[58] Uncouplers of oxidative phosphorylation

Heytler, Peter G.

doi:10.1016/0076-6879(79)55060-5

Cited by 191 publications

(110 citation statements)

References 37 publications

Supporting

Mentioning

105

Contrasting

Order By: Relevance

“…For FCCP, there was a remarkable correlation between the concentration required to disrupt the mitochondrial membrane potential and the inhibition of chemotaxis. The IC 50 for inhibition of both these functions was ϳ20 nM, in agreement with the known effects of this compound on uncoupling of mitochondrial respiration (35). At higher concentrations of FCCP (Ͼ1 M), the respiratory burst was inhibited, but we believe that this inhibition was due to effects unrelated to uncoupling of mitochondrial function.…”

Section: Discussionsupporting

confidence: 83%

The Mitochondrial Network of Human Neutrophils: Role in Chemotaxis, Phagocytosis, Respiratory Burst Activation, and Commitment to Apoptosis

Fossati

Moulding

Spiller

et al. 2003

The Journal of Immunology

315

251

View full text Add to dashboard Cite

It is commonly assumed that human neutrophils possess few, if any, functional mitochondria and that they do not depend on these organelles for cell function. We have used the fluorescent mitochondrial indicators, JC-1, MitoTracker Red, and dihydrorhodamine 123 to show that live neutrophils possess a complex mitochondrial network that extends through the cytoplasm. The membrane potential of these mitochondria was rapidly (within 2 min) disrupted by the addition of FCCP (IC50 = 20 nM), but not by the Fo-ATPase inhibitor, oligomycin (at up to 7 μg/ml). However, inhibition of mitochondrial function with both agents resulted in cell shape changes. Neither activation of the respiratory burst nor phagocytosis of either latex particles or serum-opsonized Staphylococcus aureus was affected by the addition of FCCP or oligomycin. However, FCCP inhibited chemotaxis at concentrations that paralleled disruption of mitochondrial membrane potential. Furthermore, prolonged (2-h) incubation with oligomycin resulted in an impaired ability to activate a respiratory burst and also inhibited chemotaxis. These observations indicate that intact mitochondrial function is required to sustain some neutrophil functions, but not for the rapid initiation of the respiratory burst or phagocytosis. Loss of mitochondrial membrane potential was a very early marker for commitment of neutrophils into apoptosis and preceded the appearance of phosphatidylserine on the cell surface. However, inhibition of mitochondrial function did not accelerate the rate of neutrophil apoptosis. These data shed important insights into the hitherto unrecognized importance of mitochondria in the function of neutrophils during infection and inflammation.

show abstract

Section: Discussionsupporting

confidence: 83%

The Mitochondrial Network of Human Neutrophils: Role in Chemotaxis, Phagocytosis, Respiratory Burst Activation, and Commitment to Apoptosis

Fossati

Moulding

Spiller

et al. 2003

The Journal of Immunology

315

251

View full text Add to dashboard Cite

show abstract

“…3 Uncouplers can be broadly defined as chemical agents that selectively prevent utilization of chemical energy derived from respiratory electron transport for net phosphorylation of ADP to ATP. 4 Besides acting as uncouplers, ETC inhibitors can also cause mitotoxicity. These substances bind to one or more of the respiratory chain components and block their ability to switch between redox states.…”

Section: Introductionmentioning

confidence: 99%

Measuring Interference of Drug-Like Molecules with the Respiratory Chain: Toward the Early Identification of Mitochondrial Uncouplers in Lead Finding

Stock

Matter

Diekert³

et al. 2013

ASSAY and Drug Development Technologies

View full text Add to dashboard Cite

The electron transport chain (ETC) couples electron transfer between donors and acceptors with proton transport across the inner mitochondrial membrane. The resulting electrochemical proton gradient is used to generate chemical energy in the form of adenosine triphosphate (ATP). Proton transfer is based on the activity of complex I-V proteins in the ETC. The overall electrical activity of these proteins can be measured by proton transfer using Solid Supported Membrane technology. We tested the activity of complexes I, III, and V in a combined assay, called oxidative phosphorylation assay (oxphos assay), by activating each complex with the corresponding substrate. The oxphos assay was used to test in-house substances from different projects and several drugs currently available on the market that have reported effects on mitochondrial functions. The resulting data were compared to the influence of the respective compounds on mitochondria as determined by oxygen consumption and to data generated with an ATP depletion assay. The comparison shows that the oxidative phosphorylation assay provides both a rapid approach for detecting interaction of compounds with respiratory chain proteins and information on their mode of interaction. Therefore, the oxphos assay is a useful tool to support structure activity relationship studies by allowing early identification of mitotoxicity and for analyzing the outcome of phenotypic screens that are susceptible to the generation of mitotoxicity-related artifacts.

show abstract

“…Addition of the protonophore tetrachlorosalicylanilide [31] to CO-metabolizing cells led to an increase in the rate of CO conversion to COz and Hz up to 70%. Concomitantly the ATP level dropped and Ap was abolished (Fig.…”

Section: Ejject Of the Protonophore Tetrachlorosalicylanilide And Of mentioning

confidence: 99%

Coupling of carbon monoxide oxidation to CO2 and H2 with the phosphorylation of ADP in acetate-grown Methanosarcina barkeri

1986

View full text Add to dashboard Cite

Cell suspensions of Methanosarcina barkeri, grown on acetate, catalyzed the conversion of carbon monoxide and H 2 0 to C 0 2 and H2 in stoichiometric amounts when methane formation was inhibited by bromoethanesulfonate. The specific activity was 80-120 nmol min-' mg protein-' at 5% CO in the gas phase. CO oxidation was coupled with the phosphorylation of ADP as indicated by a rapid increase of the intracellular ATP level upon start of the reaction. At least 0.1 mol ATP was formed/mol CO consumed. The onset of CO oxidation was also accompanied by an increase of the proton motive force (Ap) from 100 mV to 150 mV (inside negative). Addition of the uncoupler tetrachlorosalicylanilide to CO-metabolizing cells led to a rapid decrease of the ATP level and of Ap, and to an increase of the CO oxidation rate up to 70%. In the presence of the proton-translocating ATPase inhibitor NJ"'dicyclohexy1carbodiimide the phosphorylation of ADP was inhibited and CO oxidation slowed down, whereas Ap was almost unaffected. Inhibition of CO oxidation under these conditions was relieved by the addition of the protonophore tetrachlorosalicylanilide. The results indicate that in acetate-grown M . barkeri the free-energy change associated with the formation of C 0 2 and H2 from CO and H 2 0 (AG ' = -20 kJ/ mol) can be used to drive the phosphorylation of ADP and that the coupling proceeds via a chemiosmotic mechanism. A possible role of the carbon monoxide oxidation reaction as an energy-conserving site in acetate fermentation to CH4 and C 0 2 is discussed.Methanosarcina barkeri contains an active carbon monoxide dehydrogenase [l], which has been purified and shown to be a nickel iron sulfur protein [2]. In cell extracts of acetategrown cells the specific activity of carbon monoxide dehydrogenase is fivefold higher than in extracts of H2/COz-grown or methanol-grown cells, indicating that the enyzme may play a

show abstract

[58] Uncouplers of oxidative phosphorylation

Cited by 191 publications

References 37 publications

The Mitochondrial Network of Human Neutrophils: Role in Chemotaxis, Phagocytosis, Respiratory Burst Activation, and Commitment to Apoptosis

The Mitochondrial Network of Human Neutrophils: Role in Chemotaxis, Phagocytosis, Respiratory Burst Activation, and Commitment to Apoptosis

Measuring Interference of Drug-Like Molecules with the Respiratory Chain: Toward the Early Identification of Mitochondrial Uncouplers in Lead Finding

Coupling of carbon monoxide oxidation to CO2 and H2 with the phosphorylation of ADP in acetate-grown Methanosarcina barkeri

Contact Info

Product

Resources

About