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Toxicology in Vitro : An International... Sep 2020Oligomycin is a classical mitochondrial reagent that binds to the proton channel on the F component of ATP synthase. As a result, oligomycin blocks mitochondrial ATP...
Oligomycin is a classical mitochondrial reagent that binds to the proton channel on the F component of ATP synthase. As a result, oligomycin blocks mitochondrial ATP synthesis, proton translocation, and O uptake. Here we show that oligomycin induces proton uncoupling subsequent to inhibition of ATP synthesis, as evidenced by recovery of O uptake to near baseline levels. Uncoupling is uniquely rapid and readily observed in HepG2 cells but is also observed at longer times in the unrelated H1299 cell line. Proton fluxes plateau at oligomycin concentrations in the region 0.25-5 μM. At the plateau, fluxes are lower than expected for the classical mitochondrial permeability transition pore, although in H1229 cells, fluxes increase to levels consistent with pore opening at higher oligomycin concentrations. Uncoupling is observed in cells metabolizing either pyruvate or lactate and reversed by addition of glucose to restore ATP synthesis. Uncoupling is not sensitive to cyclosporin A and is not reversed by the ANT inhibitor bongkrekic acid. However, bongkrekic acid inhibits uncoupling if added before oligomycin, which we interpret in terms of maintenance of mitochondrial ATP levels.
Topics: Adenosine Triphosphate; Cell Line; Humans; L-Lactate Dehydrogenase; Mitochondria; Oligomycins; Oxygen; Protons; Uncoupling Agents
PubMed: 32502624
DOI: 10.1016/j.tiv.2020.104907 -
Nature Chemical Biology Jan 2017Small molecules are pharmacological tools of considerable value for dissecting complex biological processes and identifying potential therapeutic interventions.... (Review)
Review
Small molecules are pharmacological tools of considerable value for dissecting complex biological processes and identifying potential therapeutic interventions. Recently, the cellular quality-control process of mitophagy has attracted considerable research interest; however, the limited availability of suitable chemical probes has restricted our understanding of the molecular mechanisms involved. Current approaches to initiate mitophagy include acute dissipation of the mitochondrial membrane potential (ΔΨ) by mitochondrial uncouplers (for example, FCCP/CCCP) and the use of antimycin A and oligomycin to impair respiration. Both approaches impair mitochondrial homeostasis and therefore limit the scope for dissection of subtle, bioenergy-related regulatory phenomena. Recently, novel mitophagy activators acting independently of the respiration collapse have been reported, offering new opportunities to understand the process and potential for therapeutic exploitation. We have summarized the current status of mitophagy modulators and analyzed the available chemical tools, commenting on their advantages, limitations and current applications.
Topics: Antimycin A; Humans; Membrane Potential, Mitochondrial; Mitochondria; Mitophagy; Molecular Structure; Oligomycins
PubMed: 28103219
DOI: 10.1038/nchembio.2287 -
Zhong Nan Da Xue Xue Bao. Yi Xue Ban =... Feb 2021Radiotherapy is one of the main therapies for colorectal cancer, but radioresistance often leads to radiotherapy failure. To improve the radioresistance, we explore the...
OBJECTIVES
Radiotherapy is one of the main therapies for colorectal cancer, but radioresistance often leads to radiotherapy failure. To improve the radioresistance, we explore the effect of oligomycin A, the H-ATP synthase inhibitor, on the sensitivity of HT29 colorectal cancer cells to irradiation and its underlying mechanisms.
METHODS
The effects of different concentrations of oligomycin A on the survival rate and glycolysis of HT29 colorectal cancer cells at different time points were investigated via MTT and glycolysis assay. siRNA-PFK1 was synthesized in vitro and transfected into HT29 cells. The effects of oligomycin A on radiosensitivity of HT29 colorectal cancer cells were measured via MTT and colony formation assay. Western blotting was used to detect the effect of oligomycin A on the expression of glycolytic enzyme PFK1. We compared difference between the effects of siRNA-PFK1 group and oligomycin A combined with siRNA-PFK1 group on cell survival and glycolysis. After 4 Gy X-ray irradiation, the effects of cell survival and glycolysis between the siRNA-PFK1 group and the oligomycin A combined with siRNA-PFK1 group were compared.
RESULTS
Compared with the 0 μmol/L oligomycin A group, the cell survival rate of HT29 cells treated with 4 μmol/L oligomycin A was significantly increased (<0.05), and the glucose uptake, the lactic acid, and the ATP production were also significantly increased (all <0.01). After X-ray irradiation at different doses (0, 2, 4, 6, and 8 Gy), the colony formation rate and cell survival rate of the 4 μmol/L oligomycin A treated group were significantly higher than those in the 0 μmol/L oligomycin A group (both <0.01). The sensitization enhancement ratio of oligomycin A on HT29 colorectal cancer cells was 0.4886. The expression of PFK1 in the 4 μmol/L oligomycin A group was significantly higher than that in the 0 μmol/L oligomycin A group (<0.001). The glycolysis level, colony formation rate, and cell survival rate of the siRNA-PFK1 HT29 cells group were significantly lower than those in the 0 μmol/L oligomycin A group (all <0.05), while the results in the 4 μmol/L oligomycin A combined with siRNA-PFK1 group were significantly higher than those in the siRNA-PFK1 group (all <0.001). After 4 Gy X-ray irradiation, the colony formation rate and cell survival rate in the siRNA-PFK1 group were decreased compared with those in the irradiation group (<0.01 or <0.001), while the results of the 4 μmol/L oligomycin A combined with siRNA-PFK1 group were significantly higher than those in the siRNA-PFK1 group (both <0.001).
CONCLUSIONS
Oligomycin A can promote the radioresistance of HT29 colorectal cancer cells, which may be related to up-regulation of the PFK1 expression and increase of cell glycolysis.
Topics: Cell Line, Tumor; Colorectal Neoplasms; HT29 Cells; Humans; Oligomycins; Radiation Tolerance
PubMed: 33678646
DOI: 10.11817/j.issn.1672-7347.2021.200063 -
Methods in Enzymology 1979
Topics: Adenosine Triphosphatases; Animals; Cattle; Membrane Proteins; Microscopy, Electron; Mitochondria, Heart; Oligomycins; Submitochondrial Particles
PubMed: 156848
DOI: 10.1016/0076-6879(79)55051-4 -
The Journal of Organic Chemistry Jun 2021Oligomycin A is a potent antibiotic and antitumor agent. However, its applications are restricted by its high toxicity and low bioavailability. In this study, we...
Oligomycin A is a potent antibiotic and antitumor agent. However, its applications are restricted by its high toxicity and low bioavailability. In this study, we obtained Oligomycin A Diels-Alder adducts with benzoquinone and -benzylmaleimide and determined their absolute configurations by combining H and ROESY NMR data with molecular mechanics conformational analysis and quantum chemical reaction modeling. The latter showed that adduct stereochemistry is controlled by hydrogen bonding of the Oligomycin A side-chain isopropanol moiety with the carbonyl group of the dienophile. Biological studies showed that the Diels-Alder modification of the Oligomycin A diene system resulted in a complex antiproliferative potential pattern. The synthesized adducts were determined to be more active against the triple-negative (ERα, PR, and HER2 negative) breast cancer cell line MDA-MB-231 and lung carcinoma cell line A-549 compared to Oligomycin A. Meanwhile, Oligomycin A was more potent against myeloid leukemia cell line K-562 and breast carcinoma cell line MCF-7 than its derivatives. Thus, modification of the diene moiety of Oligomycin A is a promising strategy for developing novel antitumor agents based on its scaffold.
Topics: Humans; MCF-7 Cells; Models, Molecular; Molecular Conformation; Oligomycins
PubMed: 34043357
DOI: 10.1021/acs.joc.1c00296 -
Mitochondrion Jul 2013The mitochondrial F₁F₀ complex is highly sensitive to macrolide antibiotics and especially targeted by oligomycins. These compounds bind to the membrane-embedded... (Review)
Review
The mitochondrial F₁F₀ complex is highly sensitive to macrolide antibiotics and especially targeted by oligomycins. These compounds bind to the membrane-embedded sector F₀ and block proton conductance through the inner membrane, thus inhibiting both ATP synthesis and hydrolysis. Oligomycin sensitivity is universally recognized as a clue of the functional integrity and matching between F₀ and F₁. Since oligomycin binding implies multiple interactions with amino acid residues of F₀, amino acid substitutions often affect the inhibition efficiency. Moreover, variegated factors spanning from membrane properties to xenobiotic incorporation and detachment of the oligomycin-insensitive F₁ sector can alter the oligomycin sensitivity of the enzyme complex. The overview on the multiple factors involved strengthens the link between altered oligomycin sensitivity and physiopathological conditions associated with defective ATPases. An improved understanding of the mechanisms involved may also favor drug design to counteract oxidative damage, which stems from most mitochondrial dysfunctions.
Topics: Anti-Bacterial Agents; Enzyme Inhibitors; Mitochondrial Diseases; Oligomycins; Proton-Translocating ATPases
PubMed: 23597783
DOI: 10.1016/j.mito.2013.04.005 -
Methods in Enzymology 1979
Topics: Adenosine Triphosphatases; Kinetics; Macromolecular Substances; Methods; Molecular Weight; Oligomycins; Oxidative Phosphorylation Coupling Factors; Saccharomyces cerevisiae
PubMed: 156843
DOI: 10.1016/0076-6879(79)55044-7 -
The Journal of Protozoology Aug 1982The multiplication rate of "wild-type" (WT) populations of Acanthamoeba castellanii was inhibited 50% by approximately 3 microgram oligomycin/ml; OliR2, an oligomycin...
The multiplication rate of "wild-type" (WT) populations of Acanthamoeba castellanii was inhibited 50% by approximately 3 microgram oligomycin/ml; OliR2, an oligomycin resistant cell line, required approximately 27 microgram/ml for the same inhibition. ATPase solubilized from OliR2 mitochondrial fractions required 3--10-fold higher concentrations of oligomycin than did identical WT fractions to achieve 50% inhibition of activity. Resistance was correlated with altered mitochondrial ATPase sensitivity to oligomycin.
Topics: Adenosine Triphosphatases; Amoeba; Drug Resistance; Mitochondria; Oligomycins
PubMed: 6215480
DOI: 10.1111/j.1550-7408.1982.tb05419.x -
The Journal of Antibiotics Jul 2017Although, the structure of oligomycin A (1) was confirmed by spectroscopic and chemical evaluations, some crystallographic data cast doubt on the originally adopted... (Comparative Study)
Comparative Study
Although, the structure of oligomycin A (1) was confirmed by spectroscopic and chemical evaluations, some crystallographic data cast doubt on the originally adopted structure of the side 2-hydroxypropyl moiety of this antibiotic. It was suggested that the side chain of the oligomycin is enol-related (2-hydroxy-1-propenyl). To clarify this matter we synthesized and evaluated 33-dehydrooligomycin A (2) prepared by the Kornblum oxidation of 33-O-mesyloligomycin A (3) by dimethyl sulfoxide. NMR data for 33-dehydrooligomycin (2) and results of quantum chemical calculations have shown that this derivative exists in the keto rather than in the enol tautomer 2a. The in vitro antimicrobial activity of 2 was approximately two times weaker in comparison with oligomycin A against Streptomyces fradiae ATCC-19609 and reference Candida spp. strains and similar activity against certain filamentous fungi. The docking binding estimate of 2 with FFATP synthase showed a slight decrease in binding affinity for 2 when compared with oligomycin A; that correlated with its activity against S. fradiae ATCC 19609 that is supersensitive to oligomycin A. The in vitro antiproliferative activities of 2 are also discussed.
Topics: Anti-Bacterial Agents; Antifungal Agents; Antineoplastic Agents; Candida; Cell Line, Tumor; Humans; Magnetic Resonance Spectroscopy; Oligomycins; Streptomyces
PubMed: 28420869
DOI: 10.1038/ja.2017.48 -
Natural Product Research Nov 2020We describe the synthesis of epi-oligomycin A, a (33)-diastereomer of the antibiotic oligomycin A. The structure of (33)-oligomycin A was determined by elemental...
We describe the synthesis of epi-oligomycin A, a (33)-diastereomer of the antibiotic oligomycin A. The structure of (33)-oligomycin A was determined by elemental analysis, spectroscopic studies, including 1D and 2D NMR spectroscopy, and mass spectrometry. Isomerization of C33 hydroxyl group led to minor changes in the potency against , , and filamentous fungi whereas the activity against decreased by approximately 20-fold compared to oligomycin A. We observed that 33-epi-oligomycin A had the same activity on the human leukemia cell line K562 as oligomycin A but was more potent for the multidrug resistant subline K562/4. Non-malignant cells were less sensitive to both oligomycin isomers. Finally, our results pointed at the dependence of the cytotoxicity of oligomycins on oxygen supply.
Topics: Animals; Anti-Bacterial Agents; Antibiotics, Antineoplastic; Aspergillus niger; Candida; Cell Proliferation; Dogs; Drug Resistance, Neoplasm; Humans; K562 Cells; MCF-7 Cells; Madin Darby Canine Kidney Cells; Magnetic Resonance Spectroscopy; Mass Spectrometry; Microbial Sensitivity Tests; Oligomycins; Stereoisomerism; Streptomyces; Structure-Activity Relationship
PubMed: 31075992
DOI: 10.1080/14786419.2019.1608540