Abstract：
:The unique bifurcated oxidation of ubiquinol at center P (Qo) of the cytochrome bc1 complex is the reaction within the Q-cycle reaction scheme that is most critical for the link between electron transfer and vectorial proton translocation. While there is a general consensus about the overall reaction at center P, the nature of the intermediates and the way the reaction is controlled to ensure obligatory bifurcation is still controversial. By reducing the reaction to its essential steps, a kinetic net rate model is developed in which the activation barrier is associated with the deprotonation of ubiquinol, but the steady state rate is kinetically controlled by the occupancy of the ubiquinol anion and the semiquinone state. This concept is used to interpret experimental data and is discussed in terms of various mechanistic models that are under discussion. It is outlined how other aspects of the center P mechanism like the proposed "prosthetic" ubiquinone and the moving domain of the "Rieske" protein could be incorporated in the kinetic framework.
journal_name
J Bioenerg Biomembrjournal_title
Journal of bioenergetics and biomembranesauthors
Brandt Udoi
10.1023/a:1005471829569keywords:
subject
Has Abstractpub_date
1999-06-01 00:00:00pages
243-50issue
3eissn
0145-479Xissn
1573-6881journal_volume
31pub_type
杂志文章abstract：:Calcium may function directly in several aspects of photosynthesis. It appears to modulate activity of the phosphatase enzymes in the carbon reduction cycle and also to regulate chloroplast NAD+ kinase activity through a calmodulin-like protein. Some evidence supports a calcium function in the water-splitting complex,...
journal_title：Journal of bioenergetics and biomembranes
pub_type： 杂志文章,评审
doi：10.1007/BF00744278
更新日期：1984-08-01 00:00:00
abstract：:Traditionally, mitochondria have been viewed as the "powerhouse" of the cell, i.e., the site of the oxidative phosphorylation machinery involved in ATP production. Consequently, much of the research conducted on mitochondria over the past 4 decades has focused on elucidating both those molecular events involved in ATP...
journal_title：Journal of bioenergetics and biomembranes
pub_type： 杂志文章,评审
doi：10.1023/a:1005453700533
更新日期：1999-08-01 00:00:00
abstract：:The role of the adenine nucleotide translocase on Ca2+ homeostasis in mitochondria from brown adipose tissue was examined. It was found that in mitochondria incubated with 50 microM Ca2+, ADP was not needed to retain the cation, but it was required for strengthening the inhibitory effect of cyclosporin on membrane per...
journal_title：Journal of bioenergetics and biomembranes
pub_type： 杂志文章
doi：
更新日期：1996-02-01 00:00:00
abstract：:Proton transport-coupled unisite catalysis was measured with the H(+)-ATPase from chloroplasts. The reaction was measured in the ATP hydrolysis direction under deenergized conditions and in the ATP synthesis direction under energized conditions. The equilibrium constant of the enzyme does not change upon energization,...
journal_title：Journal of bioenergetics and biomembranes
pub_type： 杂志文章,评审
doi：10.1007/BF00762367
更新日期：1992-10-01 00:00:00
abstract：:Renal artery clamping itself induces renal ischemia which subsequently causes renal cell injury and can lead to renal failure. The duration of warm ischemia that would be safe for postoperative kidney function during partial nephrectomy remains under investigations. Mitochondria play an important role in pathophysiolo...
journal_title：Journal of bioenergetics and biomembranes
pub_type： 杂志文章
doi：10.1007/s10863-016-9643-2
更新日期：2016-02-01 00:00:00
abstract：:ATP1-111, a suppressor of the slow-growth phenotype of yme1Delta lacking mitochondrial DNA is due to the substitution of phenylalanine for valine at position 111 of the alpha-subunit of mitochondrial ATP synthase (Atp1p in yeast). The suppressing activity of ATP1-111 requires intact beta (Atp2p) and gamma (Atp3p) subu...
journal_title：Journal of bioenergetics and biomembranes
pub_type： 杂志文章
doi：10.1007/s10863-007-9071-4
更新日期：2007-04-01 00:00:00
abstract：:Bacterial growth at the extremes of temperature has remained a fascinating aspect in the study of membrane function and structure. The stability of the integral membrane proteins of thermophiles make them particularly amenable to study. Respiratory enzymes of thermophiles appear to be functionally similar to the mesop...
journal_title：Journal of bioenergetics and biomembranes
pub_type： 杂志文章,评审
doi：10.1007/BF00762352
更新日期：1992-12-01 00:00:00
abstract：:Cytoplasmic organelles with an acidic luminal pH include vacuoles, coated vesicles, lysosomes, the Golgi apparatus, and synaptic vesicles. Acidic compartments are also known outside specialized cells such as osteoclasts. The unique acidic pH is formed by V-ATPase (Vacuolar type ATPase), other ion transporters, and the...
journal_title：Journal of bioenergetics and biomembranes
pub_type： 杂志文章,评审
doi：10.1023/a:1025780932403
更新日期：2003-08-01 00:00:00
abstract：:By manipulating the physical properties of oxygen, cells are able to harvest the large thermodynamic potential of oxidation to provide a substantial fraction of the energy necessary for cellular processes. The enzyme largely responsible for this oxygen manipulation is cytochrome c oxidase, which resides at the inner m...
journal_title：Journal of bioenergetics and biomembranes
pub_type： 杂志文章,评审
doi：10.1007/s10863-007-9084-z
更新日期：2007-06-01 00:00:00
abstract：:Free radical production and leak of brain nonsynaptic mitochondria were higher with pyruvate/malate than with succinate in rats and pigeons. Rotenone, antimycin A, and myxothiazol maximally stimulated free radical production with pyruvate/malate but not with succinate. Simultaneous treatment with myxothiazol plus anti...
journal_title：Journal of bioenergetics and biomembranes
pub_type： 杂志文章
doi：10.1023/a:1020592719405
更新日期：1998-06-01 00:00:00
abstract：:We have studied the effect of general anesthetics on the mobility of two stearic acid spin labels (5-doxyl stearic acid and 16-doxyl stearic acid) in bovine heart mitochondria and in phospholipid vesicles made from either mitochondrial lipids or commercial soybean phospholipids. The general anesthetics used include no...
journal_title：Journal of bioenergetics and biomembranes
pub_type： 杂志文章
doi：10.1007/BF00743158
更新日期：1979-04-01 00:00:00
abstract：:Copper transporting P-type ATPases, designated ATP7A and ATP7B, play an essential role in mammalian copper balance. Impaired intestinal transport of copper, resulting from mutations in the ATP7A gene, lead to Menkes disease in humans. Defects in a similar gene, the copper transporting ATPase ATP7B, result in Wilson di...
journal_title：Journal of bioenergetics and biomembranes
pub_type： 杂志文章,评审
doi：10.1023/a:1021293818125
更新日期：2002-10-01 00:00:00
abstract：:It is proven that any model of localized protonmotive energy coupling that relies upon properties of a homogeneous surface phase must, when operated in the steady state, lead to bulk phase electrochemical potentials for protons that are as large as those required by the delocalized chemiosmotic theory. To obtain model...
journal_title：Journal of bioenergetics and biomembranes
pub_type： 杂志文章,评审
doi：10.1007/BF00743612
更新日期：1986-02-01 00:00:00
abstract：:Crude membrane preparations of a rho0 mutant of Saccharomyces cerevisiae exhibit Mg2+-dependent ATPase activity. Over the optimal pH range, 5.0-6.75, the apparent Vmax of the enzyme equals 590 nmoles of ATP hydrolyzed per minute per milligram protein, with an apparent Km for ATP of 1.3 mM. ATP hydrolysis is insensitiv...
journal_title：Journal of bioenergetics and biomembranes
pub_type： 杂志文章
doi：10.1007/BF00744687
更新日期：1980-08-01 00:00:00
abstract：:Gramicidin A forms ion-conducting channels which can traverse the hydrocarbon core of lipid bilayer membranes. The structures formed by gramicidin A are among the best characterized of all membrane-bound polypeptides or proteins. In this review a brief summary is given of the occurrence, conformation, and synthesis of...
journal_title：Journal of bioenergetics and biomembranes
pub_type： 杂志文章,评审
doi：10.1007/BF00762301
更新日期：1987-12-01 00:00:00
abstract：:We have studied a mutant strain of Drosophila in which 80% of the mitochondrial DNA molecules have lost over 30% of their coding region through deletion. This deletion affects genes encoding five subunits of complex I of the respiratory chain (NADH:ubiquinone oxidoreductase). The enzymatic activity of complex I in the...
journal_title：Journal of bioenergetics and biomembranes
pub_type： 杂志文章
doi：10.1023/b:jobb.0000023624.06665.40
更新日期：2004-04-01 00:00:00
abstract：:In the present study we have observed a higher state of coupling in respiring mitochondria isolated from green as compared to red tomatoes (Lycopersicon esculentum, Mill.). Green tomato mitochondria produced a membrane potential (deltapsi) high enough to phosphorylate ADP, whereas in red tomato mitochondria, BSA and A...
journal_title：Journal of bioenergetics and biomembranes
pub_type： 杂志文章
doi：10.1023/a:1005408809619
更新日期：1999-10-01 00:00:00
abstract：:Cytochrome c oxidase was purified from mitochondria of Euglena gracilis and separated into 15 different polypeptide subunits by polyacrylamide gel electrophoresis. All 15 subunits copurify through various purification procedures, and the subunit composition of the isolated enzyme is identical to that of the immunoprec...
journal_title：Journal of bioenergetics and biomembranes
pub_type： 杂志文章
doi：10.1007/BF00762727
更新日期：1989-06-01 00:00:00
abstract：:Caloric restriction (CR) is widely known to increase life span and resistance to different types of injuries in several organisms. We have previously shown that mitochondria from livers or brains of CR animals exhibit higher calcium uptake rates and lower sensitivity to calcium-induced mitochondrial permeability trans...
journal_title：Journal of bioenergetics and biomembranes
pub_type： 杂志文章
doi：10.1007/s10863-020-09838-4
更新日期：2020-08-01 00:00:00
abstract：:Subunit II of cytochrome c oxidase (Cox2) is usually encoded in the mitochondrial genome, synthesized in the organelle, inserted co-translationally into the inner mitochondrial membrane, and assembled into the respiratory complex. In chlorophycean algae however, the cox2 gene was split into the cox2a and cox2b genes, ...
journal_title：Journal of bioenergetics and biomembranes
pub_type： 杂志文章
doi：10.1007/s10863-017-9728-6
更新日期：2017-12-01 00:00:00
abstract：:Retinoic acid inhibits the reduction of diferric transferrin through the transplasma membrane electron transport system on fetal rat liver cells infected with a temperature-sensitive SV40 virus when the cells are in the nontransformed state cultured at 40 degrees C. When the cells are in the transformed state (grown a...
journal_title：Journal of bioenergetics and biomembranes
pub_type： 杂志文章
doi：10.1007/BF00769639
更新日期：1988-06-01 00:00:00
abstract：:Absorbance changes at 446 nm in purified cytochrome oxidase following flash photolysis of carboxy-oxidase poised in the mixed valance state at +220 mV show biphasic kinetics. One phase corresponds to CO recombination to ferrous cytochrome a3 with an energy of activation of 9 kcal/mol; the second phase is 3-5 times fas...
journal_title：Journal of bioenergetics and biomembranes
pub_type： 杂志文章
doi：10.1007/BF00762550
更新日期：1988-12-01 00:00:00
abstract：:Since the nineteenth century, a great amount of different biological structures and processes have been assessed by fluorescent dyes. Along with the uses of these compounds as vital and histological dyes, some fluorescent dyes have become valuable tools for the study of the pore phenomenon in plasma membranes. Some io...
journal_title：Journal of bioenergetics and biomembranes
pub_type： 杂志文章
doi：10.1007/s10863-015-9613-0
更新日期：2015-08-01 00:00:00
abstract：:Liver mitochondria isolated from rats 24 h after a single subcutaneous injection of 8 mg thyroxine per kilogram body weight were compared with those isolated from control rats that received injections of isotonic saline at the same time. The mitochondria isolated from the thyroxine-treated rats show higher rates of en...
journal_title：Journal of bioenergetics and biomembranes
pub_type： 杂志文章
doi：10.1007/BF00748766
更新日期：1980-12-01 00:00:00
abstract：:One of the challenging features of energy-transducing terminal oxidases, like the aa3 cytochrome c oxidase of Paracoccus denitrificans, is the translocation of protons across the cytoplasmic membrane, which is coupled to the transfer of electrons to oxygen. As a prerequisite for a more advanced examination of the enzy...
journal_title：Journal of bioenergetics and biomembranes
pub_type： 杂志文章,评审
doi：10.1023/a:1020515713103
更新日期：1998-02-01 00:00:00
abstract：:The presence of additional subunits in cytochrome oxidase distinguish the multicellular eukaryotic enzyme from that of a simple unicellular bacterial enzyme. The number of these additional subunits increases with increasing evolutionary stage of the organism. Subunits I-III of the eukaryotic enzyme are related to the ...
journal_title：Journal of bioenergetics and biomembranes
pub_type： 杂志文章,评审
doi：10.1007/BF00762225
更新日期：1991-04-01 00:00:00
abstract：:Both cellular proliferation and apoptosis (programmed cell death) have been claimed to be modulated, perhaps even triggered by, changes in intracellular pH. In this review, we summarize the evidence that gave rise to these hypotheses. To facilitate a critical appraisal of the existing data, we briefly review the main ...
journal_title：Journal of bioenergetics and biomembranes
pub_type： 杂志文章,评审
doi：10.1023/a:1022407116339
更新日期：1997-08-01 00:00:00
abstract：:The presence of transplasma membrane electron transport in a variety of plant cells and tissues is reported. It is now agreed that this property of eukaryotic cells is of ubiquitous nature. Studies with highly purified plasma membranes have established the presence of electron transport enzymes. Two types of activitie...
journal_title：Journal of bioenergetics and biomembranes
pub_type： 杂志文章,评审
doi：10.1007/BF00771013
更新日期：1991-06-01 00:00:00
abstract：:Complete initial steady state kinetics of NADH-decylubiquinone (DQ) oxidoreductase reaction between pH 6.5 and 9.0 show an ordered sequential mechanism in which the order of substrate bindings and product releases is NADH-DQ-DQH2-NAD+. NADH binding to the free enzyme is accelerated by protonation of an amino acid (pos...
journal_title：Journal of bioenergetics and biomembranes
pub_type： 杂志文章
doi：10.1023/a:1027387730474
更新日期：2003-10-01 00:00:00
abstract：:Transformation of 3T3 cells by SV40 virus changes the properties of the transplasma membrane electron transport activity which can be assayed by reduction of external ferric salts. After 42 h of culture and before the growth rate is maximum, the transformed cells have a much slower rate of ferric reduction. The change...
journal_title：Journal of bioenergetics and biomembranes
pub_type： 杂志文章
doi：10.1007/BF00786008
更新日期：1991-12-01 00:00:00
