No data available that match "aurovertins"


Oligomycin, inhibitor of the F0 part of H+-ATP-synthase, suppresses the TNF-induced apoptosis. (1/40)

The release of cytochrome c from the intermembrane space of mitochondria into the cytosol is one of the critical events in apoptotic cell death. In the present study, it is shown that release of cytochrome c and apoptosis induced by tumor necrosis factor alpha (TNF) in HeLa cells can be inhibited by (i) overexpression of an oncoprotein Bcl-2, (ii) Cyclosporin A, an inhibitor of the mitochondrial permeability transition pore (PTP) or (iii) oligomycin, an inhibitor of H+- ATP-synthase. Staurosporine-induced apoptosis is sensitive to Bcl-2 but insensitive to Cyclosporin A and oligomycin. The effect of oligomycin is not due to changes in mitochondrial membrane potential or to inhibition of ATP synthesis/hydrolysis since (a) uncouplers (CCCP, DNP) which discharge the membrane potential fail to abolish the protective action of oligomycin and (b) aurovertin B (another inhibitor of H+-ATP-synthase, affecting its F1 component) do not affect apoptosis. A role of oligomycin-sensitive F0 component of H+-ATP-synthase in the TNF-induced PTP opening and apoptosis is suggested.  (+info)

Influence of aurovertin on mitochondrial ATPase activity. (2/40)

Investigations have been made of the kinetic effects of the antibiotic aurovertin on the ATPase and ITPase activity of isolated rat liver mitochondrial ATPase. Unusual patterns of inhibition, decreasing slope, and increasing y-intercept values of double reciprocal plots, were observed with Mg-ATP as the substrate under various conditions. Under specified conditions, aurovertin stimulated hydrolysis of MgATP. The inhibition of MgITP hydrolysis was uncompetitive. Aurovertin eliminated the HCO3-minus stimulation of MgATP hydrolysis. The implications of these findings for the mechanism of mitochondrial ATPase are briefly discussed.  (+info)

A simple and rapid method for the preparation of adenosine triphosphatase from submitochondrial particles. (3/40)

An almost pure form of the bovine heart mitochondrial adenosine triphosphatase (ATPase) is released from the membrane by shaking submitochondrial particles with chloroform. Analyses on polyacrylamide gels and by electron microscopy, and also sensitivity to inhibitors, show that the chloroform-released enzyme is similar to other ATPase preparations from bovine heart mitochondria.  (+info)

Nucleotide sequence, organization and characterization of the atp genes and the encoded subunits of Mycoplasma gallisepticum ATPase. (4/40)

The nucleotide sequence of a 7.8 kbp DNA fragment from the genome of Mycoplasma gallisepticum has been determined. The fragment contains a cluster of nine tightly linked genes coding for the subunits of the M. gallisepticum ATPase. The gene order is I (I-subunit), B (a-subunit), E (c-subunit), F (b-subunit), H (delta-subunit), A (alpha-subunit), G (gamma-subunit), D (beta-subunit) and C (epsilon-subunit). Two open reading frames were identified in the flanking regions; one (ORFU), preceding the I gene, encodes at least 110 amino acids and the other (ORFS), following the C gene, encodes at least 90 amino acids. The deduced amino acid sequences of the various subunits are presented and discussed with regard to the structure, function and differing sensitivity of the M. gallisepticum enzyme to dicyclohexylcarbodiimide and aurovertin. The alpha- and beta-subunits of the F1 portion are well conserved (51% and 65% identity with those of Escherichia coli), whereas the gamma-, delta- and epsilon-subunits, as well as the F0-subunits, show a low percentage identity. Nonetheless, the secondary structure of the F0-subunits show a high degree of similarity to the corresponding subunits of E. coli. Two very strong potential amphipathic alpha-helices are predicted in the delta-subunit and the N-terminus of the b-subunit contains two hydrophobic helical stretches. The possible roles of these structural properties in the close association of the F1 and F0 multisubunit complexes among mycoplasmas are discussed.  (+info)

Aurovertin binds to the beta subunit of yeast mitochondrial ATPase. (5/40)

Isolated beta subunit of ATPase (F1) from yeast mitochondria does not catalyze an ATPase reaction but still binds the specific F1 inhibitor aurovertin. Binding was measured by enhancement of aurovertin fluorescence; it was as tight as that to F1-ATPase. No binding was observed with F1 or with isolated beta subunit from a single-gene nuclear yeast mutant whose F1-ATPase was resistant to aurovertin.  (+info)

Citreoviridin, a specific inhibitor of the mitochondiral adenosine triphosphatase. (6/40)

1. Citreoviridin was a potent inhibitor of the soluble mitochondrial ATPase (adenosine triphosphatase) similar to the closely related aurovertins B and D. 2. Citreoviridin inhibited the following mitochondrial energy-linked reactions also: ADP-stimulated respiration in whole mitochondria from ox heart and rat liver; ATP-driven reduction of NAD+ by succinate; ATP-driven NAD transhydrogenase and ATPase from ox heart submitochondrial particles. 3. The dissociation constant (KD) calculated by a simple law-of-mass-action treatment for the citreoviridin--ATPase complex was 0.5--4.2micron for ox-heart mitochondrial preparations and 0.15micron for rat liver mitochondria. 4. Monoacetylation of citreoviridin decreased its inhibitory potency (KD=2--25micron, ox heart; KD=0.7micron, rat liver). Diacetylation greatly decreased the inhibitory potency (KD=60--215micron, ox heart). 5. Hydrogenation of citreoviridin monoacetate diminished its inhibitory potency considerably. 6. No significant enhancement of fluorescence was observed when citreoviridin interacted with the mitochondrial ATPase.  (+info)

Isolation of Escherichia coli mutants with an adenosine triphosphatase insensitive to aurovertin. (7/40)

Energy-transducing adenosine triphosphatase (ATPase) from Escherichia coli is inhibited by aurovertin. Aurovertin-resistant mutants were generated by nitrosoguanidine mutagenesis of E. coli AN180, whose growth on a nonfermentable carbon source was blocked by aurovertin. The ATPase activity of cell extracts from 15 different mutants (designated MA1, MA2, MA3, etc.) was found to be at least 20 times less sensitive to aurovertin than that from the parent strain. The aurovertin-resistant mutants did not show cross-resistance towards a number of ATPase inhibitors including azide, dicyclohexylcarbodiimide, quercetin, 7-chloro-4-nitrobenzofurazan, and N-ethoxycarbonyl-2-ethoxy-1,2-dihydroquinoline. Aurovertin inhibited the energization brought about by addition of ATP to E. coli AN180 membrane vesicles; it was without effect on MA1 and MA2 membrane vesicles energized by ATP. The mutation in MA1, like other mutations of the ATPase complex, maps in the unc region of the bacterial chromosome.  (+info)

Inhibition of mitochondrial bioenergetics: the effects on structure of mitochondria in the cell and on apoptosis. (8/40)

The effects of specific inhibitors of respiratory chain, F(o)F(1)ATP synthase and uncouplers of oxidative phosphorylation on survival of carcinoma HeLa cells and on the structure of mitochondria in the cells were studied. The inhibitors of respiration (piericidin, antimycin, myxothiazol), the F(1)-component of ATP synthase (aurovertin) and uncouplers (DNP, FCCP) did not affect viability of HeLa cells, apoptosis induced by TNF or staurosporin and the anti-apoptotic action of Bcl-2. Apoptosis was induced by combined action of respiratory inhibitors and uncouplers indicating possible pro-apoptotic action of reactive oxygen species (ROS) generated by mitochondria. Short-term incubation of HeLa cells with the mitochondrial inhibitors and 2-deoxyglucose followed by 24-48 h recovery resulted in massive apoptosis. Apoptosis correlated to transient (3-4 h) and limited (60-70%) depletion of ATP. More prolonged or more complete transient ATP depletion induced pronounced necrosis. The inhibitors of respiration and uncouplers caused fragmentation of tubular mitochondria and formation of small round bodies followed by swelling. These transitions were not accompanied with release of cytochrome c into the cytosol and were fully reversible. The combined effect of respiratory inhibitors and uncouplers developed more rapidly indicating possible involvement of ROS generated by mitochondria. More prolonged (48-72 h) incubation with this combination of inhibitors caused clustering and degradation of mitochondria.  (+info)

Citreoviridin contents were measured in eight bulk samples of maize kernels collected from eight fields immediately following harvest in southern Georgia. Citreoviridin contamination in six of the bulk samples ranged from 19 to 2,790 micrograms/kg. In hand-picked samples the toxin was concentrated in a few kernels (pick-outs), the contents of which were stained a bright lemon yellow (range, 53,800 to 759,900 micrograms/kg). The citreoviridin-producing fungus Eupenicillium ochrosalmoneum Scott & Stolk was isolated from each of these pick-out kernels. Citreoviridin was not detected in bulk samples from two of the fields. Aflatoxins were also present in all of the bulk samples (total aflatoxin B1 and B2; range, 7 to 360 micrograms/kg), including those not containing citreoviridin. In Biotron-grown maize ears that were inoculated with E. ochrosalmoneum through a wound made with a toothpick, citreoviridin was concentrated primarily in the wounded and fungus-rotted kernels (range, 142,000 to 2,780,000
In the past decade, ectopic ATP synthase has been shown to involve a variety of functions in lipid metabolism, immune recognition, and invasiveness of tumors (3, 6, 9, 16), regulation of intracellular pH (14, 30), differentiation (13), control of proliferation and cell death (3, 10, 15). Ectopic ATP synthase has been shown to localize on the cell membrane of different cancer cell types. Here, we show that the ATP synthase complex and ETC are localized on the membrane of lung cancer cells. In an attempt to shed light on the cellular processes affected by the action of this complex, and to provide further insights into the mechanistic action of the ATP synthase inhibitor citreoviridin, we show that the inhibition of ectopic ATP synthase is associated with the inhibition of lung cancer cell growth and the activation of UPR. By disrupting the homeostasis of the ER, citreoviridin could specifically target ectopic ATP synthase-expressing cancer cells and effectively inhibit growth with limited side ...
Aspergillus alabamensis is a soil fungus in the division Ascomycota first described in 2009 as a segregated taxon of A. terreus. Originally thought to be a variant of A. terreus, A. alabamensis is situated in a distinctive clade identified by genetic analysis. While A. alabamensis has been found to be morphologically similar to Aspergillus terreus by morphological studies, the two differ significantly in active metabolic pathways with A. alabamensis producing the mycotoxin citrinin and citreoviridin but lacking mevinolin. Aspergillus alabamensis was discovered by Balajee and colleagues in 2009 while investigating the cryptic lineages in A. terreus in a multilocus sequence typing (MLST) study of three protein-encoding genes: enolase (enoA) β-tubulin (benA) and calmodulin (calM). They chose the species epithet "alabamensis" to reflect their geographic origin of strains comprising the new clade with 11 of the 14 isolates originating from clinical specimens obtained from the University of Alabama ...
Learn more about 4-chloro-7-nitrobenzofurazan. We enable science by offering product choice, services, process excellence and our people make it happen.
1. We used 11 different inhibitors of energy conservation as inhibitors of ATPase (adenosine triphosphatase) in extracts of Schizosaccharomyces pombe obtained from cells at different stages of the cell cycle. 2. All the inhibitors showed cell-cycle-dependent variations in their I50 values (microng of inhibitor/mg of protein giving 50% inhibition of inhibitor-sensitive ATPase at pH 8.6). 3. From the sensitivity profiles through the cell cycle it was concluded that: (a) oligomycin, venturicidin, triethyltin sulphate and dibutylchloromethyltin chloride all act at closely associated site(s); (b) NN-dicyclohexylcarbodi-imide and leucinostatin both act at a similar site, which is, however, distinct from that at which other inhibitors of the membrane factor (Fo) act. 4. The variations in I50 values for efrapeptin closely followed changes in specific activity of ATPase, as would be expected for an inhibitor acting at catalytic sites; these fluctuations were different from those for aurovertin, Dio-9, ...
ATP synthase, H+ transporting, mitochondrial F0 complex, subunit c3 (subunit 9) genome duplicate b [Source:ZFIN;Acc:ZDB-GENE-020814-1 ...
Shop ATP synthase mitochondrial F1 complex assembly factor ELISA Kit, Recombinant Protein and ATP synthase mitochondrial F1 complex assembly factor Antibody at MyBioSource. Custom ELISA Kit, Recombinant Protein and Antibody are available.
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... aurovertins MeSH D03.383.663.491 --- iridoids MeSH D03.383.663.620 --- nigericin MeSH D03.383.663.705 --- pyran copolymer MeSH ...
Aurovertins belong to a family of highly reducing polyketides sharing a polyene α-pyrone-type structure. These compounds ... Guo H, Feng T, Li Z-H, Liu J-K (2013) Ten new aurovertins from cultures of the basidiomycete Albatrellus confluens. Nat Prod ... Aurovertins belong to a family of highly reducing polyketides sharing a polyene α-pyrone-type structure. These compounds ... Wang YL, Li LF, Li DX, Wang B, Zhang K, Niu X (2015b) Yellow pigment aurovertins mediate interactions between the pathogenic ...
2008). Aurovertins F−H from the entomopathogenic fungus Metarhizium anisopliae. Journal of Natural Products, 71, 278-280. ... 2015). Yellow pigment aurovertins mediate interactions between the pathogenic fungus Pochonia chlamydosporia and its nematode ...
Aurovertins are fungal polyketides that exhibit potent inhibition of adenosine triphosphate synthase. Aurovertins contain a 2,6 ...
... aurovertins MeSH D03.383.663.491 --- iridoids MeSH D03.383.663.620 --- nigericin MeSH D03.383.663.705 --- pyran copolymer MeSH ...
Aurovertins are fungal polyketides that display potent inhibition of ATP synthase.. Aurovertins are fungal polyketides that ... to produce aurovertins and gathered 7 (Amount 3 we and ii). No desmethyl variations of aurovertins could possibly be discovered ... Number 4 The tasks of AurC and AurD in biosynthesis of aurovertins. Traces i and ii are components from candida both UV and ... cluster was also found in another maker of aurovertins 5 and in in (Number S2) led to total abolishment of aurovertin ...
Aurovertins ‎ (← links). *Disintegrin ‎ (← links). *Elective culture ‎ (← links). *Anti-infective agents ‎ (← links). *Bowman- ...
Aurovertins D3.830.75 Australia Z1.338 Australian Capital Territory Z1.338.240 Z1.639.100.500 Z1.678.100.373.500 Autistic ...
Thomas AA, Hunt KW, Volgraf M, Watts RJ, Liu X, Vigers G, Smith D, Sammond D, Tang TP, Rhodes SP, Metcalf AT, Brown KD, Otten JN, Burkard M, Cox AA, Do MK, Dutcher D, Rana S, DeLisle RK, Regal K, Wright AD, Groneberg R, Scearce-Levie K, Siu M, Purkey HE, Lyssikatos JP, Gunawardana IW. Discovery of 7-tetrahydropyran-2-yl chromans: ß-site amyloid precursor protein cleaving enzyme 1 (BACE1) inhibitors that reduce amyloid ß-protein (Aß) in the central nervous system. J Med Chem. 2014 Feb 13; 57(3):878-902 ...
Antimetabolites, Antineoplastic/*pharmacology; Aurovertins/pharmacology; Cell Line, Tumor; Cell Proliferation/drug effects; ...
Mao, X. M., Zhan, Z. J., Grayson, M. N., Tang, M. C., Xu, W., Li, Y. Q., Yin, W. B., Lin, H. C., Chooi, Y. H., Houk, K. N. & Tang, Y., 23 Sep 2015, In : Journal of the American Chemical Society. 137, 37, p. 11904-11907 4 p.. Research output: Contribution to journal › Article ...

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