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Abstract
1. Synthesized 2-n-nonyl-4-hydroxy[3-3H]quinoline N-oxide ([3H]NoHOQnO) is a powerful inhibitor of both NADH oxidase and succinate oxidase activities in submitochondrial particles from beef heart. 2. The binding of [3H]NoHOQnO to submitochondrial particles reveals one specific binding site, which is sensitive to antimycin, and a large amount of aspecific binding. 3. The content of [3H]NoHOQnO-specific binding sites is related to the cytochrome b content in the particles. 4. The binding of [3H]NoHOQnO to the specific site causes the inhibition of electron transfer. 5. The relation between the inhibition of NADH oxidation and [3H]NoHOQnO-specific binding is hyperbolic.
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2
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Megli FM, Mattiazzi M, Di Tullio T, Quagliariello E. Annexin V binding perturbs the cardiolipin fluidity gradient in isolated mitochondria. Can it affect mitochondrial function? Biochemistry 2000; 39:5534-42. [PMID: 10820027 DOI: 10.1021/bi992779z] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The phosholipid bilayer fluidity of isolated mitochondria and phospholipid vesicles after calcium-dependent binding of annexin V was studied using EPR spectroscopy. The membranes were probed at different depths by alternatively using cardiolipin, phosphatidylcholine, or phosphatidylethanolamine spin labeled at position C-5 or C-12 or C-16 of the beta acyl chain. Computer-aided spectral titration facilitated observing and quantitating the EPR spectrum from phospholipid spin labels affected by annexin binding, and spectral mobility was calibrated by comparison with standard spectra scanned at various temperatures. In most cases it was found that binding of the protein to the membranes makes the inner bilayer more rigid up to acyl position C-12 than afterward, in agreement with the previously observed effect in SUVs [Megli, F. M., Selvaggi, M., Liemann, S., Quagliariello, E., and Huber, R. (1998) Biochemistry 37, 10540-10546]. Moreover, in isolated mitochondrial membranes, cardiolipin apparently is more readily affected than the other main phospholipids, while in vesicles made from mitochondrial phospholipids, the different species are affected in essentially the same way. This behavior is consistent with the existence of distinct cardiolipin pools in mitochondria, and with the already advanced hypothesis that these domains are the binding site for annexin V to the isolated organelles [Megli, F. M., Selvaggi, M., De Lisi, A., and Quagliariello, E. (1995) Biochim. Biophys. Acta 1236, 273-278]. Keeping in mind the funcional importance of cardiolipin in the mitochondrial membrane, the question is raised as to whether the observed influence of annexin V binding to this phospholipid and its consequent local fluidity alteration might affect the mitochondrial functionality, at least in vitro.
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Affiliation(s)
- F M Megli
- Dipartimento di Biochimica e Biologia Molecolare, Università di Bari, V. Orabona, 4, 70126 Bari, Italy
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3
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Loguercio Polosa P, Roberti M, Musicco C, Gadaleta MN, Quagliariello E, Cantatore P. Cloning and characterisation of mtDBP, a DNA-binding protein which binds two distinct regions of sea urchin mitochondrial DNA. Nucleic Acids Res 1999; 27:1890-9. [PMID: 10101198 PMCID: PMC148398 DOI: 10.1093/nar/27.8.1890] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
The cDNA for the sea urchin mitochondrial D-loop-binding protein (mtDBP), a 40 kDa protein which binds two homologous regions of mitochondrial DNA (the D-loop region and the boundary between the oppositely transcribed ND5 and ND6 genes), has been cloned. Four different 3'-untranslated regions have been detected that are related to each other in pairs and do not contain the canonical polyadenylation signal. The in vitro synthesised mature protein (348 amino acids), deprived of the putative signal sequence, binds specifically to its DNA target sequence and produces a DNase I footprint identical to that given by the natural protein. mtDBP contains two leucine zippers, one of which is bipartite, and two small N- and C-terminal basic domains. A deletion mutation analysis of the recombinant protein has shown that the N-terminal region and the two leucine zippers are necessary for the binding. Furthermore, evidence was provided that mtDBP binds DNA as a monomer. This rules out a dimerization role for the leucine zippers and rather suggests that intramolecular interactions between leucine zippers take place. A database search has revealed as the most significative homology a match with the human mitochondrial transcription termination factor (mTERF), a protein that also binds DNA as a monomer and contains three leucine zippers forming intramolecular interactions. These similarities, and the observation that mtDBP-binding sites contain the 3'-ends of mtRNAs coded by opposite strands and the 3'-end of the D-loop structure, point to a dual function of the protein in modulating sea urchin mitochondrial DNA transcription and replication.
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Affiliation(s)
- P Loguercio Polosa
- Dipartimento di Biochimica e Biologia Molecolare, Università di Bari and the Centro Studi sui Mitocondri e Metabolismo Energetico, CNR, Via Orabona 4, 70125 Bari, Italy
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4
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Valenti D, Barile M, Quagliariello E, Passarella S. Inhibition of nucleoside diphosphate kinase in rat liver mitochondria by added 3'-azido-3'-deoxythymidine. FEBS Lett 1999; 444:291-5. [PMID: 10050777 DOI: 10.1016/s0014-5793(99)00071-x] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
The effect of 3'-azido-3'-deoxythymidine on nucleoside diphosphate kinase of isolated rat liver mitochondria has been studied. This is done by monitoring the increase in the rate of oxygen uptake by nucleoside diphosphate (TDP, UDP, CDP or GDP) addition to mitochondria in state 4. It is shown that 3'-azido-3'-deoxythymidine inhibits the mitochondrial nucleoside diphosphate kinase in a competitive manner, with a Ki value of about 10 microM as measured for each tested nucleoside diphosphate. It is also shown that high concentrations of GDP prevent 3'-azido-3'-deoxythymidine inhibition of the nucleoside diphosphate kinase.
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Affiliation(s)
- D Valenti
- Dipartimento di Biochimica e Biologia Molecolare, Università di Bari, and Centro di Studi sui Mitocondri e Metabolismo Energetico, C.N.R., Italy.
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5
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Abstract
1. The subject of this review is the interaction between AZT (zidovudine) and mitochondria as described in papers dealing with AZT therapy both in AIDS patients and in model systems--that is, in cultured cells and in isolated mitochondria. 2. The structure and function of mitochondria are briefly described with discussion of the theoretical frame for a detailed bioenergetic investigation. 3. Experimental work is reported showing that mitochondria are cell AZT targets: changes in the structure and function induced by long-term AZT therapy as investigated both in AIDS patients and in model systems. 4. The AZT inhibition of energy-supplying reactions is considered in detail in studies dealing with long-term treatment and studies in which AZT was added to isolated mitochondria. In particular, adenylate kinase, ADP/ATP translocase and DNA polymerase gamma are reported as molecular targets of AZT. 5. Some perspectives of AZT therapy from the study of the effect of AZT on mitochondrion biochemistry are briefly reported.
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Affiliation(s)
- M Barile
- Dipartimento di Biochimica e Biologia Molecolare, Università degli Studi di Bari, and Centro di Studio sui Mitocondri e Metabolismo Energitico C.N.R., Italy.
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6
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Barile M, Valenti D, Brizio C, Quagliariello E, Passarella S. Rat liver mitochondria can hydrolyse thiamine pyrophosphate to thiamine monophosphate which can cross the mitochondrial membrane in a carrier-mediated process. FEBS Lett 1998; 435:6-10. [PMID: 9755848 DOI: 10.1016/s0014-5793(98)01007-2] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
We show here that TPP --> TMP conversion can take place in rat liver mitochondria. This occurs via the novel, putative TPP pyrophosphatase localised in the mitochondrial matrix, as shown both by digitonin titration and by an HPLC enzyme assay carried out on the mitochondrial matrix fraction. Certain features of the reaction, including the substrate and pH dependence, are reported. Additional evidence is given that externally added TMP can cross the mitochondrial membrane in a manner consistent with the occurrence of a carrier-mediated process. This can occur both via the TPP translocator and via a novel translocator, inhibited by CAT but different from the ADP/ATP carrier.
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Affiliation(s)
- M Barile
- Dipartimento di Biochimica e Biologia Molecolare, Università di Bari, Italy.
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7
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Megli FM, Selvaggi M, Liemann S, Quagliariello E, Huber R. The calcium-dependent binding of annexin V to phospholipid vesicles influences the bilayer inner fluidity gradient. Biochemistry 1998; 37:10540-6. [PMID: 9671526 DOI: 10.1021/bi9801255] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
The fluidity of the hydrophobic interior of phospholipid vesicles after calcium-dependent binding of human annexin V (AVH) was studied using EPR spectroscopy. Vesicles (SUVs) composed of PC or PE and an acidic phospholipid (alternatively PS, PA, or CL) were probed at different bilayer depths by either phosphatidylcholine, or the accompanying acidic phospholipid, bearing a spin label probe at position C-5, C-12, or C-16 of the sn-2 acyl chain. Alternatively, the vesicle surface was probed with a polar head spin labeled PE (PESL). The EPR spectra of annexin-bound bilayer domain(s) were obtained by computer spectral subtraction. The order parameter values (S) from the resulting difference spectra revealed that the bilayer hydrophobic interior has a greatly altered fluidity gradient, with an increased rigidity up to the C-12 position. Thereafter, the rigidification progressively vanished. The effect is not linked to the phospholipid class, since all the acidic phospholipid spectra, as well as phosphatidylcholine, shared the same sensitivity to the bound protein. The observed membrane rigidification appears to parallel the "crystallizing" tendency of vesicle-bound annexin V, but may not be involved in the calcium channeling activity of this protein.
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Affiliation(s)
- F M Megli
- Centro di Studio sui Mitocondri e Metabolismo Energetico, Dipartimento di Biochimica e Biologia Molecolare, Università di Bari, Italy
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8
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Abstract
Rat heart mitochondrial membranes exposed to the free radicals generating system tert-butylhydroperoxide/Cu2+ undergo lipid peroxidation as evidenced by the accumulation of thyobarbituric acid reactive substances. Mitochondrial lipid peroxidation resulted in a marked loss of both cytochrome c oxidase activity and cardiolipin content. The alterations in the properties of cytochrome c oxidase were confined to a decrease in the maximal activity (Vmax) with no change in the affinity (Km) with respect to the substrate cytochrome c. Various lipid soluble antioxidants could prevent the lipid peroxidation reaction and the associated loss of cytochrome c oxidase activity. External added cardiolipin but no other phospholipids, nor peroxidized cardiolipin was able to prevent the loss of cytochrome oxidase activity induced by lipid peroxidation. These results establish a close correlation between oxidative damage to cardiolipin and alterations in the cytochrome oxidase activity and may prove useful in probing molecular mechanism of free radicals induced peroxidative damage of mitochondria which has been proposed to contribute to aging and to chronic degenerative diseases.
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Affiliation(s)
- G Paradies
- Department of Biochemistry and Molecular Biology, University of Bari, Italy
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9
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Paradies G, Ruggiero FM, Petrosillo G, Quagliariello E. Alterations in carnitine-acylcarnitine translocase activity and in phospholipid composition in heart mitochondria from hypothyroid rats. Biochim Biophys Acta 1997; 1362:193-200. [PMID: 9540850 DOI: 10.1016/s0925-4439(97)00075-6] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Changes in mitochondrial fatty acid metabolism may underlie the decline in cardiac function in the hypothyroid animals. The effect of hypothyroidism on fatty acid oxidation, carnitine-acylcarnitine translocase activity and lipid composition in rat heart mitochondria has been examined. Rates of mitochondrial fatty acid oxidation as well as carnitine-carnitine and carnitine-palmitoylcarnitine exchange reactions were all depressed in heart mitochondria isolated from hypothyroid rats. Kinetic analysis of the carnitine-carnitine exchange reaction showed that the hypothyroid state affects the Vmax of this process, while having no effect on the K(m) value. Heart mitochondrial inner membrane lipid composition was significantly altered in hypothyroid rats. Cardiolipin, particularly, was found to decrease (by around 36%). Alterations in fatty acid pattern of mitochondrial inner membrane preparations from hypothyroid rats were also found. The effects of the hypothyroid state on fatty acids oxidation, carnitine translocase activity and phospholipid composition were completely reversed by following treatment of hypothyroid rats with thyroid hormone. A lower cardiolipin content in the mitochondrial inner membrane offers a plausible mechanism to explain the decline in the translocase activity in hypothyroidism.
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Affiliation(s)
- G Paradies
- Department of Biochemistry and Molecular Biology, University of Bari, Italy
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10
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Barile M, Brizio C, De Virgilio C, Delfine S, Quagliariello E, Passarella S. Flavin adenine dinucleotide and flavin mononucleotide metabolism in rat liver--the occurrence of FAD pyrophosphatase and FMN phosphohydrolase in isolated mitochondria. Eur J Biochem 1997; 249:777-85. [PMID: 9395326 DOI: 10.1111/j.1432-1033.1997.00777.x] [Citation(s) in RCA: 51] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
In order to gain some insight into mitochondrial flavin biochemistry, rat liver mitochondria essentially free of lysosomal and microsomal contamination were prepared and their capability to metabolise externally added and endogenous FAD and FMN tested both spectroscopically and via HPLC. The existence of two novel mitochondrial enzymes, namely FAD pyrophosphatase (EC 3.6.1.18) and FMN phosphohydrolase (EC 3.1.3.2), which catalyse FAD-->FMN and FMN-->riboflavin conversion, respectively, is shown. They differ from each other and from extramitochondrial enzymes, as judged by their pH profile and inhibitor sensitivity, and can be separated in a partial FAD pyrophosphatase purification. Digitonin titration and subfractionation experiments show that FAD pyrophosphatase is located in the outer mitochondrial membrane and FMN phosphohydrolase in the intermembrane space. Since these enzymes can metabolise endogenous FAD and FMN, which are made available by using both Triton X-100 and the effector oxaloacetate, a proposal is made that FAD pyrophosphatase and FMN phosphohydrolase play a major role in mitochondrial flavoprotein turnover.
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Affiliation(s)
- M Barile
- Dipartimento di Biochimica e Biologia Molecolare, Università di Bari, and Centro di Studio sui Mitocondri e Metabolismo Energetico, C.N.R., Italy.
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11
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Roberti M, Musicco C, Loguercio Polosa P, Gadaleta MN, Quagliariello E, Cantatore P. Purification and characterization of a mitochondrial, single-stranded-DNA-binding protein from Paracentrotus lividus eggs. Eur J Biochem 1997; 247:52-8. [PMID: 9249008 DOI: 10.1111/j.1432-1033.1997.00052.x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
A binding protein for single-stranded DNA was purified from Paracentrotus lividus egg mitochondria to near homogeneity by chromatography on DEAE-Sephacel and single-stranded-DNA-cellulose. The protein consists of a single polypeptide of about 15 kDa. Glycerol gradient sedimentation analysis suggested that P. lividus mitochondrial single-stranded-DNA-binding protein exists as a homo-oligomer, possibly a tetramer, in solution. The protein shows a stronger preference for poly(dT) with respect to single-stranded M13, poly(dI) and poly(dC). Binding to poly(dA) takes place with much lower affinity. The binding-site size, determined by gel mobility-shift experiments with oligonucleotides of different length, is approximately 45 nucleotides. The binding to single-stranded DNA occurs with low or no cooperativity and is not influenced by ionic strength. The protein has a very high affinity for the DNA: its apparent macroscopic association constant is 2x10(9) M(-1), a value which is the highest among the mitochondrial single-stranded-DNA-binding proteins characterized to date. The lack of cooperativity and the high association constant represent distinctive features of this protein and might be related to the peculiar mechanism of sea urchin mitochondrial DNA replication.
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Affiliation(s)
- M Roberti
- Department of Biochemistry and Molecular Biology, University of Bari and Centro Studi sui Mitocondri e Metabolismo Energetico, CNR, Italy
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12
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Paradies G, Ruggiero FM, Petrosillo G, Quagliariello E. Age-dependent decline in the cytochrome c oxidase activity in rat heart mitochondria: role of cardiolipin. FEBS Lett 1997; 406:136-8. [PMID: 9109403 DOI: 10.1016/s0014-5793(97)00264-0] [Citation(s) in RCA: 123] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Cardiolipin is a major mitochondrial membrane lipid and plays a pivotal role in mitochondrial function. We have recently suggested a possible involvement of this phospholipid in the age-linked decline of cytochrome c oxidase activity in rat heart mitochondria [G. Paradies et al. (1993) Arch. Gerontol. Geriatr. 16, 263-272]. The aim of this work was to test our earlier proposal. We have investigated whether addition of exogenous cardiolipin to mitochondria is able to reverse, in situ, the age-linked decrease in the cytochrome oxidase activity. The method of fusion of liposomes with mitochondria developed by Hackenbrock [Hackenbrock and Chazotte (1986) Methods Enzymol. 125, 35-45] was employed in order to enrich the mitochondria cardiolipin content. We demonstrate that the lower cytochrome c oxidase activity in heart mitochondria from aged rats can be fully restored to the level of young control rats by exogenously added cardiolipin. No restoration was obtained with other phospholipids or with peroxidized cardiolipin. Our data support a key role for cardiolipin in the age-linked decline of rat heart mitochondrial cytochrome c oxidase activity.
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Affiliation(s)
- G Paradies
- Department of Biochemistry and Molecular Biology, University of Bari, Italy
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13
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Barile M, Valenti D, Passarella S, Quagliariello E. 3'-Azido-3'-deoxythmidine uptake into isolated rat liver mitochondria and impairment of ADP/ATP translocator. Biochem Pharmacol 1997; 53:913-20. [PMID: 9174103 DOI: 10.1016/s0006-2952(96)00831-3] [Citation(s) in RCA: 66] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
To gain some insight into the mechanism by which 3'-azido-3'-deoxythymidine (AZT) impairs mitochondrial metabolism, [14C]AZT uptake by rat liver mitochondria (RLM) in vitro was investigated. AZT accumulated in mitochondria in a time-dependent manner and entered the mitochondrial matrix. The rate of AZT uptake into mitochondria showed a hyperbolic dependence on the drug concentration and was inhibited by mersalyl, a thiol reagent that cannot enter mitochondria, thus showing that a membrane protein is involved in AZT transport. Investigation into the capability of AZT to affect certain mitochondrial carriers demonstrated that AZT was able to impair the ADP/ATP translocator, but had no effect on Pi, dicarboxylate, tricarboxylate, or oxodicarboxylate carriers. AZT inhibited ADP/ATP antiport in either mitochondria or mitoplasts in a competitive manner with different sensitivity (Ki values were 18.3 +/- 2.9 and 70.2 +/- 5.8 microM, respectively). Consistent with this were isotopic measurements showing that AZT accumulates in the intermembrane space. AZT does not use ADP/ATP carrier to enter mitochondria, as shown by the failure of both carboxyatractyloside (CAT) to inhibit AZT transport into mitochondria and AZT to induce ATP efflux from ATP-loaded mitochondria. ADP/ATP translocator impairment by AZT as one of the biochemical processes responsible for the ATP deficiency syndrome is discussed.
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Affiliation(s)
- M Barile
- Dipartimento di Biochimica e Biologia Molecolare, Università di Bari, Centro di Studio sui Mitocondri e Metabolismo Energetico, Italy
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14
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Paradies G, Ruggiero FM, Petrosillo G, Quagliariello E. Stimulation of carnitine acylcarnitine translocase activity in heart mitochondria from hyperthyroid rats. FEBS Lett 1996; 397:260-2. [PMID: 8955359 DOI: 10.1016/s0014-5793(96)01190-8] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
The effect of hyperthyroidism on fatty acid oxidation and on carnitine-acylcarnitine translocase activity in rat heart mitochondria has been studied. The rates of palmitoylcarnitine supported respiration as well as the carnitine-palmitoylcarnitine exchange reaction were both stimulated (approx. 36%) in heart mitochondria from hyperthyroid rats. Kinetic analysis of the carnitine-carnitine exchange reaction showed that thyroid hormone affects the Vmax of this process, while having no effect on the Km values. The level of cardiolipin was significantly higher (approx. 40%) in heart mitoplasts from hyperthyroid rats than from the control rats. It can be concluded that thyroid hormones produce a stimulation of heart mitochondrial carnitine translocase activity and that the basis of this effect is likely an increase in the cardiolipin content.
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Affiliation(s)
- G Paradies
- Department of Biochemistry and Molecular Biology and CNR Unit for the Study of Mitochondria and Bioenergetics, University of Bari, Italy
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15
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Atlante A, Passarella S, Pierro P, Di Martino C, Quagliariello E. The mechanism of proline/glutamate antiport in rat kidney mitochondria. Energy dependence and glutamate-carrier involvement. Eur J Biochem 1996; 241:171-7. [PMID: 8898903 DOI: 10.1111/j.1432-1033.1996.0171t.x] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Proline/glutamate antiport in rat kidney mitochondria has been studied in terms of two different features: energy dependence and glutamate-carrier contribution to accomplish proline movement across the mitochondrial membrane. Energy dependence of the proline/glutamate antiporter in rat kidney mitochondria has been investigated by means of both spectroscopic measurements and isotopic techniques, using either normal or [14C]glutamate-loaded mitochondria. The sensitivity of the proline/glutamate antiport to the ionophores valinomycin and nigericin, under conditions in which delta psi and delta pH are selectively affected, shows that the exchange is energy dependent. Measurements of both membrane potential and proton movement across the mitochondrial membrane suggest that proline/glutamate antiport is driven by the electrochemical proton gradient via the delta psi dependent proline/glutamate translocator and delta pH-dependent glutamate/OH- carrier. Such a carrier provides for re-uptake of glutamate that has already passed out of the mitochondria in exchange with incoming proline, made possible by the existence of a separate pool of glutamate in the intermembrane space, directly shown by means of HPLC measurements.
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Affiliation(s)
- A Atlante
- Centro di Studio sui Mitocondri e Metabolismo Energetico, C. N. R., Bari, Italy
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16
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Liuzzi GM, Tamborra R, Ventola A, Bisaccia F, Quagliariello E, Riccio P. Different recognition by clostripain of myelin basic protein in the lipid-free and lipid-bound forms. Biochem Biophys Res Commun 1996; 226:566-71. [PMID: 8806674 DOI: 10.1006/bbrc.1996.1395] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Different proteolytic enzymes were tested for their ability to degrade the myelin basic protein of the central nervous system, purified in two different forms, the lipid-free form and the lipid-bound form. As shown by SDS gel electrophoresis only clostripain, a thiol protease, was able to distinguish between the two MBPs since it degraded MBP only in the lipid-free form. The failure to degrade lipid-bound MBP by clostripain could not be ascribed to the presence of lipids, since the other proteolytic enzymes tested degraded both MBPs independently from lipids giving fragments with different size. These results may be related to different conformations of MBPs possibly relevant for the study of myelin structure and antigenic properties of the protein.
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Affiliation(s)
- G M Liuzzi
- Department of Biochemistry and Molecular Biology, University of Bari, Italy
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17
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Perlino E, Ciampolillo A, Maenza S, Marra E, Derobertis O, Ambrosi A, Giorgino R, Quagliariello E. Increased expression of insulin-like growth factor 1 (IGF-1) in multinodular non toxic goiter. Oncol Rep 1996; 3:753-7. [PMID: 21594449 DOI: 10.3892/or.3.4.753] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
Abstract
Thyroid cell growth and function both in vivo and in vitro, are mainly regulated by TSH. Recent studies have shown that growth factors including insulin-like growth factors (IGF-1) have an important role in the control of thyrocyte proliferation and differentiation. The aim of this study was to evaluate the expression of the IGF-1 gene by Northern analysis and the IGF-1 tissue protein by radioimmunoassay in multinodular euthyroid goiters. The study population consisted of 20 patients with multinodular goiter (14 females and 6 males) living in a non endemic geographic area. All patients were euthyroid at the time of surgery and submitted to total or subtotal thyroidectomy. Samples of normal thyroid tissue were obtained from three patients who were operated due to laryngeal carcinomas. The IGF-1 protein content was increased in non toxic multinodular goiter, 22 ng/g vs. 14 in controls (p<0.03), as was IGF-1 gene expression (p<0.05). The increase in the steady state mRNA content correlated with the increase in the protein content (r=0.665; p<0.005). These results suggest that IGF-1 may play a role in proliferation events involved in benign hyperplastic thyroid diseases.
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Affiliation(s)
- E Perlino
- UNIV BARI,FAC SCI,DEPT BIOCHEM & MOLEC BIOL,BARI,ITALY. UNIV BARI,FAC MED,MED ENDOCRINOL & METAB DIS INST,BARI,ITALY. UNIV BARI,FAC MED,DEPT SURG 1,BARI,ITALY
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18
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Paradies G, Ruggiero FM, Petrosillo G, Quagliariello E. Age-dependent impairment of mitochondrial function in rat heart tissue. Effect of pharmacological agents. Ann N Y Acad Sci 1996; 786:252-63. [PMID: 8687026 DOI: 10.1111/j.1749-6632.1996.tb39068.x] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Affiliation(s)
- G Paradies
- Department of Biochemistry and Molecular Biology, University of Bari, Italy
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19
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Barile M, Passarella S, Danese G, Quagliariello E. Rat liver mitochondria can synthesize nicotinamide adenine dinucleotide from nicotinamide mononucleotide and ATP via a putative matrix nicotinamide mononucleotide adenylyltransferase. Biochem Mol Biol Int 1996; 38:297-306. [PMID: 8850525] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
In order to gain some insight into the mechanism by which nicotinamide nucleotides localize in mitochondria, NMN was added to rat liver mitochondria, with NAD synthesis tested both enzymatically and by means of HPLC. Evidence is given that the mitochondrial matrix contains a specific NMN adenylyltransferase (E.C. 2.7.7.1.), inhibited by PPi, AMP and ADP-ribose. Some features of this enzyme, including the substrate, pH and temperature dependence were also investigated.
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Affiliation(s)
- M Barile
- Dipartimento di Biochimica e Biologia Molecolare, Università di Bari, Italy
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20
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Azzariti A, Giannattasio S, Doonan S, Merafina RS, Marra E, Quagliariello E. Use of protease sensitivity to probe the conformations of newly synthesised mutant forms of mitochondrial aspartate aminotransferase. Biochem Biophys Res Commun 1995; 215:800-7. [PMID: 7488044 DOI: 10.1006/bbrc.1995.2534] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Sensitivity to digestion with pronase has been used to show that the precursor form of mitochondrial aspartate aminotransferase, the form lacking the N-terminal presequence, that with a deletion of the first 9 residues and mutants of the mature enzyme in which residue Cys-166 is mutated to alanine or serine, all retain unfolded conformations after synthesis in a reticulocyte lysate. In the presence of lysed mitochondria the various forms of mitochondrial aspartate aminotransferase retained their susceptibilities to pronase in a way that mirrored the efficiencies with which they are imported into intact mitochondria. The results are interpreted as showing that the presequence of mitochondrial aspartate aminotransferase is not uniquely required for interaction with cytosolic factors required to maintain the newly synthesised protein in a form competent for interacting with, and being imported into, mitochondria.
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Affiliation(s)
- A Azzariti
- Centro di Studio sui Mitocondri e Metabolismo Energetico-C.N.R., Bari, Italy
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21
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Paradies G, Ruggiero FM, Petrosillo G, Gadaleta MN, Quagliariello E. Carnitine-acylcarnitine translocase activity in cardiac mitochondria from aged rats: the effect of acetyl-L-carnitine. Mech Ageing Dev 1995; 84:103-12. [PMID: 8788238 DOI: 10.1016/0047-6374(95)01636-8] [Citation(s) in RCA: 45] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Age-related changes in mitochondrial fatty acids metabolism may underlie the progressive decline in cardiac function. The effect of aging and acute treatment with acetyl-L-carnitine on fatty acids oxidation and on carnitine-acylcarnitine translocase activity in rat heart mitochondria was studied. Rates of palmitoylcarnitine supported respiration as well as carnitine-carnitine and carnitine-palmitoylcarnitine exchange reactions were all depressed (approx. 35%) in heart mitochondria from aged rats. These effects were almost completely reversed following treatment of aged rats with acetyl-L-carnitine. Heart mitochondrial cardiolipin content was significantly reduced (approx. 38%) in aged rats. Treatment of aged rats with acetyl-L-carnitine restored the level of cardiolipin to that of young rats. It is suggested that acetyl-L-carnitine is able to reverse age-related decrement in mitochondrial carnitine-acylcarnitine exchange activity by restoring the normal cardiolipin content.
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Affiliation(s)
- G Paradies
- Department of Biochemistry and Molecular Biology, University of Bari, Italy
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22
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Marra E, Azzariti A, Giannattasio S, Doonan S, Quagliariello E. Cumulative effects of mutations in newly synthesised mitochondrial aspartate aminotransferase on uptake into mitochondria. Biochem Biophys Res Commun 1995; 214:511-7. [PMID: 7677759 DOI: 10.1006/bbrc.1995.2316] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Mutant genes were constructed which coded for the precursor form of mitochondrial aspartate aminotransferase in which residue cysteine 166 was mutated to either serine or alanine and for forms of the protein lacking both the presequence and residues 1-9 of the mature protein but carrying the same cysteine mutations. The protein products of all of these mutant genes were imported into mitochondria that had been added to the expression system but with varying degrees of efficiency. The results showed that the effects of mutation of cysteine 166 and of deletion of residues 1-9 of the mature protein on sequestration into mitochondria were essentially cumulative, suggesting that these parts of the protein are involved in distinct steps on the recognition/uptake pathway.
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Affiliation(s)
- E Marra
- Centro di Studio sui Mitocondri e Metabolismo Energetico, C.N.R., Bari, Italy
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23
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Riccio P, Giovannelli S, Bobba A, Romito E, Fasano A, Bleve-Zacheo T, Favilla R, Quagliariello E, Cavatorta P. Specificity of zinc binding to myelin basic protein. Neurochem Res 1995; 20:1107-13. [PMID: 8570016 DOI: 10.1007/bf00995566] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Zn2+ appears to stabilize the myelin sheath but the mechanism of this effect is unknown. In a previous report we have shown that zinc binds to CNS myelin basic protein (MBP) in the presence of phosphate and this results in MBP aggregation. For this paper we used a solid phase zinc blotting assay to identify which myelin proteins bind zinc. MBP and a 58 kDa band were found to be the major targets of 65Zn binding. Moreover, using fluorescence, light scattering and electron microscopy we investigated the binding of zinc and other cations to purified MBP in solution. Among the cations tested for their ability to interfere with the binding of zinc, the most effective were cadmium, mercury and copper, but only cadmium and mercury increased the scattering intensity, whereas MBP aggregation was not inhibited by copper ions. Thus, the effect of zinc on the formation of MBP clusters seems to be specific.
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Affiliation(s)
- P Riccio
- Dept. of Biology, Defence and A.F. Technology, University of Basilicata, Potenza, Italy
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24
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Megli FM, Selvaggi M, De Lisi A, Quagliariello E. EPR study of annexin V-cardiolipin Ca-mediated interaction in phospholipid vesicles and isolated mitochondria. Biochim Biophys Acta 1995; 1236:273-8. [PMID: 7794966 DOI: 10.1016/0005-2736(95)00057-a] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
The properties of the binding of annexin V to variously composed phospholipid vesicles have been studied by applying a recently developed EPR method, using an annexin V spin label. By this approach, this protein is seen to bind to acidic phospholipid-containing vesicles, as reported, thus confirming the reliability of the method. In addition, binding of this annexin to cardiolipin-containing vesicles has been studied in more depth, and the protein has been shown to have a distinct affinity for this phospholipid. As a cardiolipin-rich natural membrane system, mitochondrial membranes and mitoplasts from rat liver were considered, and a strong binding of AV to these membranes was observed. Having compared this binding with that to phospholipid vesicles, cardiolipin-rich microdomains in the mitochondrial membranes are proposed as the putative mitochondrial binding sites for annexin V.
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Affiliation(s)
- F M Megli
- Centro di Studio sui Mitocondri e Metabolismo Energetico, CNR, Università di Bari, Italy
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25
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Abstract
Glutamine transport in both normal and acidotic rat kidney mitochondria was investigated using both isotopic techniques and by spectroscopic measurements in which glutamine metabolism was allowed to occur. Widely used criteria for demonstrating the occurrence of carrier-mediated transport were successfully applied in both cases. Three transport mechanisms were found to occur, namely glutamine uniport, active only during acidosis and glutamine/glutamate and glutamine/malate antiports, active in both normal and acidotic mitochondria. Efflux of glutamate, via a glutamate/OH- translocator, following glutamine uptake by mitochondria was experimentally ruled out. Glutamine uniport in acidotic mitochondria and glutamine/glutamate and glutamine/malate antiports in both normal and acidotic mitochondria were investigated in detail: differences found in Km and Vmax values, in pH and temperature dependence, and in the pattern of inhibitor sensitivity of glutamine transport demonstrated the existence of five different translocators whose activities were found to fit with the physiological requirements of renal ammoniogenesis.
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Affiliation(s)
- A Atlante
- Centro di Studio sui Mitocondri e Metabolismo Energetico, CNR, Bari, Italy
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26
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Perlino E, Maenza S, Marra E, Ciampolillo A, Marra G, Derobertis O, Giorgino R, Quagliariello E. Ttf1 gene-expression in human proliferating thyroid-diseases. Oncol Rep 1994; 1:1097-100. [PMID: 21607498 DOI: 10.3892/or.1.6.1097] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
TTF1 mRNA expression in the thyroid gland from 30 patients with thyroid proliferating diseases and 4 healthy donors used as normal controls was investigated using Northern blot analysis. Six patients affected by malignant thyroid carcinomas and six patients with adenoma were examined; moreover 18 patients with non malignant proliferating disease such as multinodular goiters were investigated. Determination of TTF1 mRNA revealed a significant decrease of the steady state mRNA levels in carcinomas and adenomas as compared to normal tissues. On the contrary, in patients affected by multinodular goiters variations were observed that seemed not to be directly associated with the pathological conditions.
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Affiliation(s)
- E Perlino
- UNIV BARI,DEPT BIOCHEM & MOLEC BIOL,BARI,ITALY. UNIV BARI,INST MED ENDOCRINOL & METAB DIS,BARI,ITALY. GB MORGAGNI L PIERANTONI HOSP,DIV GEN SURG,FORLI,ITALY
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27
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Barile M, Valenti D, Hobbs GA, Abruzzese MF, Keilbaugh SA, Passarella S, Quagliariello E, Simpson MV. Mechanisms of toxicity of 3'-azido-3'-deoxythymidine. Its interaction with adenylate kinase. Biochem Pharmacol 1994; 48:1405-12. [PMID: 7945440 DOI: 10.1016/0006-2952(94)90564-9] [Citation(s) in RCA: 51] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Recent experiments from our laboratory have indicated that the inhibitory effect of 3'-azido-3'-deoxythymidine (AZT) on oxidative phosphorylation may occur directly, in addition to being brought about by its inhibition of mtDNA replication. We report here studies on the effect of AZT on adenylate kinase, an enzyme crucial to oxidative phosphorylation. AZT decreased the aromatic residues fluorescence of rabbit muscle adenylate kinase, indicating binding of AZT to the enzyme. Of three other enzymes studied as controls, AZT bound only to those that possessed ATP/ADP binding sites. Up to concentrations of 15 microM, AZT was a more potent effector of fluorescence quenching than were ATP, ADP, AMP, and the AZT control, deoxythymidine. AZT strongly inhibited adenylate kinase in the direction of ATP synthesis (Ki, 8 microM), the inhibition being of the partial competitive type, whereas deoxythymidine inhibition, also partially competitive, was much weaker (Ki, 90 microM). When measured in the direction of ADP synthesis, AZT failed to demonstrate any inhibition at concentrations up to 10 microM. Experiments on isolated intact rat liver mitochondria with the enzyme activity measured in both directions confirmed the isolated enzyme results. Respiratory control by these mitochondria was not affected by AZT. The finding of AZT affinity for ATP/ADP binding sites may open new avenues of approach to the study of AZT toxicity.
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Affiliation(s)
- M Barile
- Dipartimento di Biochimica e Biologia Molecolare, Università degli Studi, Bari, Italy
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28
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Vacca RA, Marra E, Quagliariello E, Greco M. Increase of both transcription and translation activities following separate irradiation of the in vitro system components with He-Ne laser. Biochem Biophys Res Commun 1994; 203:991-7. [PMID: 8093085 DOI: 10.1006/bbrc.1994.2280] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
To gain insight into the mechanism by which cell irradiation with low power continuous wave He-Ne laser (632.8 nm) causes a general stimulation of biosynthetic properties, separate components of transcription and translation systems were irradiated (energy dose 2 Joules/cm2; laser power 12 mW) with measurements made of in vitro RNA and protein synthesis. In addition, all tested components were investigated with respect to influence of laser irradiation on their conformation, as spectroscopically monitored. In all cases an increase in both transcription and translation activities was found with a significant change in absorbance/fluorescence spectra.
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Affiliation(s)
- R A Vacca
- Dipartimento di Biochimica e Biologia Molecolare, Università di Bari, Italy
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29
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Paradies G, Ruggiero FM, Petrosillo G, Gadaleta MN, Quagliariello E. Effect of aging and acetyl-L-carnitine on the activity of cytochrome oxidase and adenine nucleotide translocase in rat heart mitochondria. FEBS Lett 1994; 350:213-5. [PMID: 8070566 DOI: 10.1016/0014-5793(94)00763-2] [Citation(s) in RCA: 81] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
The effect of aging and treatment with acetyl-L-carnitine on the activity of cytochrome oxidase and adenine nucleotide translocase in rat heart mitochondria was studied. It was found that the activity of both these mitochondrial protein systems was reduced (by around 30%) in aged animals. Treatment of aged rats with acetyl-L-carnitine almost completely reversed this effect. Changes in the mitochondrial cardiolipin content appear to be responsible for these effects of acetyl-L-carnitine.
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Affiliation(s)
- G Paradies
- Department of Biochemistry and Molecular Biology, University of Bari, Italy
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30
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Abstract
Hydroxyproline uptake by rat kidney mitochondria is here first shown by monitoring the reduction of the intramitochondrial pyridine nucleotides which occurs as a result of metabolism of imported hydroxyproline via hydroxyproline oxidase and 3-hydroxy-pyrroline-5-carboxylate dehydrogenase. Widely used criteria for demonstrating the occurrence of carrier-mediated transport were applied to this process. Hydroxyproline uptake shows saturation features (Km and Vmax values, measured at 20 degrees C and at pH 7.20, were found to be about 1.4 mM and 5 nmoles/min x mg mitochondrial protein, respectively) and proves to be inhibited by the impermeable compound phenylsuccinate, but insensitive to externally added methylglutamate. Difference found in the Km and Vmax values, a different inhibitor sensitivity and the failure of hydroxyproline to cause efflux of glutamate from the mitochondria show that hydroxyproline enters mitochondria by means of a translocator different from those which transport proline.
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Affiliation(s)
- A Atlante
- Centro di Studio sui Mitocondri e Metabolismo Energetico, C.N.R., Bari, Italy
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31
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Giannattasio S, Azzariti A, Marra E, Quagliariello E. The N-terminal region of mature mitochondrial aspartate aminotransferase can direct cytosolic dihydrofolate reductase into mitochondria in vitro. Biochem Biophys Res Commun 1994; 201:1059-65. [PMID: 8024546 DOI: 10.1006/bbrc.1994.1812] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Two fused genes were constructed which encode for two chimeric proteins in which either 10 or 191 N-terminal amino acids of mature mitochondrial aspartate aminotransferase had been attached to the entire polypeptide chain of cytosolic dihydrofolate reductase. The precursor and mature form of mitochondrial aspartate aminotransferase, dihydrofolate reductase and both chimeric proteins were synthesized in vitro and their import into isolated mitochondria was studied. Both chimeric proteins were taken up by isolated organelles, where they became protease resistant, thus indicating the ability of the N-terminal portion of the mature moiety of the precursor of mitochondrial aspartate aminotransferase to direct cytosolic dihydrofolate reductase into mitochondria.
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Affiliation(s)
- S Giannattasio
- Centro di Studio sui Mitocondri e Metabolismo Energetico, C.N.R., Bari, Italy
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32
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Paradies G, Ruggiero FM, Petrosillo G, Gadaleta MN, Quagliariello E. The effect of aging and acetyl-L-carnitine on the function and on the lipid composition of rat heart mitochondria. Ann N Y Acad Sci 1994; 717:233-43. [PMID: 8030840 DOI: 10.1111/j.1749-6632.1994.tb12093.x] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Affiliation(s)
- G Paradies
- Department of Biochemistry and Molecular Biology, University of Bari, Italy
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33
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Cavatorta P, Giovanelli S, Bobba A, Riccio P, Szabo AG, Quagliariello E. Myelin basic protein interaction with zinc and phosphate: fluorescence studies on the water-soluble form of the protein. Biophys J 1994; 66:1174-9. [PMID: 7518704 PMCID: PMC1275824 DOI: 10.1016/s0006-3495(94)80899-9] [Citation(s) in RCA: 28] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
The interaction of myelin basic protein (MBP) with zinc and phosphate ions has been studied by using the emission properties of the single tryptophan residue of the protein (Trp-115). The studies have been carried out by means of both static and time-resolved fluorescence techniques. The addition of either zinc to MBP in the presence of phosphate or phosphate to MBP in the presence of zinc resulted in an increase of fluorescence intensity and a blue shift of the emission maximum wavelength. Furthermore, a concomitant increase in the scattering was also detected. Anisotropy decay experiments demonstrated that these effects are due to the formation of MBP molecules into large aggregates. A possible physiological role for such interaction is discussed.
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Affiliation(s)
- P Cavatorta
- Dipartimento di Fisica, Sezione di Biofisica, Università di Parma, Italy
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34
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Abstract
We have previously shown that CNS myelin basic protein (MBP) can be purified in the lipid-bound, native-like form by using a procedure based on myelin solubilization with detergents at pH above 7, and on the filter-like use of hydroxyapatite to separate non-adsorbed MBP from other myelin proteins. Here, we report on the isolation of MBP in the zwitterionic detergent 3-((3-cholamidopropyl)dimethylammonio)-1-propane sulfonate (CHAPS), which does not interfere at 280 nm and can be removed by dialysis. This detergent appears to improve MBP purification and to be suitable for fluorescence and reconstitution studies that can be useful to understand both structure and function of MBP in its natural environment.
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Affiliation(s)
- P Riccio
- Department of Biochemistry and Molecular Biology, University of Bari, Italy
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35
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Abstract
Proline transport in rat kidney mitochondria was investigated both by using isotopic techniques and by spectroscopic measurements, in which proline metabolism was essentially allowed to occur. Widely used criteria for demonstrating the occurrence of carrier-mediated transport were successfully applied in both cases. Differences found in the Km and Vmax values, in pH and temperature dependence of proline transport, and in the inhibitor sensitivity demonstrate the existence of two separate translocators for proline in rat kidney mitochondria, i.e., the proline uniporter and the proline/glutamate antiporter. Efflux of glutamate via glutamate/OH- translocator following proline uptake by mitochondria was experimentally ruled out. Discussion is also made of the possible role of such translocators in proline metabolism and in the putative proline/glutamate shuttle.
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Affiliation(s)
- A Atlante
- Centro di Studio sui Mitocondri e Metabolismo Energetico-CNR, Bari, Italy
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36
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Paradies G, Ruggiero FM, Petrosillo G, Quagliariello E. Enhanced cytochrome oxidase activity and modification of lipids in heart mitochondria from hyperthyroid rats. Biochim Biophys Acta 1994; 1225:165-70. [PMID: 8280784 DOI: 10.1016/0925-4439(94)90074-4] [Citation(s) in RCA: 60] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
In order to further investigate the mechanism regulating the control of mitochondrial respiration by thyroid hormones, the effect of the hyperthyroidism on the kinetic characteristics of cytochrome c oxidase in rat heart mitochondria was studied. Mitochondrial preparations from both control and hyperthyroid rats had equivalent Km values for cytochrome c, while the maximal activity of cytochrome oxidase was significantly increased (by around 30%) in mitochondrial preparation from hyperthyroid rats. This enhanced activity of cytochrome oxidase was associated to a parallel increase in mitochondrial State 3 respiration. The hormone treatment resulted in a decrease in the flux control coefficient of the oxidase. The enhanced activity of cytochrome oxidase in hyperthyroid rats does not appear to be dependent on an increase in the mass of this enzyme complex in that the heme aa3 content was equivalent in both hyperthyroid and control preparations. The Arrhenius plot characteristics differ for cytochrome oxidase activity in mitochondria from hyperthyroid rats as compared with control rats in that the breakpoint of the biphasic plot is shifted to a lower temperature. Cardiolipin content was significantly increased in mitochondrial preparations from hyperthyroid rats, while there were no significant alterations in the fatty acid composition of cardiolipin of control and hyperthyroid preparations. The results support the conclusion that the enhanced cytochrome oxidase activity in heart mitochondrial preparations from hyperthyroid rats is due to a specific increase in the content of cardiolipin.
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Affiliation(s)
- G Paradies
- Department of Biochemistry and Molecular Biology, University of Bari, Italy
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37
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Perlino E, Marra E, Maenza S, de Terlizzi M, Coppola BC, Santostasi T, Quagliariello E. Lactate dehydrogenase isoenzyme patterns in blood cells from histiocytosis X children. Clin Chim Acta 1993; 223:83-91. [PMID: 8143371 DOI: 10.1016/0009-8981(93)90064-b] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
To find a clinical assay for histiocytosis X (HX) diagnosis, measurements were made of both activity and isoenzyme distribution of lactate dehydrogenase (LDH; EC 1.1.1.27) from the blood cells of 6 acute phase and 9 remission patients. A significant increase in the LDH activity measured in the monocytes and lymphocytes isolated from the blood of the acute phase patients was found. The increased activity was due to an enhancement of the normal pattern of LDH isoenzymes in these cells and not to a change in isoenzyme distribution. No increase was found in monocyte LDH isoenzymes from the patients in remission.
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Affiliation(s)
- E Perlino
- Centro di Studio sui Mitocondri e Metabolismo Energetico, C.N.R., Bari, Italy
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38
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Paradies G, Ruggiero FM, Dinoi P, Petrosillo G, Quagliariello E. Decreased cytochrome oxidase activity and changes in phospholipids in heart mitochondria from hypothyroid rats. Arch Biochem Biophys 1993; 307:91-5. [PMID: 8239670 DOI: 10.1006/abbi.1993.1565] [Citation(s) in RCA: 61] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
The effect of hypothyroidism on kinetic characteristics of cytochrome oxidase in rat heart mitochondria was studied. Mitochondrial preparations from control and hypothyroid rats had equivalent Km values for cytochrome c, while the maximal activity of the oxidase was significantly decreased (more than 30%) in mitochondrial preparations from hypothyroid rats. This decrease is associated to a parallel decrease in state 3 respiration. The cytochrome aa3 content was slightly decreased (by around 15%) in mitochondria from hypothyroid rats. The Arrhenius plot characteristics differ for cytochrome oxidase activity in mitochondria from hypothyroid rats as compared with control rats in that the breakpoint of the biphasic plot is shifted to a higher temperature. Cardiolipin content was markedly decreased in the mitochondrial membrane from hypothyroid rats. No alterations were found in the pattern of cardiolipin fatty acid distribution of mitochondrial membrane from control and hypothyroid rats. The effects of the hypothyroid state on the activity of cytochrome oxidase, on cytochrome aa3 levels, and on cardiolipin contents were completely reversed by following the treatment of hypothyroid rats with thyroid hormone. The results support the conclusion that the depressed mitochondrial cytochrome oxidase activity in the hypothyroid state is due, at least in part, to a decrease in the cardiolipin content of the mitochondrial inner membrane.
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Affiliation(s)
- G Paradies
- Dipartimento di Biochimica e Biologia Molecolare, Università degli Studi di Bari, Italy
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39
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Abstract
To gain some insight into the mechanism by which red light-biosystem interaction occurs, an investigation was made of certain features of purified glutamate dehydrogenase from beef liver (E.C. 1.4.1.3.) irradiated with either an He-Ne laser (632.8 nm) or a red light-emitting diode (650 +/- 20 nm). In both cases the energy dose was 0.24 J cm-2. Significant changes in the glutamate dehydrogenase extinction coefficient measured at 275 nm, the capability of the enzyme to bind the reduced form of nicotinamide adenine dinucleotide (NADH), certain kinetic parameters, the pH and temperature dependence and the sensitivity to guanosine 5 triphosphate (GTP) and adenosine diphosphate (ADP) were found, probably due to the interaction of light with a protein domain containing a metal ion or ions. He-Ne laser and diode irradiation were found to differ with regard to their interaction with glutamate dehydrogenase. Interestingly, different effects were also found when an He-Ne laser and a non-coherent Xe-Hg lamp were used to irradiate glutamate dehydrogenase under the same experimental conditions. This confirms that non-coherent light at various power levels affects the isolated glutamate dehydrogenase.
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Affiliation(s)
- A Ostuni
- Dipartimento di Biochimica e Biologia Molecolare, Università di Bari, Italy
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40
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Abstract
To gain further insight into the effect of He-Ne laser irradiation on the mitochondrial biosynthetic apparatus, DNA synthesis was measured in mitochondria, mitoplasts and mitochondrial matrix fraction irradiated with low power continuous wave He-Ne laser (energy dose 5 Joules/cm2; laser power 12 mW). As a result of irradiation, the amount of alpha-[32P]dATP incorporated in acid insoluble materials was found to increase. Electrophoretic analysis of in vitro synthesised DNA purified from mitochondria, mitoplasts and matrix fraction shows an increase of 50-60% of DNA synthesis in the irradiated samples. These data show that He-Ne laser stimulates the replication of mitochondrial DNA in both intact organelles and soluble matrix fraction, thus suggesting an interaction of laser light with matrix soluble molecule/s.
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Affiliation(s)
- R A Vacca
- Centro di Studio sui Mitocondrie e Metabolismo Energetico, C.N.R. Bari, Italy
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Barile M, Passarella S, Bertoldi A, Quagliariello E. Flavin adenine dinucleotide synthesis in isolated rat liver mitochondria caused by imported flavin mononucleotide. Arch Biochem Biophys 1993; 305:442-7. [PMID: 8373181 DOI: 10.1006/abbi.1993.1444] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
Evidence is given in this paper that externally added flavin mononucleotide (FMN) induces flavin adenine dinucleotide synthesis in isolated rat liver mitochondria, as shown by fluorimetric, chromatographic, and enzymatic assays. FMN association with mitochondria is a process with hyperbolic features that is sensitive to externally added mersalyl.
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Affiliation(s)
- M Barile
- Dipartimento di Biochimica e Biologia Molecolare, Università di Bari, Italy
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Paradies G, Ruggiero FM, Petrosillo G, Quagliariello E. Age-dependent decrease in the cytochrome c oxidase activity and changes in phospholipids in rat-heart mitochondria. Arch Gerontol Geriatr 1993; 16:263-72. [PMID: 15374339 DOI: 10.1016/0167-4943(93)90037-i] [Citation(s) in RCA: 52] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/1993] [Revised: 05/03/1993] [Accepted: 05/04/1993] [Indexed: 10/27/2022]
Abstract
The effect of aging on the kinetic characteristics of cytochrome c oxidase in rat heart mitochondria was investigated. Mitochondria from young and aged rats had equivalent Km values for cytochrome c, while the maximal activity of the oxidase was significantly reduced in mitochondria from aged rats. The cytochrome aa3 content was the same in both these two types of mitochondria. The Arrhenius plot characteristics differ for cytochrome oxidase activity in mitochondria from aged rats as compared with young rats in that the breakpoint of the biphasic plot was shifted to a higher temperature. Cardiolipin content was markedly decreased in mitochondrial membrane from aged rats. No alterations were found in the patterns of the phospholipid fatty acid distribution of mitochondrial membranes from young and aged rats. The results support the conclusion that the reduced mitochondrial cytochrome c oxidase activity in aged animals is due to a specific decrease in the cardiolipin content.
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Affiliation(s)
- G Paradies
- Department of Biochemistry and Molecular Biology and C.N.R. Unit for the Study of Mitochondria and Bioenergetics, Bari, Italy
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Paradies G, Ruggiero FM, Quagliariello E. Age-dependent changes in the activity of anion carriers and in the lipid composition in rat heart mitochondria. Ann N Y Acad Sci 1992; 673:160-4. [PMID: 1485714 DOI: 10.1111/j.1749-6632.1992.tb27448.x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Affiliation(s)
- G Paradies
- Department of Biochemistry and Molecular Biology, University of Bari, Italy
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Giannattasio S, Marra E, Vacca RA, Iannace G, Quagliariello E. Import of mutant forms of mitochondrial aspartate aminotransferase into isolated mitochondria. Arch Biochem Biophys 1992; 298:532-7. [PMID: 1416982 DOI: 10.1016/0003-9861(92)90446-4] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
To gain some insight into the role played by certain protein domains in the import of mitochondrial aspartate aminotransferase in isolated mitochondria, three protein mutants were constructed by using the plasmid pOTS-mAspAT, which contains the nucleotide sequence encoding for the mature form of this enzyme. Two mutant proteins in which Cys-166 was substituted with either serine or alanine and another protein lacking the nine N-terminal amino acids were all synthesized in a cell-free transcription/translation system. Comparison was made among the newly synthesized mutant proteins and the newly synthesized wild type aspartate aminotransferase with respect to their capability to enter mitochondria. All the mutant proteins proved to be able to enter mitochondria even though with a lower efficiency than the wild type enzyme. Interestingly the thiol reagent mersalyl proved to inhibit import of both wild type enzyme and serine mutant, whereas import of alanine mutant was found to be insensitive to mersalyl, thus showing that Cys-166 is the unique -SH group involved in import. Import of mitochondrial aspartate aminotransferase by mitochondria is shown to involve certain protein domains present in the mature protein, two of them being the Cys-166 and the N-terminal regions.
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Affiliation(s)
- S Giannattasio
- C.N.R. Centro di Studio sui Mitocondri e Metabolismo Energetico, Bari, Italy
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Ruggiero FM, Cafagna F, Petruzzella V, Gadaleta MN, Quagliariello E. Lipid composition in synaptic and nonsynaptic mitochondria from rat brains and effect of aging. J Neurochem 1992; 59:487-91. [PMID: 1629722 DOI: 10.1111/j.1471-4159.1992.tb09396.x] [Citation(s) in RCA: 55] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
The cholesterol, phospholipid, and fatty acid compositions in synaptic and nonsynaptic mitochondria from rat brains and the effect of aging were studied. Both cholesterol and phospholipid contents were found to be significantly different in synaptic compared to nonsynaptic mitochondria. In both types of brain mitochondria, aging decreases the cholesterol content by 27% and the phospholipid content by approximately 12%. The difference between these decreases observed in the organelles causes decreases in the cholesterol/phospholipid molar ratios for synaptic and nonsynaptic mitochondria of 17 and 19%, respectively. Also, the phospholipid composition is significantly different in synaptic compared to nonsynaptic mitochondria. Among phospholipids, only the cardiolipin fraction showed a significant decrease (26%) in nonsynaptic mitochondria from the brains of aged rats. Instead, the fatty acid composition was not significantly different in synaptic compared to nonsynaptic mitochondria. The 21% aging decrease in linoleic acid (18:2), observed only in nonsynaptic mitochondria, may be related to a decrease in cardiolipin, which contains a large amount of this fatty acid.
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Affiliation(s)
- F M Ruggiero
- Department of Biochemistry and Molecular Biology, University of Bari, Italy
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Abstract
Sodium chloride extracts obtained from purified bovine brain myelin were found to contain proteolytic activity capable of degrading isolated myelin basic protein as assessed by SDS gel electrophoresis. Using gels copolymerized with gelatin as substrate, two bands at about 54 and 117-125 KDa, respectively, were detected. Activity corresponding to the 54 KDa band was inhibited by zinc. Data presented in this article suggest that proteolytic activity can be released from the myelin sheath in water-soluble form and recognize MBP as substrate.
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Affiliation(s)
- G M Liuzzi
- Dipartimento di Biochimica e Biologia Molecolare, Universita di Bari, Italy
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Kanduc D, Aresta A, Quagliariello E, Farber E. Effect of MNU on the methylation pattern of hepatic DNA during compensatory cell proliferation. Biochem Biophys Res Commun 1992; 184:107-11. [PMID: 1567416 DOI: 10.1016/0006-291x(92)91164-l] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
We have used the initiation-promotion model of MNU-induced hepatocarcinogenesis to test the hypothesis that alteration of the methylation status of DNA cytosines could be involved in the initiation of carcinogenesis. In fact cell proliferation plays a fundamental role in the initiation of liver carcinogenesis and hepatocytes in the S phase are more sensitive towards MNU initiation than at other times in the cycle. The molecular mechanisms involved in these processes, however, are still poorly understood and it seemed of value to monitor the DNA methylation status in this system. The results obtained indicate that MNU hepatocarcinogenic action might consist also of the inhibition of DNA hypomethylation biologically associated with cell proliferation.
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Affiliation(s)
- D Kanduc
- Dept. of Biochemistry and Molecular Biology, Faculty of Science, University of Bari, Italy
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Paradies G, Ruggiero FM, Gadaleta MN, Quagliariello E. The effect of aging and acetyl-L-carnitine on the activity of the phosphate carrier and on the phospholipid composition in rat heart mitochondria. Biochim Biophys Acta 1992; 1103:324-6. [PMID: 1543717 DOI: 10.1016/0005-2736(92)90103-s] [Citation(s) in RCA: 98] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
The effect of aging and treatment with acetyl-L-carnitine on the activity of the phosphate carrier and on the phospholipid composition in rat heart mitochondria was studied. It was found that the activity of the phosphate carrier was reduced by aging. Treatment of aged rats with acetyl-L-carnitine reversed this effect. The mitochondrial level of cardiolipin was decreased with aging. Treatment of aged rats with acetyl-L-carnitine restored the level of cardiolipin to that of young rats. It is proposed that acetyl-L-carnitine may restore the correct phospholipid composition (cardiolipin level) of the mitochondrial membrane, altered by aging, thereby restoring the activity of the phosphate carrier.
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Affiliation(s)
- G Paradies
- Department of Biochemistry and Molecular Biology, University of Bari, Italy
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Abstract
To gain some insight into the process by which both acetylCoA and NADPH, needed for fatty acid synthesis, are obtained, in the cytosol, from the effluxed intramitochondrial citrate, via citrate lyase and malate dehydrogenase plus malic enzyme respectively, the capability of externally added pyruvate to cause efflux of malate from rat liver mitochondria was tested. The occurrence of a pyruvate/malate translocator is here shown: pyruvate/malate exchange shows saturation features (Km and Vmax values, measured at 20 degrees C and at pH 7.20, were found to be about 0.25 mM and 2.7 nmoles/min x mg mitochondrial protein, respectively) and is inhibited by certain impermeable compounds. This carrier, together with the previously reported tricarboxylate and oxodicarboxylate translocators proved to allow for citrate and oxaloacetate efflux due to externally added pyruvate.
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Affiliation(s)
- A Atlante
- Centro di Studio sui Mitocondri e Metabolismo Energetico, CNR, Bari, Italy
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