Mitochondrial function

The aim of our in vitro study was to assess the potential effect of BPF on H295R cells mitochondrial activity, metabolic activity, membrane integrity, lysosomal function, and testosterone synthesis. Adrenocortical carcinoma cells were cultivated during 24 h in the presence of BPF (0.1, 0.5, 1, 10, 25, 50, 75, 100, 300, 500 μM). Exposure doses of BPF caused a significant decrease of mitochondrial activity starting from 1 μM, we observed a slight increase in mitochondrial activity at the lowest concentration (0.1 μM).

4p mudbound 10-12-2021 13 1   Download

This study was carried out to evaluate the effect of Cobalt chloride (CoCl2) on cardiac mitochondrial function in an in vitro model. In the study, H9C2 cardiomyocytes were cultured in a medium containing different concentrations of CoCl2. Cell viability, cardiolipin content, mitochondrial function, and mitochondrial oxidative stress were assessed by using Cell Counting Kit-8 and suitable fluorescence kits.

6p guitaracoustic02 08-12-2021 5 2   Download

The expression of mitochondrial and hydrogenosomal ADP/ATP carriers (AACs) from plants, rat and the anaerobic chytridiomycete fungus Neocallimastix spec. L2 in Escherichia coli allows a functional integration of the recombinant proteins into the bacterial cytoplasmic membrane. For AAC1 and AAC2 from rat, apparent Km values of about 40 lM for ADP, and 105 lM or 140 lM, respectively, for ATP have been determined, similar to the data reported for isolated rat mitochondria.

10p system191 01-06-2013 36 3   Download

Mitochondrial functional and structural impairment and generation of oxidative stress have been implicated in aging, various diseases and chemotherapies. This study analyzed azidothymidine (AZT)-caused failures in mitochondrial functions, in redox regulation and activation of the HIV-1 gene expression. We monitored intracellular concentrations of ATP and glutathione (GSH) as the indicators of energy production and redox conditions, respectively, during the time-course experiments with U937 and MOLT4 human lymphoid cells in the presence of AZT (0.05 mgÆmL)1) or H2O2 (0.01 mM) for 15–25 days.

7p system191 01-06-2013 42 3   Download

Cellular manifestations of aging are most pronounced in postmitotic cells, such as neurons and cardiac myocytes. Alterations of these cells, which are responsible for essential functions of brain and heart, are particularly important contributors to the overall aging process. Mitochondria and lysosomes of postmitotic cells suffer the most remarkable age-related alterations of all cellular organelles.

7p research12 01-06-2013 41 5   Download

A severe challenge to the idea that mitochondrial DNA mutations play a major role in the aging process in mammals is that clear loss-of-function mutations accumulate only to very low levels (under 1% of total) in almost any tissue, even by very old age. Their accumulation is punctate: some cells become nearly devoid of wild-type mitochondrial DNA and exhibit no activity for the partly mitochondrially encoded enzyme cytochrome c oxidase. Such cells accumulate in number with aging, suggesting that they survive indefinitely, which is itself paradoxical....

7p research12 01-06-2013 27 3   Download

The oxidant function of pro-apoptotic protein Bax was investigated through heterologous expression in yeast. Direct measurements of fatty acid content show that Bax-expression induces oxidation of mitochondrial lipids. This effect is prevented by the coexpression of Bcl-xL. The oxi-dation actually could be followed on isolated mitochondria as respiration-induced peroxidation of polyunsaturatedcis-parinaric acid and on whole cells as the increase in the amount of thiobarbituric acid-reactiveproducts. ...

11p tumor12 22-04-2013 37 2   Download

To examine whether valinomycin induces a mitochondrial permeability transition (PT), we investigated its effects on mitochondrial functions under various conditions. The acceleration of mitochondrial respiration and swelling, induced by valinomycin, were found to be insensitive to inhibitors of the ordinary PT, indicating that valinomycin does not induce the ordinary PT. Results of experiments usingmitochondria isolated fromtransgenicmice expressing human bcl-2 also supported this conclusion.

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The new antigen receptor (IgNAR) from sharks is a disul-phide bonded dimer of two protein chains,each containing one variable and five constant domains,and functions as an antibody. In order to assess the antigen-binding capabilities of isolated IgNAR variable domains (VNAR),we have con-structed anin vitro library incorporating synthetic CDR3 regions of 15–18 residues in length.

12p tumor12 20-04-2013 26 3   Download

The crystal structure of theSchizosaccharomyces pombe Holliday junction resolvase Ydc2 revealed significant struc-tural homology with the Escherichia coliresolvase RuvC but Ydc2 contains a small triple helical bundle that has no equivalent in RuvC.Two of thea-helices that form this bundle show homology to a putative DNA-binding motif known as SAP.To investigate the biochemical function of the triple-helix domain, truncated Ydc2 mutants were expressed inE.coliand in fission yeast.

11p fptmusic 16-04-2013 35 4   Download

Aging is accompanied by a gradual deterioration of cell functions. Mitochondrial dysfunction and accumulation of protein damage have been proposed to contribute to this process. The present study was carried out to examine the effects of aging in mitochondrial matrix isolated from rat liver. The activity of Lon protease, an enzyme implicated in the degradation of abnormal matrix proteins, was meas-ured and the accumulation of oxidation and glycoxidation (N e -carboxymethyllysine, CML) products was monitored using immunochemical assays....

8p fptmusic 16-04-2013 26 2   Download

3-Hydroxyacyl-CoA dehydrogenase (HAD) functions in mitochondrial fatty acid b-oxidation by catalyzing the oxidation of straight chain 3-hyd-roxyacyl-CoAs. HAD has a preference for medium chain substrates, whereas short chain 3-hydroxyacyl-CoA dehydrogenase (SCHAD) acts on a wide spectrum of substrates, including steroids, cholic acids, and fatty acids, with a preference for short chain methyl-branched acyl-CoAs.

10p fptmusic 12-04-2013 33 3   Download

Fromin vivo models of stroke it is known that ischemia⁄reperfusion indu-ces oxidative stress that is accompanied by deterioration of brain mito-chondria. Previously, we reported that the increase in Ca 2+ induces functional breakdown and morphological disintegration in brain mitochon-dria subjected to hypoxia⁄reoxygenation (H⁄R). Protection by ADP indica-ted the involvement of the mitochondrial permeability transition pore in the mechanism of membrane permeabilization.

9p fptmusic 11-04-2013 25 1   Download

Among the eukaryotic members of the Hsp70 family, mitochondrial Hsp70 shows the highest degree of sequence identity with bacterial DnaK. Although they share a functional mechanism and homologous co-chaper-ones, they are highly specific and cannot be exchanged betweenEscherichia coliand yeast mitochondria.

13p fptmusic 11-04-2013 30 1   Download

3,3¢-Dipropyl-2,2¢-thiadicarbocyanine iodide [DiS-C3 (5)], often used as a tracer dye to assess the mitochondrial mem-brane potential, was investigated in detail regarding its effects on the structure and function of isolated mitochon-dria. As reported previously, DiS-C3(5) had an inhibitory effect on NADH-driven mitochondrial electron transfer. On the contrary, in the presence of inorganic phosphate, DiS-C3(5) showed dose-dependent biphasic effects on mito-chondria energized by succinate. At higher concentrations, such as 50lM,DiS-C3(5) acceleratedmitochondrial oxygen consumption. ...

0p awards 05-04-2013 35 2   Download

The ESSS protein is a recently identified subunit of mam-malian mitochondrial complex I. It is a relatively small integral membrane protein (122 amino acids) found in the b-subcomplex. Genomic sequence database searches reveal its localization to theX-chromosome inhumans andmouse. TheESSScDNAfromChinesehamster cellswas clonedand shown to complement one complementation group of our previously described mutants with a proposed X-linkage. Sequence analyses of the ESSS cDNA in these mutants revealed chain termination mutations. ...

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Information on the regulation and structure–function rela-tion of enzymes involved in DNA precursor synthesis is pivotal, as defects in several of these enzymes have been found to cause depletion or deletion of mitochondrial DNA resulting in severediseases.Here, the effect of aminoacid106 on the enzymatic properties of the cell-cycle-regulated human cytosolic thymidine kinase 1(TK1) is investigated.

9p dell39 03-04-2013 50 4   Download

The mitochondrial cytochromeb missense mutation, G167E, has been reported inapatientwithcardiomyopathy. The residue G167 is located in an extramembranous helix close to the hinge region of the iron–sulfur protein. In order to characterize the effects of the mutation on the structure and function of thebc1complex, we introducedG167E into the highly similar yeast cytochromeb. The mutation had a severe effect on the respiratory function, with the activity of thebc1complex decreased to a fewper cent of the wild type....

7p dell39 03-04-2013 44 5   Download

The cytochromebc1 complex of the yeastSaccharomyces cerevisiae is composed of 10 different subunits that are assembledas a symmetrical dimer in the innermitochondrial membrane. Three of the subunits contain redox centers and participate in catalysis, whereas little is known about the function of the seven supernumerary subunits.

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Mitochondrialb-oxidation is a complex pathway involving, in the case of saturated straight chain fatty acids of even carbonnumber, at least 16proteinswhichare organized into two functional subdomains; one associated with the inner face of the inner mitochondrial membrane and the other in the matrix. Overall, the pathway is subject to intramito-chondrial control at multiple sites. However, at least in the liver, carnitine palmitoyl transferase I exerts approximately 80% of control over pathway flux under normal conditions....

8p dell39 03-04-2013 40 2   Download