共查询到20条相似文献,搜索用时 31 毫秒
1.
J C Chien L C Dickinson T L Mason 《Biochemical and biophysical research communications》1975,63(4):853-857
An improved synthesis for cobalt-cytochrome has been developed; its half reduction potential is ?140 ± 20mV. Reduced Cocyt-3 is oxidized by bovine heart cytochrome oxidase at a rate ~45% that of the native cytochrome . It is not reduced by mitochondrial NADH or succinate cytochrome reductase nor by microsomal NADH or NADPH cytochrome reductase. 相似文献
2.
Thermotropic properties of purified cytochrome and cytochrome have been studied by differential scanning calorimetry under various conditions. Both cytochromes exhibit a single endothermodenaturation peak in the differential scanning calorimetric thermogram. Thermodenaturation temperatures are ionic strength, pH, and redox state dependent. The ferrocytochromes are more stable toward thermodenaturation than the ferricytochromes. The enthalpy changes of thermodenaturation of ferro- and ferricytochrome are markedly dependent on the ionic strength of the solution. The effect of the ionic strength of solution on the enthalpy change of thermodenaturation of cytochrome is rather insignificant. The formation of a complex between cytochromes and at lower ionic strength causes a significant destabilization of the former and a slight stabilization of the latter. The destabilization of cytochrome upon mixing with cytochrome was also observed at high ionic strength, under which conditions no stable complex was detected by physical separation. This suggests formation of a transient complex between these two cytochromes. When cytochrome was complexed with phospholipids, no change in the thermodenaturation temperature was observed, but a great increase in the enthalpy change of thermodenaturation resulted. 相似文献
3.
Resonance Raman spectroscopy of cytochrome c oxidase and electron transport particles with excitation near the Soret band 总被引:3,自引:0,他引:3
I Salmeen L Rimai D Gill T Yamamoto G Palmer C R Hartzell H Beinert 《Biochemical and biophysical research communications》1973,52(3):1100-1107
We report the resonance Raman spectra of cytochrome oxidase, both solubilized and in electron transport particles using laser excitation near the Soret band. As in the spectra of other hemoproteins, such as cytochrome , the shape and intensity of a number of bands change when the oxidation state is varied. However, one of the hemes of solubilized cytochrome oxidase shows redox behavior which is anomalous. Spectra of electron transport particles are dominated by cytochrome oxidase. There are, however, definite differences between spectra of solubilized cytochrome oxidase and electron transport particles in the oxidized states. 相似文献
4.
M Erecińska R Oshino D F Wilson 《Biochemical and biophysical research communications》1980,92(3):743-748
[3H]-p-Azidophenacylbromide-(methyl-4-mercaptobutyrimidate)-cytochrome from was prepared and its properties determined. The radioactive photoaffinity-labeled cytochrome was linked by irradiation into a covalent complex with cytochrome oxidase. Analysis of the complex on SDS-polyacrylamide gels showed that cytochrome bound to one of the smaller subunits of cytochrome oxidase with an apparent molecular weight of 15,000. 相似文献
5.
A cytochrome - cytochrome oxidase complex containing 0.8–1.0 moles of cytochrome per mole of cytochrome oxidase (heme a + a3) was isolated as described by Ferguson-Miller, S., Brautigan, D.L., and Margoliash E., J. Biol. Chem. , 1104 (1976). This complex was reacted with dithiobissuccinimidyl propionate, an 11 Å bridging bifunctional reagent, and the cross-linked products obtained were analyzed by two dimensional gel electrophoresis. Cytochrome was cross-linked to subunit II of cytochrome oxidase. Other cross-linked products were formed involving different subunits of cytochrome oxidase. These included I+V, II+V, III+V, V+VII, IV+VI and IV+VII. Experiments are also described using N,N′-bis(3-succinimidyloxycarbonylpropyl) tartarate. The major product formed with this 18 Å bridging bifunctional reagent was a pair containing II+VI. 相似文献
6.
H.R. Bosshard M. Zürrer H. Schägger G. von Jagow 《Biochemical and biophysical research communications》1979,89(1):250-258
Cytochrome 1, the electron donor for cytochrome , is a subunit of the mitochondrial cytochrome 1 complex (complex III, cytochrome reductase). To test if cytochrome 1 is the cytochrome -binding subunit of the 1 complex, binding of cytochrome to the complex and to isolated cytochrome 1 was compared by a gel-filtration method under non-equilibrium conditions (a 1 complex lacking the Rieske ironsulfur protein was used; von Jagow et al. (1977) Biochim. Biophys. Acta , 549–558). The approximate stoichiometries and binding affinities were found to be very similar. Binding of cytochrome to isolated cytochrome which is another subunit of the reductase was not detectable by the gel-filtration method. Further, the same lysine residues of cytochrome were shielded towards chemical acetylation in the complexes 1 and 1. From this we conclude that the same surface area of cytochrome is in direct contact with cytochrome 1 and with cytochrome 1 in the respective complexes and that therefore cytochrome is most probably the structural ligand for cytochrome in mitochondrial cytochrome reductase. 相似文献
7.
Cytochrome c interaction with membranes. Interaction of cytochrome c with isolated membrane fragments and purified enzymes 总被引:1,自引:0,他引:1
The midpoint redox potential of cytochrome c and the electron paramagnetic resonance spectra of nitroxide labeled cytochromes c were measured as a function of binding to purified cytochrome c oxidase, cytochrome c peroxidase, cytochrome b5 and succinate—cytochrome c reductase. The midpoint redox potential of horse heart cytochrome c is lowered in the presence of cytochrome c oxidase and succinate-cytochrome c reductase, but is unchanged in the presence of cytochrome c peroxidase or cytochrome b5. Further evidence of binding is afforded by an increase in correlation time, Tc, of the spin-labeled cytochrome c at methionine 65 upon binding to cytochrome c peroxidase, cytochrome c oxidase and succinate—cytochrome c reductase. The changes in midpoint redox potential and electron paramagnetic resonance spectrum of the spin-labeled derivative upon binding can either be the consequence of specific interaction leading to formation of ES complexes, or it can be due to nonspecific electrostatic interaction between positively charged groups on cytochrome c and negatively charged groups on the isolated cytochrome preparations. 相似文献
8.
M. Erecińska 《Biochemical and biophysical research communications》1977,76(2):495-501
Three lysine residues of horse heart cytochrome were modified by reaction with methyl-4-mercaptobutyrimidate hydrochloride and the free SH group of the latter was covalently linked to p-azidophenacyl bromide yielding a photoaffinity-labeled cytochrome . The photoaffinity-labeled cytochrome was bound by irradiation into a covalent complex with cytochrome oxidase. 相似文献
9.
R A Capaldi R L Bell T Branchek 《Biochemical and biophysical research communications》1977,74(2):425-433
The order of migration of polypeptides in both cytochrome oxidase and ubiquinone cytochrome reductase has been found to differ depending on the gel conditions used. Thus the nomenclatures or numbering systems being used for the subunits of these membrane complexes by workers using Weber-Osborn gels is not the same as that being used in laboratories which use the Swank-Munkres or Fairbanks gel procedure. 相似文献
10.
Y Fujihira T Kuwana C R Hartzell 《Biochemical and biophysical research communications》1974,61(2):538-543
The repetitive, equilibrium redox cycling of cytochrome , cytochrome oxidase, or mixtures thereof has been made possible by the use of the oxidant, ferricinium ion. This ion is electrochemically generated by the use of non-ionic detergent solubilized ferrocene which is apparently incorporated as micelles and readily electron transfers with an electrode. The couple equilibrates rapidly with these heme proteins. Electrochemically generated benzylviologen radical cations are used as the reductant. The EO′ values for cytochrome oxidase at pH 7.0 are 209 ± 15 mv (2e?) and 340 ± 15 mv (2e?). 相似文献
11.
V M Darley-Usmar R A Capaldi M T Wilson 《Biochemical and biophysical research communications》1981,103(4):1223-1230
The cysteine residues in beef cytochrome oxidase (E.C.1.9.3.1) which act as ligands to a redox site have been located in the C-terminal portion of subunit II. 相似文献
12.
C H Seiter R Margalit R A Perreault 《Biochemical and biophysical research communications》1979,86(3):473-477
Cytochrome was chemically coupled to cytochrome oxidase using the reagent 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide (EDC) which couples amine groups to carboxyl residues. The products of this reaction were analyzed on 2.5–27% polyacrylamide gradient gels electrophoretically. Since cytochrome binds to cytochrome oxidase electrostatically in an attraction between certain of its lysine residues and carboxyl residues on the oxidase surface, EDC is an especially appropriate reagent probe for binding-subunit studies. Coupling of polylysine to cytochrome oxidase using EDC was also performed, and the products of this reaction indicate that polylysine, an inhibitor of the cytochrome reaction with oxidase, binds to the same oxidase subunit as does cytochrome , subunit IV in the gel system used. 相似文献
13.
The addition of formate to oxidized cytochrome oxidase (ferrocytochrome : oxygen oxidoreductase, EC 1.9.3.1) causes the appearance of a high spin heme signal at g = 6 and a splitting of g = 3 signal to g = 2.98 and 3.07. When formate-cytochrome oxidase is reduced, the g = 2.98 signal decreases significantly. The spectrophotometric studies showed that formate is a specific ligand to cytochrome 3. Data suggest that binding of formate to oxidized cytochrome oxidase produces a ligand-3 interaction leading to the splitting of g = 3 signal hitherto considered as due to cytochrome . Thus both cytochrome and 3 contribute to the resonance of g = 3 signal of cytochrome oxidase. 相似文献
14.
Charge distribution in electron transport components: cytochrome c and cytochrome c oxidase mixtures
Mixtures of cytochrome oxidase and cytochrome have been titrated by coulometrically generated reductant, methyl viologen radical cation, and physiological oxidant, O2. Charge distribution among the heme components in mixtures of these two redox enzymes has been evaluated by monitoring the absorbance changes at 605 and 550 nm. Differences in the pathway of the electron transfer process during a reduction cycle as compared to an oxidation cycle are indicated by variations found in the absorbance behavior of the heme components during successive reductive and oxidative titrations. It is apparent that the potential of the cytochrome heme is dependent upon whether oxidation or reduction is occurring. 相似文献
15.
A Novel function of cytochrome C (555, Chlorobium thiosulfatophilum) in oxidation of thiosulfate 总被引:2,自引:0,他引:2
Thiosulfate-cytochrome c-551 reductase derived from has been highly purified. The enzyme reduces cytochrome in the presence of thiosulfate while cytochrome -555 of the organism is not reduced by the enzyme. Cytochrome -555 reacts with the enzyme at an appreciable rate only in the presence of cytochrome -551. However, the reduction rate of cytochrome -551 by the enzyme is greatly enhanced on addition of a catalytic amount of cytochrome -555. Therefore, cytochrome -555 seems to function as an effector on thiosulfate-cytochrome -551 reductase as well as it acts as the electron donor to the light-excited chlorobium chlorophylls. 相似文献
16.
W Rouslin 《Biochemical and biophysical research communications》1976,73(2):364-369
When bakers' yeast cells which had been grown anaerobically in galactose were aerated in the presence of 10% glucose, they showed a 40% decrease in [14C]-leucine incorporation into a washed mitochondrial membrane fraction compared with cells which had been aerated in a low glucose medium. The observed catabolite repression of membrane protein synthesis was primarily due to a decrease in cytoplasmic translational activity, but this repression was entirely dependent upon concomitant mitochondrial translation. The inductions of reduced coenzyme Q cytochrome reductase (complex III) and of cytochrome oxidase (complex IV) activities were repressed 30 and 60%, respectively, by aeration of the cells for 8 hours in 10% glucose. The catabolite repression of the formation of these two inner membrane complexes was again shown to be dependent upon concomitant mitochondrial translation. Both the amino acid incorporation and enzyme induction data suggest that catabolite repression of both cytoplasmically and mitochondrially translated mitochondrial membrane proteins is mediated through a mitochondrially translated repressor. 相似文献
17.
Rats fed a copper-deficient diet for eight weeks showed a large decrease in cytochrome oxidase in heart, spleen, liver, lung, and pancreas but no significant change in kidney and brain. Three injections of human or rat ceruloplasmin over a five day period greatly increased cytochrome oxidase activity in spleen, liver, heart and lung. Rats receiving CuCl2, Cu-histidine, and Cu-albumin produced a smaller and slower increase in cytochrome oxidase compared to ceruloplasmin treated animals. In Cu-histidine treated rats, the increase in enzyme activity did not occur until after the plasma ceruloplasmin level reached a maximal value. It is concluded that ceruloplasmin functions as a primary copper transport protein from which copper atoms are transferred to cytochrome oxidase and probably other copper containing proteins. 相似文献
18.
The effect of pretreatment with phenobarbitone, rifampicin, β-naphthoflavone, antipyrine and spironolactone on the irreversible binding of ethynyloestradiol to guinea pig liver microsomes has been examined and the corresponding changes in microsomal P-450 content and cytochrome reductase activity measured. Rifampicin produced the greatest increase (220%) in irreversible binding while phenobarbitone produced the greatest increase in both microsomal P-450 content (172%) and cytochrome reductase activity (210%). There was no correlation of irreversible binding with either microsomal P-450 content or with cytochrome reductase activity. 相似文献
19.
Rat liver microsomal NADH-cytochrome reductase activity is stimulated by 20 μM thyroxine . Thyroxine does not influence microsomal NADH-dichlorophenolindophenol reductase, NADPH-cytochrome reductase, or NADPH-dichlorophenolindophenol reductase activity. Stimulation of NADH-cytochrome reductase activity is not mediated by super-oxide and is likely due to enhanced reduction or oxidation of cytochrome 5. 相似文献
20.
B L Trumpower 《Biochemical and biophysical research communications》1976,70(1):73-80
A protein named oxidation factor can be reversibly removed from succinate-cytochrome reductase complex and shown to be required for electron transfer between succinate and cytochrome . This protein is required for reduction of cytochrome and, in the presence of antimycin, for reduction of both cytochromes and . These results are consistent with a protonmotive Q cycle mechanism in which the oxidation factor catalyzes electron transfer from reduced quinone to cytochrome and thus liberates from reduced quinone one of two protons required for energy conservation during electron transfer through the cytochrome complex. 相似文献