[45] Cytochrome oxidase from beef heart mitochondria

Wharton, David C.; Tzagoloff, Alexander

doi:10.1016/0076-6879(67)10048-7

Cited by 1,135 publications

(475 citation statements)

References 11 publications

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“…The rate of oxidation of cytochrome c was measured by following the decrease in the absorbance of its a-band at 550 nm [31]. The standard reaction mixture containing 10 mM phosphate buffer (pH 7.0) plus 14% ferrocytochrome c and the absorbance change at 550 nm was measured at 37°C, in the absence or in the presence of vanadate, after addition of 200 lg mitochondria protein per ml.…”

Section: Mitochondrial Enzyme Activitiesmentioning

confidence: 99%

Decavanadate induces mitochondrial membrane depolarization and inhibits oxygen consumption

Soares¹,

Gutiérrez‐Merino²,

Aureliano³

2007

Journal of Inorganic Biochemistry

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Decavanadate induced rat liver mitochondrial depolarization at very low concentrations, half-depolarization with 39 nM decavanadate, while it was needed a 130-fold higher concentration of monomeric vanadate (5 lM) to induce the same effect. Decavanadate also inhibits mitochondrial repolarization induced by reduced glutathione in vitro, with an inhibition constant of 1 lM, whereas no effect was observed up to 100 lM of monomeric vanadate. The oxygen consumption by mitochondria is also inhibited by lower decavanadate than monomeric vanadate concentrations, i.e. 50% inhibition is attained with 99 nM decavanadate and 10 lM monomeric vanadate. Thus, decavanadate is stronger as mitochondrial depolarization agent than as inhibitor of mitochondrial oxygen consumption. Up to 5 lM, decavanadate does not alter mitochondrial NADH levels nor inhibit neither F O F 1 -ATPase nor cytochrome c oxidase activity, but it induces changes in the redox steady-state of mitochondrial b-type cytochromes (complex III). NMR spectra showed that decameric vanadate is the predominant vanadate species in decavanadate solutions. It is concluded that decavanadate is much more potent mitochondrial depolarization agent and a more potent inhibitor of mitochondrial oxygen consumption than monomeric vanadate, pointing out the importance to take into account the contribution of higher oligomeric species of vanadium for the biological effects of vanadate solutions.

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Section: Mitochondrial Enzyme Activitiesmentioning

confidence: 99%

Decavanadate induces mitochondrial membrane depolarization and inhibits oxygen consumption

Soares¹,

Gutiérrez‐Merino²,

Aureliano³

2007

Journal of Inorganic Biochemistry

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“…Such approaches have been made by a variety of workers; in [13] dialysis against cyanide or treatment with batho-cuproin-sulfonate under acidic conditions, promoted a significant removal of the copper. In the copper-depleted preparation, both the absorbance at 830 nm and the EPR signal attributed to detectable copper are diminished, as indeed is the catalytic activity.…”

Section: Introductionmentioning

confidence: 99%

Structural features of the copper‐depleted cytochrome oxidase from beef heart: iron exafs

Powers¹,

Chance

Ching³

et al. 1982

FEBS Letters

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“…The quality of the mitochondria was monitored by assaying the activity and accessibility of cytochrome c oxidase, a component of the inner membrane of the organelle (30). Nearly all of the cytochrome oxidase activity was recovered in purified mitochondria (Fig.…”

Section: S-akap84 Is Targeted To the Outer Membrane Ofmentioning

confidence: 99%

“…Highly purified mitochondria were isolated by differential centrifugation and sedimentation through a Percoll gradient as described by Hovias et al (29). Cytochrome c oxidase activity was determined spectrophotometrically by following the decrease in cytochrome c absorbance at 550 nm (30).…”

Section: Isolation Of Cdnas Encoding Mouse S-akap84 Isoforms-comple-mentioning

confidence: 99%

Organelle-specific Targeting of Protein Kinase AII (PKAII)

Chen

Lin

Rubin

1997

Journal of Biological Chemistry

132

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Experiments were designed to test the idea that A kinase anchor proteins (AKAPs) tether regulatory subunits (RII) of protein kinase AII (PKAII) isoforms to surfaces of organelles that are bounded by phospholipid bilayers. S-AKAP84, one of three RII-binding proteins encoded by a single-copy murine gene, was studied as a prototypic organelle-associated AKAP. When S-AKAP84 was expressed in HEK293 cells, the anchor protein was targeted to mitochondria and excluded from other cell compartments. The RII tethering site is located in the cytoplasm adjacent to the mitochondrial surface. Endogenous RII subunits are not associated with mitochondria isolated from control cells. Expression of S-AKAP84 in transfected HEK293 cells triggered a redistribution of 15% of total RII to mitochondria. Thus, the tethering region of the organelle-inserted anchor protein is properly oriented and avidly binds RII (PKAII) isoforms in intact cells. Two critical domains in S-AKAP84 were mapped. Residues 1 to 30 govern insertion of the polypeptide into the outer mitochondrial membrane; amino acids 306 -325 constitute the RII-binding site. Properties established for S-AKAP84 in vitro and in situ strongly suggest that a physiological function of this protein is to concentrate and immobilize RII (PKAII) isoforms at the cytoplasmic face of a phospholipid bilayer.Type II isoforms of cAMP-dependent protein kinase (PKAII␣ and PKAII␤) 1 are attached to cytoskeleton or organelles via binding of their regulatory subunits (RII␣, RII␤) with protein kinase A anchor proteins (AKAPs) (1-3). Prototypic neuronal anchor proteins (bovine AKAP75 and its human (AKAP79) and rat (AKAP150) homologs) have a conserved binding site for RII subunits and domains that non-covalently link AKAP⅐PKAII complexes to the dendritic cytoskeleton of neurons and the cortical actin cytoskeleton of non-neuronal cells (4 -9). Both cytoskeletal locations are closely apposed to the plasma membrane. Therefore, anchored PKAII is placed in proximity with a signal generator (hormone/neurotransmitter-activated adenylate cyclase) and multiple PKA substrate/effector proteins (e.g. myosin light chain kinase, microtubule-associated protein-2, ion channels, serpentine receptors that couple with the GTPbinding protein Gs). This arrangement creates a target site for cAMP action (reviewed in Ref. 1).Distinct RII-binding proteins mediate association of PKAII isoforms with peroxisomes, mitochondria, and other organelles in a variety of cell types (1, 2, 10, 11). These AKAPs have 20-residue RII-binding sites that are homologous with the RIIbinding domain in AKAP75 (1, 2, 6, 10, 11). Otherwise, sequences of non-neuronal AKAPs diverge among themselves and differ from the sequence of AKAP75. Potential targeting domains for some non-neuronal AKAPs have been inferred from motifs in derived amino acid sequences and the distribution of the anchor proteins observed upon subcellular fractionation and immunostaining (1, 2, 10, 11). However, an experimental demonstration that an anchor protein governs accumulatio...

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[45] Cytochrome oxidase from beef heart mitochondria

Cited by 1,135 publications

References 11 publications

Decavanadate induces mitochondrial membrane depolarization and inhibits oxygen consumption

Decavanadate induces mitochondrial membrane depolarization and inhibits oxygen consumption

Structural features of the copper‐depleted cytochrome oxidase from beef heart: iron exafs

Organelle-specific Targeting of Protein Kinase AII (PKAII)

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