Hydrodynamic properties of porin isolated from outer membranes of rat liver mitochondria

Lindén, Monica; Gellerfors, Pär

doi:10.1016/0005-2736(83)90177-3

Cited by 60 publications

(20 citation statements)

References 21 publications

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“…This hypothetical 'monomer' barrel would have a carbon-backbone diameter of 3.8 nm if the ~-chains were tilted 38 ° relative to the long axis of the barrel, very close to the energetically optimal tilt angle of 36 ° (Guy, H.R., personal communication). Thus, although there is biochemical and functional evidence that favors a 'dimer' VDAC channel [1,16], a monomer channel cannot presently be eliminated on the basis of existing structural data.…”

Section: Resultsmentioning

confidence: 99%

Diameter of the mitochondrial outer membrane channel: Evidence from electron microscopy of frozen‐hydrated membrane crystals

Mannella¹,

Guo²,

Cognon³

1989

FEBS Letters

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The average projected density of mitochondrial outer membrane channels has been obtained from electron microscopic images of unstained, frozen-hydrated two-dimensional crystals. The density map is consistent with the projection of hollow, thin-walled cylinders aligned normal to the membrane plane with a diameter of 3.8 + 0.1 nm. This diameter closely matches that of the largest/~-barrel that can be formed from one copy of the 30-kDa mitochondrial outer membrane channel protein.

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Section: Resultsmentioning

confidence: 99%

Diameter of the mitochondrial outer membrane channel: Evidence from electron microscopy of frozen‐hydrated membrane crystals

Mannella¹,

Guo²,

Cognon³

1989

FEBS Letters

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“…Thus, even if the channel is formed by two porin molecules, as sedimentation experiments suggest [10], as many as one third of the positively charged groups (22 of 68) should move through half of the externally applied voltage (or a greater part of the charges move through a smaller fraction of the field). This apparently means that no localized voltage sensor exists in the porin channel structure.…”

Section: Discussionmentioning

confidence: 99%

The gate of mitochondrial porin channel is controlled by a number of negative and positive charges

Mirzabekov¹,

Ermishkin²

1989

FEBS Letters

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Negatively charged carboxyl groups of mitochondrial porin have been converted into positively charged ones by means of reaction with water-soluble carbodiimide in the presence of ethylenediamine. Properties of channels formed in a planar lipid bilayer by native and modified porins are compared. Amidation has only little influence on the porin channel-forming activity as well as on the open-state conductance of the channel. However, the modification results in a significant enhancement of the voltage dependence of the channel gating and in an increase of the anionic selectivity. It is suggested that the voltage sensor of the porin channel gate is composed of a number of negative ( > 14) and positive (> 22) charges.

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“…The results indicate that both soluble purified VDAC and membrane-embedded VDAC can assemble into tetramers and suggest that a dynamic equilibrium between the monomeric and tetrameric states of VDAC exists. Indeed, in other studies using purified rat liver or Neurospora crassa, VDAC was suggested to exist as a dimer, and also may be in a trimeric form [22,23,38]. Using brain mitochondria [39] or recombinant human VDAC [40], the existence of VDAC dimers to tetramers was also reported.…”

Section: Vdac Has a Dynamic Oligomeric Structurementioning

confidence: 92%

“…Indeed, evidence consistent with oligomerization of VDAC has been presented; the hydrodynamic properties of purified rat liver VDAC suggest that isolated VDAC exists as dimers [22] or oligomers [23], whereas cross-linking of yeast OMM revealed the existence/ formation of VDAC dimers, trimers and oligomers [24]. A low-resolution (15 Å; 1 Å = 0.1 nm) surface structure of VDAC, obtained by metal shadowing and cryoelectron microscopy of Abbreviations used: ANT, adenine nucleotide translocator; CM-cellulose, carboxymethylcellulose; DFDNB, 1,5-difluoro-2,4-dinitrobenzene; DMS, dimethyl suberimidate; DSP, dithiobis(succinimidyl propionate); DTT, DL-dithiothreitol; EGS, ethylenglycolbis(succinimidylsuccinate); EITC, eosin 5-isothiocyanate; FRET, fluorescence resonance energy transfer; HK, hexokinase; LDAO, lauryl-(dimethyl)-amineoxide; β-OG, n-octyl-β-D-glucopyranoside; OMM and IMM, outer and inner mitochondrial membranes; PLB, planar lipid bilayer; PTP, permeability transition pore; RuR, Ruthenium Red; VDAC, voltagedependent anion channel.…”

Section: Introductionmentioning

confidence: 99%

Oligomeric states of the voltage-dependent anion channel and cytochrome c release from mitochondria

Zalk

Israelson

Garty

et al. 2005

Biochemical Journal

199

234

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The VDAC (voltage-dependent anion channel) plays a central role in apoptosis, participating in the release of apoptogenic factors including cytochrome c. The mechanisms by which VDAC forms a protein-conducting channel for the passage of cytochrome c are not clear. The present study approaches this problem by addressing the oligomeric status of VDAC and its role in the induction of the permeability transition pore and cytochrome c release. Chemical cross-linking of isolated mitochondria or purified VDAC with five different reagents proved that VDAC exists as dimers, trimers or tetramers. Fluorescence resonance energy transfer between fluorescently labelled VDACs supports the concept of dynamic VDAC oligomerization. Mitochondrial cross-linking prevented both permeability transition pore opening and release of cytochrome c, yet had no effect on electron transport or Ca 2+ uptake. Bilayer-reconstituted purified cross-linked VDAC showed decreased conductance and voltage-independent channel activity. In the dithiobis(succinimidyl propionate)-cross-linked VDAC, these channel properties could be reverted to those of the native VDAC by cleavage of the cross-linking. Cross-linking of VDAC reconstituted into liposomes inhibited the release of the proteoliposome-encapsulated cytochrome c. Moreover, encapsulated, but not soluble cytochrome c induced oligomerization of liposome-reconstituted VDAC. Thus the results indicate that VDAC exists in a dynamic equilibrium between dimers and tetramers and suggest that oligomeric VDAC may be involved in mitochondriamediated apoptosis.

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Hydrodynamic properties of porin isolated from outer membranes of rat liver mitochondria

Cited by 60 publications

References 21 publications

Diameter of the mitochondrial outer membrane channel: Evidence from electron microscopy of frozen‐hydrated membrane crystals

Diameter of the mitochondrial outer membrane channel: Evidence from electron microscopy of frozen‐hydrated membrane crystals

The gate of mitochondrial porin channel is controlled by a number of negative and positive charges

Oligomeric states of the voltage-dependent anion channel and cytochrome c release from mitochondria

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