Cytochrome c‐cytochrome aa3 complex formation at low ionic strength studied by aqueous two‐phase partition

Petersen, Lars Chr.

doi:10.1016/0014-5793(78)80916-8

Cited by 32 publications

(10 citation statements)

References 21 publications

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“…This specificity of association, the proximity of the binding site to the active site of cytochrome c, the absolute conservation ofArg-91 and the known influence on electron-transfer rates o}f the presence of some of.the anions we have examined (Ferguson-Miller et al, 1976, 1978 have led us to propose that such binding might play a regulatory role in the interaction of cytochrome c with other components of mitochondrial redox enzyme systems. We have therefore looked at one of the ways in which such a system could act, through a direct effect on the redox potential of the protein.…”

Section: Dhch-arginine Residue(s)mentioning

confidence: 93%

“…These observations could account for the differences in affinity between oxidation states for cytochrome c oxidase (Petersen, 1978;Bill & Azzi, 1984).…”

Section: Introductionmentioning

confidence: 93%

“…We thus propose that there exists on the surface of ferricytochrome c a highly structured binding site with a strong affinity for ATP, but which can also bind its components, ADP and Pi. In ferrocytochrome c this site is lost, presumably as a result of the small conformation differences that exist between the two oxidation states (Petersen, 1978;Takano & Dickerson, 1981a,b). A very precise association between ATP and the site is also implied by the insensitivity of ADP and Pi binding to a change in oxidation state .…”

Section: Dhch-arginine Residue(s)mentioning

confidence: 99%

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The oxidation-state-dependent ATP-binding site of cytochrome c. Implication of an essential arginine residue and the effect of occupancy on the oxidation-reduction potential

Corthésy¹,

Wallace²

1988

Biochemical Journal

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Arg-91 is not part of the active site of cytochrome c that mediates binding and electron transfer, yet it is absolutely conserved in eukaryotic cytochromes c, indicating a special function. The physicochemical properties of analogues are unaffected by the modification of this residue, so they can be used with confidence to study the role of Arg-91. We have established limiting conditions under which this residue alone is specifically modified by cyclohexane-1,2-dione, and have subsequently shown that ATP, and to a lesser extent ADP or P1, protects it from the action of the reagent in an oxidation-state-dependent manner. These observations strongly support the idea that this site exerts a controlling influence on cytochrome c activity in the electron transport or other cellular redox systems, and we have commenced a study of how that influence might operate. We find that the redox potentials of both cytochrome c and analogue are little affected by changing ATP or Pi concentrations.

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Section: Dhch-arginine Residue(s)mentioning

confidence: 93%

“…These observations could account for the differences in affinity between oxidation states for cytochrome c oxidase (Petersen, 1978;Bill & Azzi, 1984).…”

Section: Introductionmentioning

confidence: 93%

Section: Dhch-arginine Residue(s)mentioning

confidence: 99%

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The oxidation-state-dependent ATP-binding site of cytochrome c. Implication of an essential arginine residue and the effect of occupancy on the oxidation-reduction potential

Corthésy¹,

Wallace²

1988

Biochemical Journal

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“…Reconstituted complexes, consisting of F-actin and tropomyosin [ 1 13 or F-actin, tropomyosin and troponin [6,111, are able to bind greater amounts of enzymes than F-actin alone, though with slightly less strength. It was recently shown that if a muscle homogenate was applied to a column of Sepharose 4B with a covalently bound F-actin-tropomyosin complex varying amounts of all glycolytic enzymes, with the exception of enolase, were retained by the column at high ionic strength (150 mM KCI) [7].…”

mentioning

confidence: 99%

Association of rabbit muscle glycolytic enzymes with filamentous actin

Westrin

Backman

1983

European Journal of Biochemistry

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The association between purified glycolytic enzymes and filamentous actin from rabbit muscle has been studied by counter-current distribution. The co-distribution of a glycolytic enzyme and filamentous actin leads to a significant change in the counter-current distribution profile of the enzyme whereas that of actin is unaffected. The changes in the distribution profiles clearly demonstrated that all glycolytic enzymes studied, though to different extents, bind to filamentous actin.The aqueous two-phase system used for the studies contained dextran, poly(ethyleneglyco1) and 150 millimolal potassium phosphate buffer, pH 7.0. Since the ionic strength of the two-phase system is determined mainly by the buffer, the glycolytic enzymes are evidently able to associate with filamentous actin, at least in the presence of neutral polymers, at ionic strengths comparable to or higher than those assumed to prevail in vivo.

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“…Since the ionic strength of the medium is known to affect complex formation [4,5,7,8,11,16] the reactions were studied both at low and high concentrations of the phosphate buffer used.…”

mentioning

confidence: 99%

On the Mechanism of the Cytochrome c Oxidase Reaction. Bound Fe(III) Cytochrome c as an Intermediate in the Reductive Half Reaction

Petersen¹,

Cox²

1980

European Journal of Biochemistry

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The reaction between cytochrome c and Cytochrome aa3 in the presence of reductant was studied using transient and steady‐state kinetic methods. To investigate the effect of complex formation the reaction was studied at both high and low ionic strength in potassium phosphate buffer (pH 7.4). Steady‐state kinetic experiments were performed in which the oxidation level of cytochrome c was measured during the anaerobic‐aerobic transition of a system containing cytochrome aa3, cytochrome c and ascorbate. Such measurements confirm previous suggestions [Mochan and Nicholls (1972) Biochim, Biophys. Acta. 172, 37–51] that cytochrome c forms a complex with cytochrome oxidase which is not easily accessible to ascorbate reduction. The results suggest that one oxidised cytochrome c per oxidase is bound at low ionic strength. The reduction of ‘oxygen‐pulsed’ oxidase in the presence of dithionite and various concentrations of cytochrome c was investigated by stopped flow spectrophotometry. Exposure of buffer containing cytochrome aa3, cytochrome c and dithionite to a brief pulse of oxygen caused an immediate oxidation of the oxidase and of up to one equivalent of cytochrome c per oxidase. Under conditions where complex formation is favoured the subsequent reduction of cytochrome c is many times slower than can be accounted for by the reaction between dithionite and free cytochrome c. This suggests that the bound oxidised cytochrome c is not readily accessible to dithionite reduction. It is proposed that the complex between oxidised cytochrome c and the oxidase is an intermediate of the reductive half‐reaction and it is shown that the kinetic responses of the complex are rapid enough to be in agreement with this suggestion.

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Cytochrome c‐cytochrome aa₃ complex formation at low ionic strength studied by aqueous two‐phase partition

Cited by 32 publications

References 21 publications

The oxidation-state-dependent ATP-binding site of cytochrome c. Implication of an essential arginine residue and the effect of occupancy on the oxidation-reduction potential

The oxidation-state-dependent ATP-binding site of cytochrome c. Implication of an essential arginine residue and the effect of occupancy on the oxidation-reduction potential

Association of rabbit muscle glycolytic enzymes with filamentous actin

On the Mechanism of the Cytochrome c Oxidase Reaction. Bound Fe(III) Cytochrome c as an Intermediate in the Reductive Half Reaction

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