Mapping Activity-Dependent Quasi-stationary States of Mitochondrial Membranes with Graphene-Induced Energy Transfer Imaging

Graphene-induced energy transfer (GIET) was recently introduced for the precise localization of fluorescent molecules along the optical axis of a microscope. GIET is based on near-field energy transfer from an optically excited fluorophore to a single sheet of graphene. As a proof-of-concept, we demonstrated its potential by determining the distance between the two leaflets of supported lipid bilayers (SLBs) with sub-nanometer accuracy. Here, we use GIET imaging for the three dimensional reconstruction of the mitochondrial membrane architecture. We map two quasi-stationary states of the inner and outer mitochondrial membranes before and during adenosine triphosphate (ATP) synthesis. We trigger the ATP synthesis state in vitro by activating mitochondria with precursor molecules. Our results demonstrate that the inner membrane (IM) approaches the outer membrane (OM) while the outer membrane (OM) does not show a measurable change in average axial position upon activation. As a result, the inter-membrane space (IM-OM distance) is reduced by ~2 nm upon activation of the mitochondria. This direct experimental observation of the subtle dynamics of mitochondrial membranes and the change in inter-membrane distance induced by ATP synthesis is relevant for our understanding of the physical functioning of mitochondria.

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Using Förster-Resonance Energy Transfer to Measure Protein Interactions Between Bcl-2 Family Proteins on Mitochondrial Membranes

Methods in Molecular Biology - Programmed Cell Death ◽

10.1007/978-1-4939-3581-9_15 ◽

2016 ◽

pp. 197-212 ◽

Cited By ~ 4

Author(s):

Justin P. Pogmore ◽

James M. Pemberton ◽

Xiaoke Chi ◽

David W. Andrews

Keyword(s):

Energy Transfer ◽

Protein Interactions ◽

Resonance Energy Transfer ◽

Resonance Energy ◽

Forster Resonance Energy Transfer ◽

Förster Resonance Energy Transfer ◽

Mitochondrial Membranes ◽

Förster Resonance

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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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A quantitative approach to inner shell losses

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s042482010010977x ◽

1978 ◽

Vol 36 (1) ◽

pp. 526-527 ◽

Cited By ~ 2

Author(s):

R.D. Leapman ◽

P. Rez ◽

D.F. Mayers

Keyword(s):

Energy Transfer ◽

Cross Section ◽

Cross Sections ◽

Accurate Determination ◽

Background Intensity ◽

Core Excitation ◽

Quantitative Basis ◽

Cross Section Differential ◽

Bound Electrons

Microanalysis by EELS has been developing rapidly and though the general form of the spectrum is now understood there is a need to put the technique on a more quantitative basis (1,2). Certain aspects important for microanalysis include: (i) accurate determination of the partial cross sections, σx(α,ΔE) for core excitation when scattering lies inside collection angle a and energy range ΔE above the edge, (ii) behavior of the background intensity due to excitation of less strongly bound electrons, necessary for extrapolation beneath the signal of interest, (iii) departures from the simple hydrogenic K-edge seen in L and M losses, effecting σx and complicating microanalysis. Such problems might be approached empirically but here we describe how computation can elucidate the spectrum shape.The inelastic cross section differential with respect to energy transfer E and momentum transfer q for electrons of energy E0 and velocity v can be written as

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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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