Where results make sense

About us   |   Why use us?   |   Reviews   |   PR   |   Contact us

Aconitase structure Lauble, H., Kennedy, M.C., Beinert, H. and Stout, C.D. Crystal structures of aconitase with isocitrate and nitroisocitrate bound. Robbins, A.H. and Stout, C.D. Structure of activated aconitase: formation of the [4Fe-4S] cluster in the crystal. Robbins, A.H. and Stout, C.D. Iron-sulfur cluster in aconitase. metallo.scripps.edu /PROMISE/7ACN.html   (198 words)

Shery Varghese 2003 221 Expression of the plasmid-encoded aconitases was induced by the addition of 1 mM IPTG either for 4 h at 25°C (aconitase A) or for 2 h at 37°C (aconitase B) (47). Similarly, the aconitase isolated by Hausladen and Fridovich for measurements of superoxide sensitivity was presumably AcnA, as indicated by its resistance to EDTA (26). Biochemical and spectroscopic characterization of Escherichia coli aconitases (AcnA and AcnB). www.bionewsonline.com /x/3/shery_varghese_2003_221.htm   (7443 words)

Greg A. Somerville 2002 1430 Inasmuch as aconitase is a bifunctional protein with an enzymatic and regulatory function (1, 30) and has been postulated to be a virulence factor regulator (29), we also examined the effect of serial passage on growth and virulence factor production. Aconitase has been shown to have both an enzymatic and regulatory function (1, 30) and has been postulated to be involved in virulence factor regulation (29). Aconitase activity (i.e., the conversion of citrate to isocitrate) is mediated by an essential redox inactive iron-sulfur center. www.bionewsonline.com /i/p/greg_a_somerville_2002_1430.htm   (4881 words)

Researchers at UT Southwestern discover new function for old enzyme To determine the region of aconitase that keeps mitochondrial DNA intact, Dr. Butow's group made mutations in parts of the enzyme that are important for its catalytic activity. Genes in the cell's nucleus code for aconitase, and once made, the protein is shuttled to the mitochondria to serve its functions. The role of aconitase in stabilizing the mitochondrial genome may be an evolutionary adaptation where the mitochondria co-opts a nuclearly encoded protein to ensure survival of its genome, said Dr. Butow. www.eurekalert.org /pub_releases/2005-02/uots-rau020205.php   (651 words)

Aconitase By contrast with the majority of iron-sulphur proteins that function as electron carriers, the Fe-S cluster of aconitase reacts directly with an enzyme substrate [1, 2]. Aconitase (complex with sulphate) (minor occupancy form); bovine heart Lauble, H., Kennedy, M.C., Beinert, H. and Stout, C.D. Crystal structures of aconitase with trans­aconitate and nitrocitrate bound. metallo.scripps.edu /promise/ACONITASE.html   (544 words)

Peroxynitrite Increases the Degradation of Aconitase and Other Cellular Proteins by Proteasome -- Grune et al. 273 ... Aconitase was labeled by reductive methylation as described by Jentoft and Dearborn (44). increased the susceptibility of aconitase to degradation by the proteasome is responsible for the degradation of oxidized aconitase. www.jbc.org /cgi/content/full/273/18/10857   (4962 words)

Aconitase Aconitase enzyme activity depends of the presence of a [4Fe-4S] cluster (3). The assembly and disassembly of the [4Fe-4S] cluster does not depend on the aconitase mechanism, and the mitochondrial protein is present to function in the TCA cycle, so it is unclear why the cytosolic protein retains its enzymatic acitivity (5). One suggestion is that it is important for aconitase function to be regulated by iron, perhaps because citrate is involved in iron transport throughout the cell (5). www.arches.uga.edu /~smc/bcmb8010   (529 words)

Subcellular localization of Pseudomonas pyocyanin cytotoxicity in human lung epithelial cells -- O'Malley et al. 284 ... Cellular aconitase activity was determined for whole cell lysates (B) or for cytosolic- and mitochondrial-containing fractions (C) and revealed a concentration-dependent decrease in aconitase for total, cytosolic, and mitochondrial aconitase activity. The absence of an antibody to cytosolic aconitase Total cellular aconitase activity of control and pyocyanin-treated (10 and 20 µM) A549 cells was determined at 4, 8, and 24 h of pyocyanin exposure. ajplung.physiology.org /cgi/content/full/284/2/L420   (6273 words)

A Developmentally Regulated Aconitase Related to Iron-regulatory Protein-1 Is Localized in the Cytoplasm and in the ... Aconitase (citrate(isocitrate) hydro-lyase, EC 4.2.1.3) catalyzes the stereospecific dehydration/rehydration reaction of The presequence of porcine mitochondrial aconitase was not included, and manual adjustments of the alignment were made at the N terminus. aconitase purified from cytosol and mitochondria is indistinguishable www.jbc.org /cgi/content/full/275/4/2745   (7270 words)

A novel eukaryotic factor for cytosolic Fe-S cluster assembly -- Roy et al. 22 (18): 4826 -- The EMBO Journal   (Site not responding. Last check: 2007-10-13) Aconitase assays were performed as described in the legend to Figure 2A using extracts from logarithmically growing AR27/IRP1 transformed with the indicated CFD1 genes. Kennedy,M.C., Emptage,M.H., Dreyer,J.L. and Beinert,H. (1983) The role of iron in the activation–inactivation of aconitase. Kennedy,M.C., Mende-Mueller,L., Blondin,G.A. and Beinert,H. (1992) Purification and characterization of cytosolic aconitase from beef liver and its relationship to the iron-responsive element binding protein. embojournal.npgjournals.com /cgi/content/full/22/18/4826   (6159 words)

Nitric Oxide Modulates the Activity of Tobacco Aconitase -- Navarre et al. 122 (2): 573 -- PLANT PHYSIOLOGY of buffer A and assayed for aconitase and fumarase Partially purified aconitase from tobacco leaves, prepared as described in Table I, was used for aconitase assays. Kennedy MC, Emptage MH, Dreyer JL, Beinert H (1983) The role of iron in the activation-inactivation of aconitase. www.plantphysiol.org /cgi/content/full/122/2/573   (5915 words)

Mitochondrial complex I, aconitase, and succinate dehydrogenase during hypoxia-reoxygenation: modulation of enzyme ... Total aconitase activity in the air control cells averaged 29.6 ± 5.6 milliunits/mg protein. Aconitase and SDH are also prone to ROS attack and inactivation. Aconitase is a sensitive and critical target of oxygen poisoning in cultured mammalian cells and in rat lungs. ajplung.physiology.org /cgi/content/full/285/1/L189   (5507 words)

Inactivation of Both RNA Binding and Aconitase Activities of Iron Regulatory Protein-1 by Quinone-induced Oxidative ... Menadione-induced Inactivation of the Cytoplasmic Aconitase Activity of IRP-1-- In iron-replete cells, IRP-1 acquires enzymatic activity as a cytoplasmic aconitase at the expense of IRE binding. The percentage of remaining aconitase activity is plotted against the various treatments. The presence or absence of the 4Fe-4S cluster is a critical determinant for the function of IRP-1 as an aconitase or as an www.jbc.org /cgi/content/full/274/10/6219   (4611 words)

Oxidative damage during aging targets mitochondrial aconitase.   (Site not responding. Last check: 2007-10-13) Utilizing an immunochemical probe for oxidatively modified proteins, we show that mitochondrial aconitase, an enzyme in the citric acid cycle, is a specific target during aging of the housefly. The oxidative damage detected immunochemically was paralleled by a loss of catalytic activity of aconitase, an enzyme activity that is critical in energy metabolism. The identification of a specific target of oxidative damage during aging allows for the assessment of the physiological age of a specific individual and provides a method for the evaluation of treatments designed to affect the aging process. www.arclab.org /medlineupdates/abstract_9326580.html   (193 words)

From bacteria to mitochondria: Aconitase yields surprises -- Walden 99 (7): 4138 -- Proceedings of the National Academy ... Aconitase is an interesting enzyme to consider in the evolution of metabolic pathways. Baughn and Malamy (3), the aconitase of R. Aconitase was one of the first enzymes for www.pnas.org /cgi/content/full/99/7/4138   (1877 words)

Changes in the mitochondrial proteome from mouse hearts deficient in creatine kinase -- KERNEC et al. 6 (2): 117 -- ... of precursor aconitase from mitochondria to the cytosol. The upper series of aconitase spots contains the following peptides: 1,519.73 (expected: 1,519.87) which corresponds to the peptide from position 1–13; and 884.59 (expected: 884.57), which corresponds to the peptide from 11–18. of aconitase is known to be localized mainly in the mitochondria. physiolgenomics.physiology.org /cgi/content/full/6/2/117   (5497 words)

The Phosphinomethylmalate Isomerase Gene pmi, Encoding an Aconitase-Like Enzyme, Is Involved in the Synthesis of ... The standard aconitase activity was assayed spectroscopically at 240 nm after the conversion of citrate to isocitrate. The dendrogram was generated by the program TreeView (23) using a multiple alignment of aconitases, isopropylmalate isomerases (IPMI), homoaconitases, and IRP deposited in GenBank and SwissProt (according to reference 13). Inactivation of the TCA cycle aconitase gene from Streptomyces viridochromogenes Tü494 impairs the morphological and physiological differentiation. aem.asm.org /cgi/content/full/67/8/3603   (3540 words)

The secondary alcohol metabolite of doxorubicin irreversibly inactivates aconitase/iron regulatory protein-1 in ... Aconitase and IRP-1 activities in unmodified, iron-loaded, and iron-depleted cytosols. of cis-aconitate as a substrate intermediate of aconitase. In the absence of fluorocitrate, aconitase activity was 2.4 mU/mg protein, whereas 4-demethyl deoxy-DOXol aglycone, DOX, and low mol wt Fe(II) were 1.6, 1.8, and 3.4 nmol/mg protein, respectively. www.fasebj.org /cgi/content/full/12/7/541   (6250 words)

AcnC of Escherichia coli is a 2-methylcitrate dehydratase (PrpD) that can use citrate and isocitrate as substrates -- ... aconitase activity was associated with the enriched fractions. Horswill, A. and Escalante-Semerena, J. In vitro conversion of propionate to pyruvate by Salmonella enterica enzymes: 2-methylcitrate dehydratase (PrpD) and aconitase enzymes catalyse the conversion of 2-methylcitrate to 2-methylisocitrate. Oxidation of propionate to pyruvate in Escherichia coli: Involvement of methylcitrate dehydratase and aconitase mic.sgmjournals.org /cgi/content/full/148/1/133   (6003 words)

In Vitro Serial Passage of Staphylococcus aureus: Changes in Physiology, Virulence Factor Production, and agr ... Aconitase (citrate [isocitrate] hydrolyase, EC 4.2.1.3) is a Aconitase is a citric acid cycle enzyme that converts citrate Aconitase activity (i.e., the conversion of citrate to isocitrate) jb.asm.org /cgi/content/full/184/5/1430   (4498 words)

Irreversible Inhibition of Metabolic Function and Islet Destruction after a 36-Hour Exposure to Interleukin-1{beta} -- ... previously (6), and aconitase was assayed at 340 nm in a reaction The cells were isolated, and mitochondrial aconitase activity was measured as described in Materials and Methods. Control islets were incubated in the absence of cytokines or NMMA for the entire length of the experiments (18-h cytokine incubation + 8-h NMMA recovery for a total of 26 h). endo.endojournals.org /cgi/content/full/138/12/5301   (5051 words)

From the Cover: A mitochondrial-like aconitase in the bacterium Bacteroides fragilis: Implications for the evolution of ... A mitochondrial-like aconitase in the bacterium Bacteroides fragilis: Implications for the evolution of the mitochondrial Krebs cycle The aconitase locus of ADB237 is predicted to encode the amino-terminal 394 residues of the B. To determine whether the presence of aconitase is necessary for IDH activity, strain ADB245 was constructed by allelic exchange. www.pnas.org /cgi/content/full/99/7/4662   (4176 words)

OXIS Aconitase   (Site not responding. Last check: 2007-10-13) According to recent literature, decreased aconitase enzyme activity is a sensitive and specific indicator of oxidative damage during aging, Parkinson's and other disease progression. The function of aconitase is to isomerize citrate to isocitrate a key intermediate of the citric acid cycle. The holo (4Fe/ 4S) form has aconitase activity while the fully apo (iron- free) form, know as Iron Regulatory Protein- 1 (IRP- 1) is devoid of enzymatic activity but plays an important role in regulating the intracellular iron level. www.oxisresearch.com /products/assays/21041/21041.shtml   (252 words)

Contrasting Sensitivities of Escherichia coli Aconitases A and B to Oxidation and Iron Depletion -- Varghese et al. 185 ... Contrasting Sensitivities of Escherichia coli Aconitases A and B to Oxidation and Iron Depletion -- Varghese et al. the primary aconitase because the lability of its exposed cluster It is commonly presumed that the demetallation of aconitases jb.asm.org /cgi/content/full/185/1/221   (6126 words)

Pfam 17.0 : Aconitase_C   (Site not responding. Last check: 2007-10-13) Aconitase, in its active form, contains a 4Fe-4S iron-sulphur cluster; three cysteine residues have been shown to be ligands of the 4Fe-4S cluster MEDLINE:2726740. Unlike the majority of iron-sulphur proteins that function as electron carriers, the Fe-S cluster of aconitase reacts directly with an enzyme substrate MEDLINE:8151704. In eukaryotes two isozymes of aconitase are known to exist: one found in the mitochondrial matrix and the other found in the cytoplasm. pfam.wustl.edu /cgi-bin/getdesc?name=Aconitase_C   (188 words)

Lauquin, Guy - ACO2, a gene encoding a second mitochondrial isoform of aconitase.   (Site not responding. Last check: 2007-10-13) When expressed on a multi-copy vector, ACO2 was able to functionally complement the glutamate auxotrophy of an aco1 mutant strain, the resulting aconitase activity being mainly located into mitochondria. In addition, under the conditions of glucose repression *delta*aco2 strains exhibited twice as much aconitase activity as the wild type. Taken together, these results show that: 1) the ACO2 gene encodes a second mitochondrial isoform of aconitase and 2) there is some regulatory interaction between ACO1 and ACO2. www.yeastgenome.org /yeast96/f2228.html   (286 words)

Genetic ablations of iron regulatory proteins 1 and 2 reveal why iron regulatory protein 2 dominates iron homeostasis ...   (Site not responding. Last check: 2007-10-13) Note that relative amounts of the two aconitases vary greatly between tissues and that cytosolic aconitase is mainly detected in the kidney, liver and brown fat. Kennedy MC, Mende-Mueller L, Blondin GA, Beinert H (1992) Purification, characterization of cytosolic aconitase from beef liver, its relationship to the iron-responsive element binding protein (IRE-BP). Coli: nucleotide sequence of the aconitase gene and amino acid sequence similarity with mitochondrial aconitases, the iron-responsive-element-binding protein and isopropylmala. embojournal.npgjournals.com /cgi/content/full/23/2/386   (6746 words)

Dietary Iron Intake Rapidly Influences Iron Regulatory Proteins, Ferritin Subunits and Mitochondrial Aconitase in Rat ...   (Site not responding. Last check: 2007-10-13) Aconitase activity was determined by the coupled assay of aconitase Time-dependent effect of dietary iron intake on the abundance of ferritin and mitochondrial aconitase (m-acon) in rat liver. and the abundance of ferritin and mitochondrial aconitase in rat www.nutrition.org /cgi/content/full/128/3/525   (7369 words)

Selective inhibition of the citrate-to-isocitrate reaction of cytosolic aconitase by phosphomimetic mutation of ... aconitases that are members of the latter two gene families. A phosphomimetic mutant impairs aconitase function in a yeast complementation assay. Extracts of transformed or nontransformed aco1 cells grown to mid-logarithmic phase (11) were assayed for aconitase activities. www.pnas.org /cgi/content/full/101/30/10907   (4735 words)

A Phosphomimetic Mutation at Ser-138 Renders Iron Regulatory Protein 1 Sensitive to Iron-Dependent Degradation -- ... Values correspond to results from triplicate samples; the aconitase activity is expressed as milliunits per microgram of recombinant protein. Values in panel B correspond to results from triplicate samples; the aconitase enzymatic activity is expressed as milliunits per microgram of total protein in the cytosolic lysate. Recombinant iron regulatory factor functions as an iron-responsive element-binding protein, a translational repressor and an aconitase: a functional assay for translational repression and direct demonstration of the iron switch. mcb.asm.org /cgi/content/full/23/19/6973   (4169 words)

Try your search on: Qwika (all wikis)

About us   |   Why use us?   |   Reviews   |   Press   |   Contact us   Copyright © 2005-2007 www.factbites.com Usage implies agreement with terms.