ESEEM studies of the iron-sulphur clusters of succinate dehydrogenase in Arum maculatum spadix mitochondrial membranes

1994 ◽  
Vol 1185 (1) ◽  
pp. 43-49 ◽  
Author(s):  
Jasvinder K. Shergill ◽  
Richard Cammack
Keyword(s):  
Succinate Dehydrogenase ◽  
Mitochondrial Membranes ◽  
Arum Maculatum

Ultrastructural localization of succinate dehydrogenase in a self-parasitic isolate of Saprolegnia megasperma

1977 ◽  
Vol 23 (5) ◽  
pp. 491-496
Author(s):  
Sharon Faye Murrin ◽  
Richard A. Nolan
Keyword(s):  
Electron Microscopy ◽  
Succinate Dehydrogenase ◽  
Cell Walls ◽  
Ultrastructural Localization ◽  
Ultrastructural Level ◽  
Mitochondrial Membranes ◽  
Hyphal Cell ◽  
Dense Deposits

The enzyme succinate dehydrogenase (SDH, succinate: (acceptor) oxidoreductase, EC 1.3.99.1) was localized by the combined techniques of cytochemistry and electron microscopy in the hyphae of a self-parasitizing isolate of Saprolegnia megasperma Coker. The enzyme was localized in the mitochondrial membranes; its activity was inhibited by malonate. Electron-dense deposits, whose formation was not prevented by the addition of malonate, appeared outside of the hyphal cell walls. No evidence was found at the ultrastructural level within the vegetative hyphae for any abnormalities which could be linked to the phenomenon of self-parasitism.

scholarly journals Kinetic analysis of the mitochondrial quinol-oxidizing enzymes during development of thermogenesis in Arum maculatum L

1996 ◽  
Vol 317 (1) ◽  
pp. 313-319 ◽  
Author(s):  
Graeme R. LEACH ◽  
Klaas KRAB ◽  
David G. WHITEHOUSE ◽  
Anthony L. MOORE
Keyword(s):  
Respiratory Rate ◽  
Succinate Dehydrogenase ◽  
Oxidase Activity ◽  
Alternative Oxidase ◽  
Alternative Pathway ◽  
Respiratory Control ◽  
Stage Of Development ◽  
Activation Level ◽  
Cytochrome Pathway ◽  
Arum Maculatum

The dependence of the rate of oxygen uptake upon the ubiquinone (Q)-pool reduction level in mitochondria isolated during the development of thermogenesis of Arum maculatum spadices has been investigated. At the α-stage of development, the respiratory rate was linearly dependent upon the reduction level of the Q-pool (Qr) both under state-3 and -4 conditions. Progression through the β/γ to the Δ-stage resulted in a non-linear dependence of the state-4 rate on Qr. In the Δ-stage of development, both state-3 and -4 respiratory rates were linearly dependent upon Qr due to a shift in the engagement of the alternative oxidase to lower levels of Qr. Western blot analysis revealed that increased alternative oxidase activity could be correlated with expression of a 35 kDa protein. Respiratory control was only observed with mitochondria in the α-stage of development. At the β/γ-stage of development, the addition of ADP resulted in a significant oxidation of the Q-pool which was accompanied by a decrease in the respiratory rate. This was due either to decreased contribution of the alternative pathway to the overall respiratory rate under state 3 or by deactivation of succinate dehydrogenase activity by ADP. Cold-storage of the spadices at the β-stage of development led to increased activity of both the cytochrome pathway and succinate dehydrogenase, without any change in alternative oxidase activity. Results are discussed in terms of how changes in the activation level of the alternative oxidase and succinate dehydrogenase influence the activity and engagement of the quinol-oxidizing pathways during the development of thermogenesis in A. maculatum.

scholarly journals Iron-sulphur centres in mitochondria from Arum maculatum spadix with very high rates of cyanide-resistant respiration

1977 ◽  
Vol 166 (3) ◽  
pp. 347-355 ◽  
Author(s):  
R Cammack ◽  
J M Palmer
Keyword(s):  
Succinate Dehydrogenase ◽  
Nadh Dehydrogenase ◽  
Electron Paramagnetic Resonance Spectroscopy ◽  
High Rate ◽  
Spin Interaction ◽  
Resonance Spectroscopy ◽  
Paramagnetic Resonance ◽  
Oxidation Reduction ◽  
Fourth Component ◽  
Arum Maculatum

X-band electron-paramagnetic-resonance spectroscopy at 4.2–77K combined with measurements of oxidation-reduction potential was used to identify iron–sulphur centres in Arum maculatum (cuckoo-pint) mitochondria. In the oxidized state a signal with a derivative maximum at g = 2.02 was assigned to succinate dehydrogenase centre S-3. Unreduced particles showed additional signals at g = 2.04 and 1.98 (at 9.2 GHz), which may be due to a spin-spin interaction. In the reduced state a prominent signal at g = 1.93 and 2.02 was resolved into at least three components that could be assigned to centres S-1 and S-2 of succinate dehydrogenase (midpoint potentials −7 and −240 mV respectively at pH 7.2) and a small amount of centre N-1b (e'o= −240 mV) of NADH-ubiquinone reductase. In addition, changes in line shape around −10 mV indicated the presence of a fourth component in this signal. The latter was more readily reduced by NADH than by succinate, suggesting that it might be associated with the external NADH dehydrogenase. The iron-sulphur centres of NADH-ubiquinone reductase were present in an unusually low concentration, indicating that the alternative, non-phosphorylating, NADH dehydrogenase containing a low number of iron-sulphur centres may be responsible for most of the high rate of oxidation of NADH.

Some Observations on Intra-Mitochondrial Crystals

1977 ◽  
Vol 35 ◽  
pp. 406-407
Author(s):  
J. A. Clarke ◽  
D. N. Landon ◽  
P. R. Ward
Keyword(s):  
Cytochrome B ◽  
Mitochondrial Myopathy ◽  
Crystallographic Analysis ◽  
Mitochondrial Membranes ◽  
Electron Microscopes ◽  
Muscle Biopsies

Intra-mitochondrial crystals have been noted in muscle biopsies from patients in a wide variety of diseased states. As far as we are aware, none of these crystals have been subjected to detailed crystallographic analysis. Recently, similar crystals were observed in a biopsy from a patient with a mitochondrial myopathy, characterised by a deficiency in reducible cytochrome b (Morgan-Hughes, J. A., Darveniza, P., Kahn, S. N., Landon, D. N., Sherratt, R. M., Land, J. M. and Clark, J. B., 1977, Brain, In Press). Aldehyde-fixed, osmicated resin imbedded material was examined using Siemens, JEOL and Phillips electron microscopes with goniometer specimen stages. The crystals generally lay between the outer and inner mitochondrial membranes and measured 1 - 3 μm in length and 0.1 - 0.3 μm in width. Characteristically, these crystals revealed specific periodicities.

Intramitochondrial Viruses of Reptilian Cell Origin

1972 ◽  
Vol 30 ◽  
pp. 318-319
Author(s):  
Philip D. Lunger ◽  
H. Fred Clark
Keyword(s):  
Particle Production ◽  
Outer Zone ◽  
Density Variation ◽  
Core Region ◽  
Mitochondrial Membranes ◽  
Virus Particles ◽  
The Core ◽  
Vipera Russelli ◽  
Maturation Stages ◽  
Type Particle

In the course of fine structure studies of spontaneous “C-type” particle production in a viper (Vipera russelli) spleen cell line, designated VSW, virus particles were frequently observed within mitochondria. The latter were usually enlarged or swollen, compared to virus-free mitochondria, and displayed a considerable degree of cristae disorganization.Intramitochondrial viruses measure 90 to 100 mμ in diameter, and consist of a nucleoid or core region of varying density and measuring approximately 45 mμ in diameter. Nucleoid density variation is presumed to reflect varying degrees of condensation, and hence maturation stages. The core region is surrounded by a less-dense outer zone presumably representing viral capsid.Particles are usually situated in peripheral regions of the mitochondrion. In most instances they appear to be lodged between loosely apposed inner and outer mitochondrial membranes.

Structure of contact sites between the outer and inner mitochondrial membranes investigated by HVEM tomography

1996 ◽  
Vol 54 ◽  
pp. 966-967
Author(s):  
C.A. Mannella ◽  
K.F. Buttle ◽  
K.A. O‘Farrell ◽  
A. Leith ◽  
M. Marko
Keyword(s):  
Liver Mitochondrion ◽  
Adenine Nucleotide ◽  
Protein Complexes ◽  
Mitochondrial Membranes ◽  
Electron Microscopic ◽  
Contact Sites ◽  
Transmission Electron ◽  
Precursor Proteins ◽  
Membrane Contacts ◽  
And Function

Early transmission electron microscopy of plastic-embedded, thin-sectioned mitochondria indicated that there are numerous junctions between the outer and inner membranes of this organelle. More recent studies have suggested that the mitochondrial membrane contacts may be the site of protein complexes engaged in specialized functions, e.g., import of mitochondrial precursor proteins, adenine nucleotide channeling, and even intermembrane signalling. It has been suggested that the intermembrane contacts may be sites of membrane fusion involving non-bilayer lipid domains in the two membranes. However, despite growing interest in the nature and function of intramitochondrial contact sites, little is known about their structure.We are using electron microscopic tomography with the Albany HVEM to determine the internal organization of mitochondria. We have reconstructed a 0.6-μm section through an isolated, plasticembedded rat-liver mitochondrion by combining 123 projections collected by tilting (+/- 70°) around two perpendicular tilt axes. The resulting 3-D image has confirmed the basic inner-membrane organization inferred from lower-resolution reconstructions obtained from single-axis tomography.

ACUTE ENZYME HISTOCHEMICAL CHANGES IN THE ZONA GLOMERULOSA OF THE RAT ADRENAL CORTEX

1968 ◽  
Vol 59 (3) ◽  
pp. 508-518
Author(s):  
J. D. Elema ◽  
M. J. Hardonk ◽  
Joh, Koudstaal ◽  
A. Arends
Keyword(s):  
Peritoneal Dialysis ◽  
Succinate Dehydrogenase ◽  
Dehydrogenase Activity ◽  
Adrenal Cortex ◽  
Isocitrate Dehydrogenase ◽  
Hydroxysteroid Dehydrogenase ◽  
Zona Glomerulosa ◽  
Acute Changes ◽  
Glucose 6 Phosphate Dehydrogenase ◽  
Histochemical Changes

ABSTRACT Acute changes in glucose-6-phosphate dehydrogenase and isocitrate dehydrogenase activity in the zona glomerulosa of the rat adrenal cortex were induced by peritoneal dialysis with 5 % glucose. Although less clear, the activity of 3β-ol-hydroxysteroid dehydrogenase also seemed to increase as well. No changes were seen in the activity of succinate dehydrogenase. Dialysis with 0.9 % NaCl had no effect on any of the enzymes investigated. The possible significance of these observations is discussed.

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