Biogenesis of Lipids and Proteins within Mitochondrial Membranes

Some Observations on Intra-Mitochondrial Crystals

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100079486 ◽

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.

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Intramitochondrial Viruses of Reptilian Cell Origin

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100094851 ◽

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.

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

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100167299 ◽

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.

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Faculty Opinions recommendation of Tim50 is a subunit of the TIM23 complex that links protein translocation across the outer and inner mitochondrial membranes.

Faculty Opinions – Post-Publication Peer Review of the Biomedical Literature ◽

10.3410/f.1008589.177333 ◽

2002 ◽

Author(s):

David Andrews

Keyword(s):

Protein Translocation ◽

Mitochondrial Membranes ◽

A Subunit

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The Influence of Ultra-Low Concentrations of Potassium Anphen on the Bioenergetic Characteristics of Mitochondria

Current Bioactive Compounds ◽

10.2174/1573407214666181116093909 ◽

2020 ◽

Vol 16 (4) ◽

pp. 537-542

Author(s):

Zhigacheva Irina ◽

Volodkin Aleksandr ◽

Rasulov Maksud

Keyword(s):

Functional State ◽

Membrane Lipids ◽

Biological Effects ◽

Dose Dependence ◽

Stress Factors ◽

Mitochondrial Membranes ◽

Oxidation Rates ◽

Pea Seedlings ◽

Low Concentrations ◽

Wide Range

Background: One of the main sources of ROS in stress conditions is the mitochondria. Excessive generation of ROS leads to oxidation of thiol groups of proteins, peroxidation of membrane lipids and swelling of the mitochondria. In this regard, there is a need to search for preparationsadaptogens that increase the body's resistance to stress factors. Perhaps, antioxidants can serve as such adaptogens. This work aims at studying the effect of antioxidant; the potassium anphen in a wide range of concentrations on the functional state of 6 day etiolated pea seedlings mitochondria (Pisum sativum L). Methods: The functional state of mitochondria was studied per rates of mitochondria respiration, by the level of lipid peroxidation and study of fatty acid composition of mitochondrial membranes by chromatography technique. Results: Potassium anphen in concentrations of 10-5 - 10-8 M and 10-13-10-16 prevented the activation of LPO in the mitochondrial membranes of pea seedlings, increased the oxidation rates of NAD-dependent substrates and succinate in the respiratory chain of mitochondria that probably pointed to the anti-stress properties of the drug. Indeed, the treatment of pea seeds with the preparation in concentrations of 10-13 M prevented the inhibition of growth of seedlings in conditions of water deficiency. Conclusion: It is assumed that the dose dependence of the biological effects of potassium anphen and the manifestation of these effects in ultra-low concentrations are due to its ability in water solutions to form a hydrate containing molecular ensembles (structures).

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