An investigation of the anion conducting pore of rat liver mitochondria.

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University of East Anglia , Norwich
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Open LibraryOL22690913M

Mitochondria in hepatocytes. As in all mitochondria, there are an outer membrane and an inner membrane, together creating two separate | Explore the latest full-text research PDFs, articles. An investigation of the anion conducting pore of rat liver mitochondria.

(Thesis) Warhurst IW. Publisher: University of East Anglia [] Metadata Source: The British Library Type: Thesis. Abstract. Highlight Terms No biological terms identified No abstract supplied.

An investigation of the anion conducting pore of rat liver mitochondria Author: Warhurst, I. ISNI: Awarding Body: University of East Anglia Current Institution: University of East Anglia Date of Award: Availability of Full Text.

Stimulation of the rat liver mitochondrial inner-membrane anion-conducting channel by aeration is dependent on the concentration of Ca 2+ ions in the assay medium.

Ca 2+ activates anion conduction in both aerated and non-energised mitochondria but acts over a wider concentration range and produces a greater increase in anion-conductivity in aerated by: 7. Stimulation of the rat liver mitochondrial inner-membrane anion-conducting channel by aeration is dependent on the concentration of Ca2+ ions in the assay medium.

Ca2+ activates anion conduction in both aerated and non-energised mitochondria but acts over a wider concentration range. Anion transport in sub-mitochondrial particles prepared from rat liver mitochondria Article (PDF Available) in Biochemical Society Transactions 14(6) December with 11 Reads. In conclusion, valinomycin-induced swelling of rat liver mitochondria in KC1 appears to be a complex process that may involve interactions between the ionophore, the KHexchanger and a hypothetical C1- porter, possibly the "pH-dependent anion- conducting pore" proposed by Selwyn et al.

Rat liver mitochondria were isolated from livers of overnight-fasted male Sprague–Dawley rats (– g) by differential centrifugation as described previously. Briefly, each liver was quickly excised, diced and homogenized in 40 ml of buffer A ( M sucrose, 2 mM HEPES, mM EGTA, pHadjusted with KOH).

Details An investigation of the anion conducting pore of rat liver mitochondria. PDF

Summary. Alkalinization of the matrix side of the mitochondrial inner membrane by pH shifts from to caused a reversible increase in current of ± pA (mean± se,n=21) at±40 mV measured using patch-clamp techniques. The current increase was reversed in a graded fashion by the addition of Mg 2+ in m KCl corresponds to approximately 15 pS.

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Nevertheless, considerable evidence has accumulated which suggests that heart and liver mitochondria contain a specific anion-conducting channel. In this review, a postulated inner membrane anion. liver mitochondria and rationalisation of the observa- tions in terms of a pH-dependent anion-conducting pore in the mitochondrial inner membrane.

This pore appears to open progressively with increasing pH over the range pH and also depends on the presence of free Ca’+ inside the mitochondria. The permeability transition (PT) denotes an increase of the mitochondrial inner membrane permeability to solutes with molecular masses up to about Da.

It is presumed to be mediated by opening of a channel, the permeability transition pore (PTP), whose molecular nature remains a mystery.

Here I briefly review the history of the PTP, discuss existing models, and present our new results. Mitochondria were isolated from imbibed seeds of lentil (Lens culinaris) and Phaseolus vulgaris.

We copurified two voltage-dependent anion channel from detergent solubilized mitochondria in a single purification step using hydroxyapatite. The two isoforms from P. vulgaris were separated by chromatofocusing chromatography in 4m urea without any loss of channel activity.

Beavis AD, Vercesi AE () Anion uniport in plant mitochondria is mediated by a mg(2+)-insensitive inner membrane anion channel. J Biol Chem – PubMed Google Scholar Bera AK, Ghosh S () Dual mode of gating of voltage-dependent anion channel as revealed by phosphorylation.

The current through mitochondrial chloride channels was first described in Subsequently, several types of ion channels permeable to chloride and other anions were found in the mitochondria of different origins. The increasing number of electrophysiological studies, however, yielded only more ambiguity rather than order in the field of chloride channels.

For import of radiolabelled proteins, rat liver mitochondria were used within 1 h after the isolation. The livers were obtained from animals of 80– g weight. Liver pieces were homogenized in buffer A ( mM sucrose, 2 mM EGTA, 10 mM Tris-HCl pH ) containing BSA (5 mg/ml, fatty acid free) and 1 mM PMSF using a Dounce homogenizer.

The ionic permeability of the outer mitochondrial membrane (OMM) was studied with the patch clamp technique. Electrical recording of intact mitochondria (hence of the outer membrane (OM)), derived from mouse liver, showed the presence of currents corresponding to low conductances.

AQP11, an AQP marked by an unusual pore‐forming NPA motif, was found to be expressed in mouse liver membranes. While the function of AQP11 as a water channel remains controversial [ 50, 51 ], of note is the phenotype expressed by the knockout mice lacking AQP11 as such mutant mice die before weaning as a consequence of the uraemia from.

Excessive generation of reactive oxygen species (ROS) in mitochondria and the opening of the nonselective mitochondrial permeability transition pore are important factors that promote cardiac pathologies and dysfunction.

The hormone melatonin (MEL) is known to improve the functional state of mitochondria via an antioxidant effect. Here, the effect of MEL administration on heart mitochondria. Activity of Phospholipase A2 in the Inner Membrane of Rat-Liver Mitochondria. European Journal of Biochemistry(3), DOI: /jtbx.

William Chefurka. Metabolism and compartmentation of endogenous fatty acids in aged mouse liver mitochondria. The mitochondrial permeability transition pore (mPTP or MPTP; also referred to as PTP, mTP or MTP) is a protein that is formed in the inner membrane of the mitochondria under certain pathological conditions such as traumatic brain injury and g allows increase in the permeability of the mitochondrial membranes to molecules of less than Daltons in molecular weight.

Rat and mouse liver mitochondria were isolated as described previously (De Pinto et al., ). Briefly, livers, from male Donryu rats, wild-type mice. As for the anion channels present in the inner membrane of mammalian mitochondria, it has been established by means of classical swelling experiments that heart and liver mitochondria contain a non-selective anion-conducting channel, known as the inner membrane anion channel (IMAC) (Garlid and Beavis ).

IMAC catalyzes the electrophoretic. MST analysis was performed using a NanoTemper Monolith NT apparatus, as recently described. 60 Briefly, purified rat liver mitochondrial VDAC1 was fluorescently labeled using the.

A study on freeze-fractured isolated liver mitochondria. Biochim Biophys Acta. Feb 8; (3)– McEnery MW, Snowman AM, Trifiletti RR, Snyder SH. Isolation of the mitochondrial benzodiazepine receptor: association with the voltage-dependent anion channel and the adenine nucleotide carrier.

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Kraayenhof R, van Dam K. Interaction between uncouplers and substrates in rat-liver mitochondria. Biochim Biophys Acta. Feb 25; (2)– Quagliariello E, Palmieri F. Control of succinate oxidation by succinate-uptake by rat-liver mitochondria.

Eur J Biochem. Mar; 4 (1)– van Dam K, Slater EC. The TSPO/VDAC/ANT hypothesis for PTP formation is not supported by genetic ablation experiments as the pore could still be detected in mouse liver mitochondria where both ANT1 and ANT2 isoforms had been eliminated, in mitochondria of VDAC1‐null mice, in cells without VDAC1, 2 and 3 and in mitochondria with selective ablation of TSPO.

The matrix space of mitochondria is surrounded by two membranes. The mitochondrial inner membrane contains the respiration chain and a large number of highly specific carriers for the mostly anionic substrates of mitochondrial metabolism.

In contrast to this the permeability properties of the mitochondrial outer membrane are by far less specific. It acts as a molecular sieve for hydrophilic. Mitochondrial permeability transition pore (PTP), a (patho)physiological phenomenon discovered over 40 years ago, is still not completely understood.

PTP activation results in a formation of a nonspecific channel within the inner mitochondrial membrane with an exclusion size of kDa.

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PTP openings can be transient and are thought to serve a physiological role to allow quick Ca2+. Experimental buffer for cell and mouse-liver mitochondria (EB c) To prepare ml of EB c, mix ml of 1 M KCl, 1 ml of 1 M Tris/MOPS, 10 ml of μl M EGTA/Tris and μl of Pi.Mitochondria with expanded matrical chambers have been produced by the addition of valinomycin to the medium, which produces a rapid potassium ion influx.

This has been demonstrated with isolated rat liver mitochondria (Butler and Judha, ) and also with the washed Ehrlich ascites cells mentioned earlier. The addition of calcium chloride or. The food channel, VDAC.

A decade before we trained our micropipettes to chase tiny mitochondria in suspension, VDAC conductance was reconstituted in phospholipid bilayers [].A great deal of information has been collected about this voltage dependent anion-selective channel over the past 30 years using electrophysiological, biochemical and functional approaches [].