Studies on Cytochrome c Peroxidase

Yonetani, Takashi; Ray, G. Stewart

doi:10.1016/s0021-9258(18)97090-0

Cited by 257 publications

(39 citation statements)

References 14 publications

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“…A value of LEmM = 60 litre * mmolh * cmwas used for E423-E404, calculated from Yonetani (1965). Yeast cytochrome c peroxidase, prepared by the method of Yonetani & Ray (1965), was kindly supplied by Professor T. Yonetani, Johnson Research Foundation, University ofPennsylvania. Cytochrome b was monitored at E563-E575 (AEmM=22 litre mmolV cm-') in a Johnson Research Foundation double-beam spectrophotometer.…”

Section: Methodsmentioning

confidence: 99%

The mitochondrial generation of hydrogen peroxide. General properties and effect of hyperbaric oxygen

Boveris

Chance

1973

Biochemical Journal

2,360

1,154

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1. Pigeon heart mitochondria produce H(2)O(2) at a maximal rate of about 20nmol/min per mg of protein. 2. Succinate-glutamate and malate-glutamate are substrates which are able to support maximal H(2)O(2) production rates. With malate-glutamate, H(2)O(2) formation is sensitive to rotenone. Endogenous substrate, octanoate, stearoyl-CoA and palmitoyl-carnitine are by far less efficient substrates. 3. Antimycin A exerts a very pronounced effect in enhancing H(2)O(2) production in pigeon heart mitochondria; 0.26nmol of antimycin A/mg of protein and the addition of an uncoupler are required for maximal H(2)O(2) formation. 4. In the presence of endogenous substrate and of antimycin A, ATP decreases and uncoupler restores the rates of H(2)O(2) formation. 5. Reincorporation of ubiquinone-10 and ubiquinone-3 to ubiquinone-depleted pigeon heart mitochondria gives a system in which H(2)O(2) production is linearly related to the incorporated ubiquinone. 6. The generation of H(2)O(2) by pigeon heart mitochondria in the presence of succinate-glutamate and in metabolic state 4 has an optimum pH value of 7.5. In states 1 and 3u, and in the presence of antimycin A and uncoupler, the optimum pH value is shifted towards more alkaline values. 7. With increase of the partial pressure of O(2) to the hyperbaric region the formation of H(2)O(2) is markedly increased in pigeon heart mitochondria and in rat liver mitochondria. With rat liver mitochondria and succinate as substrate in state 4, an increase in the pO(2) up to 1.97MPa (19.5atm) increases H(2)O(2) formation 10-15-fold. Similar pO(2) profiles were observed when rat liver mitochondria were supplemented either with antimycin A or with antimycin A and uncoupler. No saturation of the system with O(2) was observed up to 1.97MPa (19.5atm). By increasing the pO(2) to 1.97MPa (19.5atm), H(2)O(2) formation in pigeon heart mitochondria with succinate as substrate increased fourfold in metabolic state 4, with antimycin A added the increase was threefold and with antimycin A and uncoupler it was 2.5-fold. In the last two saturation of the system with oxygen was observed, with an apparent K(m) of about 71kPa (0.7-0.8atm) and a V(max.) of 12 and 20nmol of H(2)O(2)/min per mg of protein. 8. It is postulated that in addition to the well-known flavin reaction, formation of H(2)O(2) may be due to interaction with an energy-dependent component of the respiratory chain at the cytochrome b level.

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Section: Methodsmentioning

confidence: 99%

The mitochondrial generation of hydrogen peroxide. General properties and effect of hyperbaric oxygen

Boveris

Chance

1973

Biochemical Journal

2,360

1,154

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“…Cytochrome c peroxidase was isolated from commercial bakers' yeast according to the procedure of Yonetani and co-workers (Yonetani & Ray, 1965;Yonetani et al, 1966). The purity index (ratio of absorbance at 408 to 282 nm) of all preparations used was 1.18 or greater.…”

Section: Methodsmentioning

confidence: 99%

Calorimetric studies of the thermal denaturation of cytochrome c peroxidase

Kresheck¹,

Erman²

1988

Biochemistry

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Two endotherms are observed by differential scanning calorimetry during the thermal denaturation of cytochrome c peroxidase at pH 7.0. The transition midpoint temperatures (tm) were 43.9 +/- 1.4 and 63.3 +/- 1.6 degrees C, independent of concentration. The two endotherms were observed at all pH values between 4 and 8, with the transition temperatures varying with pH. Precipitation was observed between pH 4 and 6, and only qualitative data are presented for this region. The thermal unfolding of cytochrome c peroxidase was sensitive to the presence and ligation state of the heme. Only a single endotherm was observed for the unfolding of the apoprotein, and this transition was similar to the high-temperature transition in the holoenzyme. Addition of KCN to the holoenzyme increases the midpoint of the high-temperature transition whereas the low-temperature transition was increased upon addition of KF. Binding of the natural substrate ferricytochrome c to the enzyme increases the low-temperature transition by 4.8 +/- 1.3 degrees C but has no effect on the high-temperature transition at pH 7. The presence of cytochrome c peroxidase decreases the stability of cytochrome c, and both proteins appear to unfold simultaneously. The results are discussed in terms of the two domains evident in the X-ray crystallographic structure of cytochrome c peroxidase.

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“…It is clear, then, that the structural architecture of the APX and CcP enzymes is subtly different: the structural features required for substrate binding in APX are not present in CcP, and vice versa. These differences satisfactorily account for the low activity of CcP towards ascorbate 173 and of APX towards cytochrome c. 24…”

Section: Substrate Specificitymentioning

confidence: 83%

Understanding functional diversity and substrate specificity in haem peroxidases: what can we learn from ascorbate peroxidase?

Raven

2003

Nat. Prod. Rep.

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This review summarizes the most recent advances in our understanding of the haem enzyme ascorbate peroxidase. The aim is to show how the combined applications of protein engineering, mechanistic and structural studies can be used to provide an overall picture of enzyme catalysis, and how this information can be used to provide new insight into other, more well-characterized peroxidases (in particular cytochrome c peroxidase). It contains 212 references and covers literature up to March 2003.

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Studies on Cytochrome c Peroxidase

Cited by 257 publications

References 14 publications

The mitochondrial generation of hydrogen peroxide. General properties and effect of hyperbaric oxygen

The mitochondrial generation of hydrogen peroxide. General properties and effect of hyperbaric oxygen

Calorimetric studies of the thermal denaturation of cytochrome c peroxidase

Understanding functional diversity and substrate specificity in haem peroxidases: what can we learn from ascorbate peroxidase?

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