Interaction between cytochrome c and cytochrome b5

Stonehuerner, Jacqueline; Williams, J; Millett, Francis

doi:10.1021/bi00591a026

Cited by 101 publications

(47 citation statements)

References 26 publications

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“…Our random-collision model for electron transport (2), presented here in detail (Fig. 4), explains the ionic strength dependency of the functional interaction of cytochrome c with complexes III and IV on the inner membrane and cytochrome b5 on the outer membrane (28) of the intact mitochondrion and fits the data that suggest that cytochrome c has a common binding domain for its interaction with complexes III and IV (29) and cytochrome b5 (30).…”

Section: Discussionsupporting

confidence: 67%

Relationship between lateral diffusion, collision frequency, and electron transfer of mitochondrial inner membrane oxidation-reduction components.

Gupte¹,

Wu²,

Hoechli³

et al. 1984

Proc. Natl. Acad. Sci. U.S.A.

179

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Fluorescence recovery after photobleaching was used to determine the diffusion coefficients of the oxidation-reduction (redox) components ubiquinone, complex III (cytochromes b-cl), cytochrome c, and complex IV (cytochrome oxidase) of the mitochondrial inner membrane. All redox components diffuse in two dimensions as common-pool electron carriers. Cytochrome c diffuses in two and three dimensions concomitantly, and its diffusion rate, unlike that of all other redox components, is modulated along with its activity by ionic strength. The diffusion coefficients established in this study reveal that the theoretical diffusion-controlled collision frequencies of all redox components are greater than their experimental maximum (uncoupled) turnover numbers. Since electron transport is slower than the theoretical limit set by the lateral diffusion of the redox components, ordered chains, assemblies, or aggregates of redox components are not necessary to account for electron transport. Rather, mitochondrial electron transport is diffusion coupled, consistent with a "random-collision model" for electron transport.A number of recent studies suggest that the oxidation-reduction (redox) components of the mitochondrial inner membrane are not arranged as an ordered macromolecular assembly or chain but are free to diffuse laterally and independently of one another in the membrane plane (1-5). These components include the dehydrogenase-containing complexes I and II, cytochrome b-cl complex III, cytochrome oxidase complex IV, cytochrome c, and ubiquinone. Implicit in these studies, and consistent with a "random-collision model," the rate of electron transfer between the membrane redox components may be diffusion coupled and, indeed, diffusion controlled (2).It is the purpose of this paper to report the rates of lateral diffusion for the inner membrane redox components as de-termined by fluorescence recovery after photobleaching and to evaluate such diffusion with respect to electron transport.Based on the diffusion coefficients established experimentally by our study, the calculated diffusion-controlled collision frequencies of all redox components are greater than their experimental maximum turnover numbers. Thus electron transfer between all redox components is diffusion coupled in the mitochondrial inner membrane, consistent with a random-collision model (2) (7), and purified mitoplasts (7) were washed in isolation medium diluted 1:7.5 (40 mOsm) to give spherical inner membranes (8), then washed twice with 0.15 M KCI/1 mM Hepes, pH 7.4, to remove native cytochrome c. Calcium-induced fusion of these inner membranes was carried out in a chamber x100 1Lm high formed between a glass coverslip and slide with Scotch double-stick tape shims. Twenty microliters of the spherical membranes (5 mg/ml) was added to the chamber from one side, and 20 ,ul of 10 mM CaC12/5 mM Hepes, pH 6.4, was added from the other side and then incubated at 35C for 7 min. Fusion was stopped by washing the chamber with 0.05 ml of 10 mM potassium phospha...

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Section: Discussionsupporting

confidence: 67%

Relationship between lateral diffusion, collision frequency, and electron transfer of mitochondrial inner membrane oxidation-reduction components.

Gupte¹,

Wu²,

Hoechli³

et al. 1984

Proc. Natl. Acad. Sci. U.S.A.

179

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“…weak complexes with other electron-transfer proteins including cytochrome c (Stonehuerner, Williams & Millett, 1979;Hartshorn, Mauk, Mauk & Moore, 1987), cytochrome P450 (Tamburini, White & Schenkman, 1985), myoglobin (Livingston, McLachlan, La Mar & Brown, 1985) and methemoglobin. These data suggest that electrostatic forces are involved in complex formation and that as solvent is excluded from the protein-protein interface hydration forces are replaced by salt linkages (Rogers, Pochapsky & Sligar, 1988;Mauk, Barker & Mauk, 1991;Kornblatt, Kornblatt, Hoa & Mauk, 1993).…”

Section: Discussionmentioning

confidence: 99%

Refinement and structural analysis of bovine cytochrome b5 at 1.5 Å Resolution

Durley¹,

Mathews²

1996

Acta Cryst D

146

198

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The structure of bovine liver cytochrome bs, a soluble 93-residue proteolytic fragment of a 16 kDa. membranebound hemoprotein, initially solved at 2.0A resolution, has been refined at 1.5/~ using data collected on a diffractometer. Refinement to 2.0/~ resolution used the Hendrickson-Konnert procedure PROLSQ and was then extended to 1.5 ~ resolution using the program PROFFT. Only residues 3-87 could be identified in the model and these residues together with 93 water molecules gave an agreement factor of R = 0.161 for data in the resolution range 1.5-5/~,. The structure was finally refined using the program X-PLOR, which enabled alternate conformers to be modelled for several surface side chains. Residues 1 and 2 at the amino terminus of the protein and residue 88 near the carboxyl terminus could be identified from these electron-density maps. However the remaining disordered carboxy-terminal residues could not successfully be included in the model. A total of 117 solvent molecules were included in the final refinement to give R =0.164 for the data between 1.5 and 10/~.

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“…These (iii) Cytochrome c and [Cr(en)313' may bind to different regions of the cytochrome bs surface. Cytochrome b5 is a highly anionic protein (net charge -9 at pH 7), and its cation-binding surface is large enough [9] to bind both cytochrome c and [Cr(en)313+ simultaneously.…”

Section: Competition Between Ferricytochrome C Andmentioning

confidence: 99%

“…Characterisation of the structural features of these two complexes in solution provides a useful means of assessing the validity of computer modelling of such complexes. Various lines of experimental work have established that cytochrome bs and c do form a stable bimolecular complex in solution 151, and chemical modification [6,7] and NMR [S] studies of cytochrome c indicate that the Salemme model is approximately correct in identifying the region of cytochrome c that forms the cytochrome 65 interaction domain even though the specific roles of particular residues have not been fully defined.…”

mentioning

confidence: 99%

NMR study of the interaction between cytochrome b₅ and cytochrome c

Hartshorn¹,

Mauk²,

Mauk³

et al. 1987

FEBS Letters

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The interaction between horse cytochrome c and the tryptic fragment of bovine liver microsomal cytochrome b 5 in the absence and presence of [Cr(ethylenediamine)3]Cl3 was studied by 1H NMR spectroscopy. The protein‐protein interaction region on cytochrome b 5 was found to be different from the [Cr(en)3]3+ binding region. The solvent‐exposed propionate‐bearing edge of the haem of cytochrome b 5 is accessible to [Cr(en)3]3+ in the interprotein complex.

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Interaction between cytochrome c and cytochrome b5

Cited by 101 publications

References 26 publications

Relationship between lateral diffusion, collision frequency, and electron transfer of mitochondrial inner membrane oxidation-reduction components.

Relationship between lateral diffusion, collision frequency, and electron transfer of mitochondrial inner membrane oxidation-reduction components.

Refinement and structural analysis of bovine cytochrome b5 at 1.5 Å Resolution

NMR study of the interaction between cytochrome b₅ and cytochrome c

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Interaction between cytochrome c and cytochrome b5

Cited by 101 publications

References 26 publications

Relationship between lateral diffusion, collision frequency, and electron transfer of mitochondrial inner membrane oxidation-reduction components.

Relationship between lateral diffusion, collision frequency, and electron transfer of mitochondrial inner membrane oxidation-reduction components.

Refinement and structural analysis of bovine cytochrome b5 at 1.5 Å Resolution

NMR study of the interaction between cytochrome b5 and cytochrome c

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NMR study of the interaction between cytochrome b₅ and cytochrome c