bbabio.2020.148252DOI Listing

Transport of Ca and Ca-dependent permeability transition in heart mitochondria in the early stages of Duchenne muscular dystrophy.

Biochim Biophys Acta Bioenerg 2020 Jun 20;1861(10):148250. Epub 2020 Jun 20.

Mari State University, pl. Lenina 1, Yoshkar-Ola, Mari El 424001, Russia; Institute of Theoretical and Experimental Biophysics, Russian Academy of Sciences, Institutskaya 3, Pushchino, Moscow Region 142290, Russia.

Duchenne muscular dystrophy (DMD) is a progressive skeletal muscle disease that is associated with severe cardiac complications in the late stages. Significant mitochondrial dysfunction is reportedly responsible for the development of cardiomyopathy with age. At the same time, adaptive changes in mitochondrial metabolism in cardiomyocytes were identified in the early stages of DMD. Read More

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http://dx.doi.org/10.1016/j.bbabio.2020.148250DOI Listing

The mitochondrial permeability transition pore: Is it formed by the ATP synthase, adenine nucleotide translocators or both?

Biochim Biophys Acta Bioenerg 2020 Jun 20;1861(10):148249. Epub 2020 Jun 20.

Department of Biochemistry, Facultad de Química, Universidad Nacional Autónoma de México, Mexico City 04510, Mexico. Electronic address:

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http://dx.doi.org/10.1016/j.bbabio.2020.148249DOI Listing

Structure and energy transfer pathways of the Dunaliella Salina photosystem I supercomplex.

Biochim Biophys Acta Bioenerg 2020 Jun 20;1861(10):148253. Epub 2020 Jun 20.

Department of Biochemistry and Molecular Biology, The George S. Wise Faculty of Life Sciences, Tel Aviv University, Tel Aviv 69978, Israel. Electronic address:

Oxygenic photosynthesis evolved more than 3 billion years ago in cyanobacteria. The increased complexity of photosystem I (PSI) became apparent from the high-resolution structures that were obtained for the complexes that were isolated from various organisms, ranging from cyanobacteria to plants. These complexes are all evolutionarily linked. Read More

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http://dx.doi.org/10.1016/j.bbabio.2020.148253DOI Listing

Kinetic and structural characterisation of the ubiquinol-binding site and oxygen reduction by the trypanosomal alternative oxidase.

Biochim Biophys Acta Bioenerg 2020 Jun 18;1861(10):148247. Epub 2020 Jun 18.

Biochemistry and Biomedicine, School of Life Sciences, University of Sussex, Falmer, Brighton BN1 9QG, United Kingdom.

The alternative oxidase (AOX) is a monotopic di‑iron carboxylate protein which acts as a terminal respiratory chain oxidase in a variety of plants, fungi and protists. Of particular importance is the finding that both emerging infectious diseases caused by human and plant fungal pathogens, the majority of which are multi-drug resistant, appear to be dependent upon AOX activity for survival. Since AOX is absent in mammalian cells, AOX is considered a viable therapeutic target for the design of specific fungicidal and anti-parasitic drugs. Read More

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http://dx.doi.org/10.1016/j.bbabio.2020.148247DOI Listing

The primary donor of far-red Photosystem II: Chl or P?

Biochim Biophys Acta Bioenerg 2020 Jun 18:148248. Epub 2020 Jun 18.

Research School of Chemistry, Australian National University, Canberra 2600, Australia. Electronic address:

Far-red light (FRL) Photosystem II (PSII) isolated from Chroococcidiopsis thermalis is studied using parallel analyses of low-temperature absorption, circular dichroism (CD) and magnetic circular dichroism (MCD) spectroscopies in conjunction with fluorescence measurements. This extends earlier studies (Nurnberg et al 2018 Science 360 (2018) 1210-1213). We confirm that the chlorophyll absorbing at 726 nm is the primary electron donor. Read More

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http://dx.doi.org/10.1016/j.bbabio.2020.148248DOI Listing

Primary electron transfer in Rhodobacter sphaeroides R-26 reaction centers under dehydration conditions.

Biochim Biophys Acta Bioenerg 2020 Jun 11;1861(10):148238. Epub 2020 Jun 11.

Institute of Basic Biological Problems of the Russian Academy of Sciences, Federal Research Center "Pushchino Scientific Center for Biological Research of the Russian Academy of Sciences", 142290 Pushchino, Moscow Region, Russian Federation. Electronic address:

The photoinduced charge separation in Q-depleted reaction centers (RCs) from Rhodobacter sphaeroides R-26 in solid air-dried and vacuum-dried (~10 Torr) films, obtained in the presence of detergent n-dodecyl-β-D-maltoside (DM), is characterized using ultrafast transient absorption spectroscopy. It is shown that drying of RC-DM complexes is accompanied by reversible blue shifts of the ground-state absorption bands of the pigment ensemble, which suggest that no dehydration-induced structural destruction of RCs occurs in both types of films. In air-dried films, electron transfer from the excited primary electron donor P to the photoactive bacteriopheophytin H proceeds in 4. Read More

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http://dx.doi.org/10.1016/j.bbabio.2020.148238DOI Listing

Identifying the proton loading site cluster in the ba cytochrome c oxidase that loads and traps protons.

Biochim Biophys Acta Bioenerg 2020 Jun 10;1861(10):148239. Epub 2020 Jun 10.

Department of Physics, City College of New York, 160 Convent Avenue, New York, NY 10031, USA; Department of Physics, Graduate Center, City University of New York, 365 Fifth Avenue, New York, NY 10016, USA; Department of Chemistry, Graduate Center, City University of New York, 365 Fifth Avenue, New York, NY 10016, USA. Electronic address:

Cytochrome c Oxidase (CcO) is the terminal electron acceptor in aerobic respiratory chain, reducing O to water. The released free energy is stored by pumping protons through the protein, maintaining the transmembrane electrochemical gradient. Protons are held transiently in a proton loading site (PLS) that binds and releases protons driven by the electron transfer reaction cycle. Read More

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http://dx.doi.org/10.1016/j.bbabio.2020.148239DOI Listing

Hydrogen bond network analysis reveals the pathway for the proton transfer in the E-channel of T. thermophilus Complex I.

Biochim Biophys Acta Bioenerg 2020 Jun 9;1861(10):148240. Epub 2020 Jun 9.

Department of Physics, City College of New York, New York 10031, USA; Department of Physics, The Graduate Center, City University of New York, New York 10016, USA; Department of Chemistry, The Graduate Center, City University of New York, New York 10016, USA. Electronic address:

Complex I, NADH-ubiquinone oxidoreductase, is the first enzyme in the mitochondrial and bacterial aerobic respiratory chain. It pumps four protons through four transiently open pathways from the high pH, negative, N-side of the membrane to the positive, P-side driven by the exergonic transfer of electrons from NADH to a quinone. Three protons transfer through subunits descended from antiporters, while the fourth, E-channel is unique. Read More

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http://dx.doi.org/10.1016/j.bbabio.2020.148240DOI Listing

The water-water cycle is more effective in regulating redox state of photosystem I under fluctuating light than cyclic electron transport.

Biochim Biophys Acta Bioenerg 2020 Sep 30;1861(9):148235. Epub 2020 May 30.

Key Laboratory of Economic Plants and Biotechnology, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, Yunnan 650201, China. Electronic address:

Photosynthetic electron flux from water via photosystem II (PSII) and PSI to oxygen (water-water cycle) may act as an alternative electron sink under fluctuating light in angiosperms. We measured the P700 redox kinetics and electrochromic shift signal under fluctuating light in 11 Camellia species and tobacco leaves. Upon dark-to-light transition, these Camellia species showed rapid re-oxidation of P700. Read More

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http://dx.doi.org/10.1016/j.bbabio.2020.148235DOI Listing
September 2020

Modulation of the electron-proton coupling at cytochrome a by the ligation of the oxidized catalytic center in bovine cytochrome c oxidase.

Biochim Biophys Acta Bioenerg 2020 Sep 30;1861(9):148237. Epub 2020 May 30.

Center for Interdisciplinary Biosciences, Technology and Innovation Park, University of P. J. Safarik, Jesenna 5, 041 54, Kosice, Slovak Republic. Electronic address:

Cytochrome a was suggested as the key redox center in the proton pumping process of bovine cytochrome c oxidase (CcO). Recent studies showed that both the structure of heme a and its immediate vicinity are sensitive to the ligation and the redox state of the distant catalytic center composed of iron of cytochrome a (Fe) and copper (Cu). Here, the influence of the ligation at the oxidized Fe-Cu center on the electron-proton coupling at heme a was examined in the wide pH range (6. Read More

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http://dx.doi.org/10.1016/j.bbabio.2020.148237DOI Listing
September 2020

Stabilization of Photosystem II by the PsbT protein impacts photodamage, repair and biogenesis.

Biochim Biophys Acta Bioenerg 2020 May 30:148234. Epub 2020 May 30.

Department of Biochemistry, University of Otago, Dunedin 9054, New Zealand. Electronic address:

Photosystem II (PS II) catalyzes the light-driven process of water splitting in oxygenic photosynthesis. Four core membrane-spanning proteins, including D1 that binds the majority of the redox-active co-factors, are surrounded by 13 low-molecular-weight (LMW) proteins. We previously observed that deletion of the LMW PsbT protein in the cyanobacterium Synechocystis sp. Read More

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http://dx.doi.org/10.1016/j.bbabio.2020.148234DOI Listing

X-ray structure of C-phycocyanin from Galdieria phlegrea: Determinants of thermostability and comparison with a C-phycocyanin in the entire phycobilisome.

Biochim Biophys Acta Bioenerg 2020 Sep 30;1861(9):148236. Epub 2020 May 30.

Department of Chemical Sciences, University of Naples Federico II, Naples, Italy.. Electronic address:

Galdieria phlegrea is a polyextremophilic red alga belonging to Cyanidiophyceae. Galdieria phlegrea C-phycocyanin (GpPC), an abundant light-harvesting pigment with an important role in energy capture and transfer to photosystems, is the C-phycocyanin (C-PC) with the highest thermal stability described so far. GpPC also presents interesting antioxidant and anticancer activities. Read More

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http://dx.doi.org/10.1016/j.bbabio.2020.148236DOI Listing
September 2020

Charge polarization imposed by the binding site facilitates enzymatic redox reactions of quinone.

Biochim Biophys Acta Bioenerg 2020 May 5;1861(8):148216. Epub 2020 May 5.

Department of Molecular Biophysics, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, Kraków 30387, Poland. Electronic address:

Quinone reduction site (Q) of cytochrome bc represents one of the canonical sites used to explore the enzymatic redox reactions involving semiquinone (SQ) states. However, the mechanism by which Q allows the completion of quinone reduction during the sequential transfers of two electrons from the adjacent heme b and two protons to C1- and C4-carbonyl remains unclear. Here we established that the SQ coupled to an oxidized heme b is a dominant intermediate of catalytic forward reaction and, contrary to the long-standing assumption, represents a significant population of SQ detected across pH 5-9. Read More

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http://dx.doi.org/10.1016/j.bbabio.2020.148216DOI Listing

CpeY is a phycoerythrobilin lyase for cysteine 82 of the phycoerythrin I α-subunit in marine Synechococcus.

Biochim Biophys Acta Bioenerg 2020 Apr 29;1861(8):148215. Epub 2020 Apr 29.

Department of Biological Sciences, University of New Orleans, New Orleans, LA 70148, USA. Electronic address:

Marine Synechococcus are widespread in part because they are efficient at harvesting available light using their complex antenna, or phycobilisome, composed of multiple phycobiliproteins and bilin chromophores. Over 40% of Synechococcus strains are predicted to perform a type of chromatic acclimation that alters the ratio of two chromophores, green-light-absorbing phycoerythrobilin and blue-light-absorbing phycourobilin, to optimize light capture by phycoerythrin in the phycobilisome. Lyases are enzymes which catalyze the addition of bilin chromophores to specific cysteine residues on phycobiliproteins and are involved in chromatic acclimation. Read More

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http://dx.doi.org/10.1016/j.bbabio.2020.148215DOI Listing

Structural dynamics in the C terminal domain homolog of orange carotenoid Protein reveals residues critical for carotenoid uptake.

Biochim Biophys Acta Bioenerg 2020 Apr 30;1861(8):148214. Epub 2020 Apr 30.

Schulich Faculty of Chemistry, Technion, Haifa 3200003, Israel; Grand Technion Energy Program (GTEP), Technion, Haifa 3200003, Israel. Electronic address:

The structural features enabling carotenoid translocation between molecular entities in nature is poorly understood. Here, we present the three-dimensional X-ray structure of an expanded oligomeric state of the C-terminal domain homolog (CTDH) of the orange carotenoid protein, a key water-soluble protein in cyanobacterial photosynthetic photo-protection, at 2.9 Å resolution. Read More

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http://dx.doi.org/10.1016/j.bbabio.2020.148214DOI Listing

Remodeling of photosynthetic electron transport in Synechocystis sp. PCC 6803 for future hydrogen production from water.

Biochim Biophys Acta Bioenerg 2020 Apr 24;1861(8):148208. Epub 2020 Apr 24.

Plant Biochemistry, Faculty of Biology and Biotechnology, Ruhr-University Bochum, 44780 Bochum, Germany. Electronic address:

Photosynthetic microorganisms such as the cyanobacterium Synechocystis sp. PCC 6803 (Synechocystis) can be exploited for the light-driven synthesis of valuable compounds. Thermodynamically, it is most beneficial to branch-off photosynthetic electrons at ferredoxin (Fd), which provides electrons for a variety of fundamental metabolic pathways in the cell, with the ferredoxin-NADP Oxido-Reductase (FNR, PetH) being the main target. Read More

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http://dx.doi.org/10.1016/j.bbabio.2020.148208DOI Listing

NDUFS4 deletion triggers loss of NDUFA12 in Ndufs4 mice and Leigh syndrome patients: A stabilizing role for NDUFAF2.

Biochim Biophys Acta Bioenerg 2020 Apr 23;1861(8):148213. Epub 2020 Apr 23.

Department of Biochemistry, Radboud Institute for Molecular Life Sciences, Radboud Center for Mitochondrial Medicine, Radboudumc, Nijmegen, the Netherlands. Electronic address:

Mutations in NDUFS4, which encodes an accessory subunit of mitochondrial oxidative phosphorylation (OXPHOS) complex I (CI), induce Leigh syndrome (LS). LS is a poorly understood pediatric disorder featuring brain-specific anomalies and early death. To study the LS pathomechanism, we here compared OXPHOS proteomes between various Ndufs4 mouse tissues. Read More

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http://dx.doi.org/10.1016/j.bbabio.2020.148213DOI Listing

Realtime kinetics of the light driven steps of photosynthetic water oxidation in living organisms by "stroboscopic" fluorometry.

Biochim Biophys Acta Bioenerg 2020 Apr 19;1861(8):148212. Epub 2020 Apr 19.

Waksman Institute of Microbiology, Rutgers University, Piscataway, NJ 08854, United States of America; Department of Chemistry and Chemical Biology, Rutgers University, Piscataway, NJ 08854, United States of America. Electronic address:

We develop a rapid "stroboscopic" fluorescence induction method, using the fast repetition rate fluorometry (FRRF) technique, to measure changes in the quantum yield of light emission from chlorophyll in oxygenic photosynthesis arising from competition with primary photochemical charge separation (P* ➔ PQ). This method determines the transit times of electrons that pass through PSII during the successive steps in the catalytic cycle of water oxidation/O formation (S states) and plastoquinone reduction in any oxygenic phototroph (in vivo or in vitro). We report the first measurements from intact living cells, illustrated by a eukaryotic alga (Nannochloropsis oceanica). Read More

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http://dx.doi.org/10.1016/j.bbabio.2020.148212DOI Listing

Deactivation of mitochondrial NADH:ubiquinone oxidoreductase (respiratory complex I): Extrinsically affecting factors.

Biochim Biophys Acta Bioenerg 2020 Apr 18;1861(8):148207. Epub 2020 Apr 18.

Department of Biochemistry, School of Biology, M.V. Lomonosov Moscow State University, Moscow 119234, Russian Federation. Electronic address:

Mitochondrial NADH:ubiquinone oxidoreductase (proton translocating respiratory complex I) serves several essential functions in cell metabolism: it maintains the intramitochondrial NADH/NAD ratio, contributes to generation of the proton-motive force, and participates in physiological and/or pathophysiological production of so-called reactive oxygen species. A characteristic feature of complex I is a slow, compared with its catalytic turnover, transformation to its inactive (deactivated) state, a phenomenon operationally called A/D transition. Here we report data on several extrinsic factors affecting deactivation as observed in coupled or uncoupled bovine heart submitochondrial particles. Read More

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http://dx.doi.org/10.1016/j.bbabio.2020.148207DOI Listing

Photosynthetic characterization of flavodoxin-expressing tobacco plants reveals a high light acclimation-like phenotype.

Biochim Biophys Acta Bioenerg 2020 Apr 18;1861(8):148211. Epub 2020 Apr 18.

Instituto de Biología Molecular y Celular de Rosario (IBR-UNR/CONICET), Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario (UNR), 2000 Rosario, Argentina. Electronic address:

Flavodoxins are electron carrier flavoproteins present in bacteria and photosynthetic microorganisms which duplicate the functional properties of iron-sulphur containing ferredoxins and replace them under adverse environmental situations that lead to ferredoxin decline. When expressed in plant chloroplasts, flavodoxin complemented ferredoxin deficiency and improved tolerance to multiple sources of biotic, abiotic and xenobiotic stress. Analysis of flavodoxin-expressing plants grown under normal conditions, in which the two carriers are present, revealed phenotypic effects unrelated to ferredoxin replacement. Read More

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http://dx.doi.org/10.1016/j.bbabio.2020.148211DOI Listing

Functional characterization of the mitochondrial uncoupling proteins from the white shrimp Litopenaeus vannamei.

Biochim Biophys Acta Bioenerg 2020 Apr 16;1861(8):148209. Epub 2020 Apr 16.

Bioenergetics and Molecular Genetics Lab, Centro de Investigacion en Alimentacion y Desarrollo, A. C. Carretera Gustavo Astiazaran Rosas 36, 83304 Hermosillo, Sonora, Mexico. Electronic address:

Mitochondrial uncoupling proteins (UCPs) play an essential role in dissipating the proton gradient and controlling the mitochondrial inner membrane potential. When active, UCPs promote proton leak across the inner membrane, oxidative phosphorylation uncoupling, oxygen uptake increase and decrease the ATP synthesis. Invertebrates possess only isoforms UCP4 and UCP5, however, the role of these proteins is not clear in most species since it may depend on the physiological needs of each animal. Read More

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http://dx.doi.org/10.1016/j.bbabio.2020.148209DOI Listing

Unfolding pathway and intermolecular interactions of the cytochrome subunit in the bacterial photosynthetic reaction center.

Biochim Biophys Acta Bioenerg 2020 Apr 17;1861(8):148204. Epub 2020 Apr 17.

Institute of Integrative Biology, University of Liverpool, Liverpool L69 7ZB, United Kingdom; College of Marine Life Sciences, and Frontiers Science Center for Deep Ocean Multispheres and Earth System, Ocean University of China, Qingdao 266003, China. Electronic address:

Precise folding of photosynthetic proteins and organization of multicomponent assemblies to form functional entities are fundamental to efficient photosynthetic electron transfer. The bacteriochlorophyll b-producing purple bacterium Blastochloris viridis possesses a simplified photosynthetic apparatus. The light-harvesting (LH) antenna complex surrounds the photosynthetic reaction center (RC) to form the RC-LH1 complex. Read More

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http://dx.doi.org/10.1016/j.bbabio.2020.148204DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7322399PMC

The two light-harvesting membrane chromoproteins of Thermochromatium tepidum expose distinct robustness against temperature and pressure.

Biochim Biophys Acta Bioenerg 2020 Apr 17;1861(8):148205. Epub 2020 Apr 17.

Institute of Physics, University of Tartu, W. Ostwald Str. 1, 50411 Tartu, Estonia; Institute of Molecular and Cell Biology, University of Tartu, Riia 23, 51010 Tartu, Estonia; Estonian Academy of Sciences, Kohtu 6, 10130 Tallinn, Estonia. Electronic address:

An increased robustness against high temperature and the much red-shifted near-infrared absorption spectrum of excitons in the LH1-RC core pigment-protein complex from the thermophilic photosynthetic purple sulfur bacterium Thermochromatium tepidum has recently attracted much interest. In the present work, thermal and hydrostatic pressure stability of the peripheral LH2 and core LH1-RC complexes from this bacterium were in parallel investigated by various optical spectroscopy techniques applied over a wide spectral range from far-ultraviolet to near-infrared. In contrast to expectations, very distinct robustness of the complexes was established, while the sturdiness of LH2 surpassed that of LH1-RC both with respect to temperatures between 288 and 360 K, and pressures between 1 bar and 14 kbar. Read More

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http://dx.doi.org/10.1016/j.bbabio.2020.148205DOI Listing

Harvesting far-red light: Functional integration of chlorophyll f into Photosystem I complexes of Synechococcus sp. PCC 7002.

Biochim Biophys Acta Bioenerg 2020 Apr 17;1861(8):148206. Epub 2020 Apr 17.

Department of Physics and Astronomy and LaserLaB, Faculty of Science, Vrije Universiteit Amsterdam, De Boelelaan 1081, 1081 HV Amsterdam, the Netherlands. Electronic address:

The heterologous expression of the far-red absorbing chlorophyll (Chl) f in organisms that do not synthesize this pigment has been suggested as a viable solution to expand the solar spectrum that drives oxygenic photosynthesis. In this study, we investigate the functional binding of Chl f to the Photosystem I (PSI) of the cyanobacterium Synechococcus 7002, which has been engineered to express the Chl f synthase gene. By optimizing growth light conditions, one-to-four Chl f pigments were found in the complexes. Read More

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http://dx.doi.org/10.1016/j.bbabio.2020.148206DOI Listing
April 2020
5.353 Impact Factor

H hyperfine spectroscopy and DFT modeling unveil the demethylmenasemiquinone binding mode to E. coli nitrate reductase A (NarGHI).

Biochim Biophys Acta Bioenerg 2020 Apr 17;1861(8):148203. Epub 2020 Apr 17.

Aix Marseille Univ, CNRS, BIP, Marseille, France. Electronic address:

The quinol oxidation site Q in E. coli respiratory nitrate reductase A (EcNarGHI) reacts with the three isoprenoid quinones naturally synthesized by the bacterium, i.e. Read More

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http://dx.doi.org/10.1016/j.bbabio.2020.148203DOI Listing

Mitochondria-targeted 1,4-naphthoquinone (SkQN) is a powerful prooxidant and cytotoxic agent.

Biochim Biophys Acta Bioenerg 2020 Apr 17;1861(8):148210. Epub 2020 Apr 17.

A.N. Belozersky Institute of Physico-Chemical Biology, M.V. Lomonosov Moscow State University, Russian Federation. Electronic address:

An increase in the production of reactive oxygen species (ROS) in mitochondria due to targeted delivery of redox active compounds may be useful in studies of modulation of cell functions by mitochondrial ROS. Recently, the mitochondria-targeted derivative of menadione (MitoK) was synthesized. However, MitoK did not induce mitochondrial ROS production and lipid peroxidation while exerting significant cytotoxic action. Read More

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http://dx.doi.org/10.1016/j.bbabio.2020.148210DOI Listing

TMEM70 functions in the assembly of complexes I and V.

Biochim Biophys Acta Bioenerg 2020 Apr 7;1861(8):148202. Epub 2020 Apr 7.

Department of Paediatrics, Radboud Centre for Mitochondrial Medicine, Radboud University Medical Centre, Nijmegen, the Netherlands.

Protein complexes from the oxidative phosphorylation (OXPHOS) system are assembled with the help of proteins called assembly factors. We here delineate the function of the inner mitochondrial membrane protein TMEM70, in which mutations have been linked to OXPHOS deficiencies, using a combination of BioID, complexome profiling and coevolution analyses. TMEM70 interacts with complex I and V and for both complexes the loss of TMEM70 results in the accumulation of an assembly intermediate followed by a reduction of the next assembly intermediate in the pathway. Read More

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http://dx.doi.org/10.1016/j.bbabio.2020.148202DOI Listing

The two CO-dehydrogenases of Thermococcus sp. AM4.

Biochim Biophys Acta Bioenerg 2020 07 21;1861(7):148188. Epub 2020 Mar 21.

Aix-Marseille Université, CNRS, BIP UMR 7281, 31 Chemin J. AIGUIER, CS70071, F-13402 Marseille Cedex 20, (France). Electronic address:

Ni-containing CO-dehydrogenases (CODHs) allow some microorganisms to couple ATP synthesis to CO oxidation, or to use either CO or CO as a source of carbon. The recent detailed characterizations of some of them have evidenced a great diversity in terms of catalytic properties and resistance to O. In an effort to increase the number of available CODHs, we have heterologously produced in Desulfovibrio fructosovorans, purified and characterized the two CooS-type CODHs (CooS1 and CooS2) from the hyperthermophilic archaeon Thermococcus sp. Read More

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http://dx.doi.org/10.1016/j.bbabio.2020.148188DOI Listing

Zeaxanthin independence of photophysics in light-harvesting complex II in a membrane environment.

Biochim Biophys Acta Bioenerg 2020 06 20;1861(5-6):148115. Epub 2020 Mar 20.

Department of Chemistry, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA 02139, USA. Electronic address:

Green plants protect against photodamage by dissipating excess energy in a process called non-photochemical quenching (NPQ). In vivo, NPQ is activated by a drop in the luminal pH of the thylakoid membrane that triggers conformational changes of the antenna complexes, which activate quenching channels. The drop in pH also triggers de-epoxidation of violaxanthin, one of the carotenoids bound within the antenna complexes, into zeaxanthin, and so the amplitude of NPQ in vivo has been shown to increase in the presence of zeaxanthin. Read More

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http://dx.doi.org/10.1016/j.bbabio.2019.148115DOI Listing

Kinetic advantage of forming respiratory supercomplexes.

Biochim Biophys Acta Bioenerg 2020 07 19;1861(7):148193. Epub 2020 Mar 19.

Department of Biochemistry and Biophysics, The Arrhenius Laboratories for Natural Sciences, Stockholm University, SE-106 91 Stockholm, Sweden. Electronic address:

Components of respiratory chains in mitochondria and some aerobic bacteria assemble into larger, multiprotein membrane-bound supercomplexes. Here, we address the functional significance of supercomplexes composed of respiratory-chain complexes III and IV. Complex III catalyzes oxidation of quinol and reduction of water-soluble cytochrome c (cyt c), while complex IV catalyzes oxidation of the reduced cyt c and reduction of dioxygen to water. Read More

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http://dx.doi.org/10.1016/j.bbabio.2020.148193DOI Listing

Spectral tuning of light-harvesting complex II in the siphonous alga Bryopsis corticulans and its effect on energy transfer dynamics.

Biochim Biophys Acta Bioenerg 2020 07 20;1861(7):148191. Epub 2020 Mar 20.

Biological Research Centre, Szeged, Hungary. Electronic address:

Light-harvesting complex II (LHCII) from the marine green macroalga Bryopsis corticulans is spectroscopically characterized to understand the structural and functional changes resulting from adaptation to intertidal environment. LHCII is homologous to its counterpart in land plants but has a different carotenoid and chlorophyll (Chl) composition. This is reflected in the steady-state absorption, fluorescence, linear dichroism, circular dichroism and anisotropic circular dichroism spectra. Read More

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http://dx.doi.org/10.1016/j.bbabio.2020.148191DOI Listing

F-ATP-ase of Escherichia coli membranes: The ubiquitous MgADP-inhibited state and the inhibited state induced by the ε-subunit's C-terminal domain are mutually exclusive.

Biochim Biophys Acta Bioenerg 2020 07 17;1861(7):148189. Epub 2020 Mar 17.

Department of Biochemistry & Molecular Biology, SUNY Upstate Medical University, 750 E Adams St, Syracuse, NY 13210, USA. Electronic address:

ATP synthases are important energy-coupling, rotary motor enzymes in all kingdoms of life. In all F-type ATP synthases, the central rotor of the catalytic F complex is composed of the γ subunit and the N-terminal domain (NTD) of the ε subunit. In the enzymes of diverse bacteria, the C-terminal domain of ε (εCTD) can undergo a dramatic conformational change to trap the enzyme in a transiently inactive state. Read More

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http://dx.doi.org/10.1016/j.bbabio.2020.148189DOI Listing

Infrared spectroscopic analysis on structural changes around the protonated Schiff base upon retinal isomerization in light-driven sodium pump KR2.

Biochim Biophys Acta Bioenerg 2020 07 17;1861(7):148190. Epub 2020 Mar 17.

Department of Life Science and Applied Chemistry, Nagoya Institute of Technology, Showa-ku, Nagoya 466-8555, Japan; OptoBioTechnology Research Center, Nagoya Institute of Technology, Showa-ku, Nagoya 466-8555, Japan. Electronic address:

Krokinobacter rhodopsin 2 (KR2) was discovered as the first light-driven sodium pumping rhodopsin (NaR) in 2013, which contains unique amino acid residues on C-helix (N112, D116, and Q123), referred to as an NDQ motif. Based on the recent X-ray crystal structures of KR2, the sodium transport pathway has been investigated by various methods. However, due to complicated structural information around the protonated Schiff base (PRSB) region in the dark state and lack of structural information in the intermediates with sodium bound in KR2, detailed sodium pump mechanism is still unclear. Read More

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http://dx.doi.org/10.1016/j.bbabio.2020.148190DOI Listing

Characterization of human mitochondrial PDSS and COQ proteins and their roles in maintaining coenzyme Q levels and each other's stability.

Biochim Biophys Acta Bioenerg 2020 07 17;1861(7):148192. Epub 2020 Mar 17.

Department of Medical Biotechnology and Laboratory Science, College of Medicine, Chang Gung University, Taoyuan, Taiwan.

Mutations of many PDSS and COQ genes are associated with primary coenzyme Q (CoQ) deficiency, whereas mitochondrial DNA (mtDNA) mutations might cause secondary CoQ deficiency. Previously, we found that COQ5 and COQ9 proteins are present in different protein complexes in the mitochondria in human 143B cells and demonstrated that COQ5 and COQ9 knockdown suppresses CoQ levels. In the present study, we characterized other PDSS and COQ proteins and examined possible crosstalk among various PDSS and COQ proteins. Read More

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http://dx.doi.org/10.1016/j.bbabio.2020.148192DOI Listing

Evidence that chlorophyll f functions solely as an antenna pigment in far-red-light photosystem I from Fischerella thermalis PCC 7521.

Biochim Biophys Acta Bioenerg 2020 06 14;1861(5-6):148184. Epub 2020 Mar 14.

Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, 16802, 108 Althouse Laboratory, University Park, USA; Department of Chemistry, the Pennsylvania State University, University Park, 16802, 104 Chemistry Building, University Park, USA.

The Photosystem I (PSI) reaction center in cyanobacteria is comprised of ~96 chlorophyll (Chl) molecules, including six specialized Chl molecules denoted Chl1A/Chl1B (P), Chl2A/Chl2B, and Chl3A/Chl3B that are arranged in two branches and function in primary charge separation. It has recently been proposed that PSI from Chroococcidiopsis thermalis (Nürnberg et al. (2018) Science 360, 1210-1213) and Fischerella thermalis PCC 7521 (Hastings et al. Read More

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http://dx.doi.org/10.1016/j.bbabio.2020.148184DOI Listing

PsbS contributes to photoprotection in Chlamydomonas reinhardtii independently of energy dissipation.

Biochim Biophys Acta Bioenerg 2020 06 12;1861(5-6):148183. Epub 2020 Mar 12.

Plant Biochemistry, Heinrich-Heine-Universität Düsseldorf, 40225 Düsseldorf, Germany. Electronic address:

Photosynthetic organisms are frequently exposed to excess light conditions and hence to photo-oxidative stress. To counteract photo-oxidative damage, land plants and most algae make use of non- photochemical quenching (NPQ) of excess light energy, in particular the rapidly inducible and relaxing qE-mechanism. In vascular plants, the constitutively active PsbS protein is the key regulator of qE. Read More

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http://dx.doi.org/10.1016/j.bbabio.2020.148183DOI Listing

Charge transfer states in phycobilisomes.

Biochim Biophys Acta Bioenerg 2020 07 12;1861(7):148187. Epub 2020 Mar 12.

Department of Physics, University of Pretoria, Pretoria 0023, South Africa; Faculty of Science, Vrije Universiteit Amsterdam, Amsterdam 1081 HV, the Netherlands. Electronic address:

Phycobilisomes (PBs) absorb light and supply downstream photosynthetic processes with excitation energy in many cyanobacteria and algae. In response to a sudden increase in light intensity, excess excitation energy is photoprotectively dissipated in PBs by means of the orange carotenoid protein (OCP)-related mechanism or via a light-activated intrinsic decay channel. Recently, we have identified that both mechanisms are associated with far-red emission states. Read More

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http://dx.doi.org/10.1016/j.bbabio.2020.148187DOI Listing

Proton motive function of the terminal antiporter-like subunit in respiratory complex I.

Biochim Biophys Acta Bioenerg 2020 07 19;1861(7):148185. Epub 2020 Mar 19.

Department of Physics, University of Helsinki, Helsinki, Finland; Institute of Biotechnology, University of Helsinki, Helsinki, Finland. Electronic address:

In the aerobic respiratory chains of many organisms, complex I functions as the first electron input. By reducing ubiquinone (Q) to ubiquinol, it catalyzes the translocation of protons across the membrane as far as ~200 Å from the site of redox reactions. Despite significant amount of structural and biochemical data, the details of redox coupled proton pumping in complex I are poorly understood. Read More

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http://dx.doi.org/10.1016/j.bbabio.2020.148185DOI Listing

Excitation dynamics and relaxation in the major antenna of a marine green alga Bryopsis corticulans.

Biochim Biophys Acta Bioenerg 2020 06 11;1861(5-6):148186. Epub 2020 Mar 11.

Department of Chemistry, Renmin University of China, Beijing 100872, China. Electronic address:

The light-harvesting complexes II (LHCIIs) of spinach and Bryopsis corticulans as a green alga are similar in structure, but differ in carotenoid (Car) and chlorophyll (Chl) compositions. Carbonyl Cars siphonein (Spn) and siphonaxanthin (Spx) bind to B. corticulans LHCII likely in the sites as a pair of lutein (Lut) molecules bind to spinach LHCII in the central domain. Read More

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http://dx.doi.org/10.1016/j.bbabio.2020.148186DOI Listing

Timing of dimerization of the bc complex during mitochondrial respiratory chain assembly.

Biochim Biophys Acta Bioenerg 2020 06 29;1861(5-6):148177. Epub 2020 Feb 29.

Department of Biochemistry and Biophysics, Stockholm University, SE-10691 Stockholm, Sweden. Electronic address:

The mitochondrial bc complex plays an important role in mitochondrial respiration. It transfers electrons from ubiquinol to the soluble electron shuttle cytochrome c and thereby contributes to the proton motive force across the inner mitochondrial membrane. In the yeast Saccharomyces cerevisiae, each monomer consists of three catalytic and seven accessory subunits. Read More

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http://dx.doi.org/10.1016/j.bbabio.2020.148177DOI Listing

What can we still learn from the electrochromic band-shifts in Photosystem II?

Biochim Biophys Acta Bioenerg 2020 06 19;1861(5-6):148176. Epub 2020 Feb 19.

Proteo-Science Research Center and Graduate School of Science and Technology, Ehime University, Bunkyo-cho, Matsuyama, Ehime 790-8577, Japan.

Electrochromic band-shifts have been investigated in Photosystem II (PSII) from Thermosynechoccocus elongatus. Firstly, by using Mn-depleted PsbA1-PSII and PsbA3-PSII in which the Q absorption of Phe differs, a band-shift in the Q region of Phe centered at ~ 544 nm has been identified upon the oxidation, at pH 8.6, of Tyr. Read More

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http://dx.doi.org/10.1016/j.bbabio.2020.148176DOI Listing

The carboxy-terminal insert in the Q-loop is needed for functionality of Escherichia coli cytochrome bd-I.

Biochim Biophys Acta Bioenerg 2020 06 12;1861(5-6):148175. Epub 2020 Feb 12.

Department of Molecular Cell Biology, Amsterdam Institute for Molecules, Medicines and Systems, Faculty of Sciences, Vrije Universiteit Amsterdam, De Boelelaan 1108, 1081 HZ Amsterdam, the Netherlands. Electronic address:

Cytochrome bd, a component of the prokaryotic respiratory chain, is important under physiological stress and during pathogenicity. Electrons from quinol substrates are passed on via heme groups in the CydA subunit and used to reduce molecular oxygen. Close to the quinol binding site, CydA displays a periplasmic hydrophilic loop called Q-loop that is essential for quinol oxidation. Read More

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http://dx.doi.org/10.1016/j.bbabio.2020.148175DOI Listing

Engineering the photoactive orange carotenoid protein with redox-controllable structural dynamics and photoprotective function.

Biochim Biophys Acta Bioenerg 2020 06 12;1861(5-6):148174. Epub 2020 Feb 12.

Protein-Protein Interactions Unit, A.N. Bach Institute of Biochemistry, Federal Research Center of Biotechnology of the Russian Academy of Sciences, 119071 Moscow, Russian Federation; Department of Biophysics, Faculty of Biology, M.V. Lomonosov Moscow State University, 119991 Moscow, Russian Federation. Electronic address:

Photosynthesis requires various photoprotective mechanisms for survival of organisms in high light. In cyanobacteria exposed to high light, the Orange Carotenoid Protein (OCP) is reversibly photoswitched from the orange (OCP) to the red (OCP) form, the latter binds to the antenna (phycobilisomes, PBs) and quenches its overexcitation. OCP accumulation implicates restructuring of a compact dark-adapted OCP state including detachment of the N-terminal extension (NTE) and separation of protein domains, which is reversed by interaction with the Fluorescence Recovery Protein (FRP). Read More

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http://dx.doi.org/10.1016/j.bbabio.2020.148174DOI Listing

Time-resolved FTIR difference spectroscopy for the study of quinones in the A binding site in photosystem I: Identification of neutral state quinone bands.

Biochim Biophys Acta Bioenerg 2020 06 12;1861(5-6):148173. Epub 2020 Feb 12.

Department of Physics and Astronomy, Georgia State University, Atlanta, GA 30303, USA. Electronic address:

Infrared absorption bands associated with the neutral state of quinones in the A binding site in photosystem I (PSI) have been difficult to identify in the past. This problem is addressed here, where time-resolved step-scan FTIR difference spectroscopy at 77 K has been used to study PSI with six different quinones incorporated into the A binding site. (P700A - P700A) and (A - A) FTIR difference spectra (DS) were obtained for PSI with the different quinones incorporated, and several double-difference spectra (DDS) were constructed from the DS. Read More

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http://dx.doi.org/10.1016/j.bbabio.2020.148173DOI Listing