The extinction coefficient of cytochrome c

Gelder, B.F. Van; Slater, E.C.

doi:10.1016/0006-3002(62)90073-2

Cited by 673 publications

(208 citation statements)

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“…Iron free (porphyrin) cytochrome c was obtained as reported by De Kok et al [12]. Absorbance coefficients used for cytochrome aa3 (reduced minus oxidized) were 24.0 mM -I • cm -I at 605 nm [13], for cytochrome c (reduced minus oxidized) 21.1 mM -I" cm -I at 550 nm [14], and for porphyrin cytochrome c 13.0 mM -~ • cm -~ at 504 nm [12].…”

Section: Methodsmentioning

confidence: 99%

The pre-steady state reaction of ferrocytochrome c with the cytochrome c-cytochrome aa3 complex

Veerman

Wilms

Casteleijn

et al. 1980

Biochimica et Biophysica Acta (BBA) - Bioenergetics

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Section: Methodsmentioning

confidence: 99%

The pre-steady state reaction of ferrocytochrome c with the cytochrome c-cytochrome aa3 complex

Veerman

Wilms

Casteleijn

et al. 1980

Biochimica et Biophysica Acta (BBA) - Bioenergetics

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“…Concentrations were determined by electronic absorbance spectroscopy using e 410 = 106,100 M À1 cm À1 for the Fe(III) state [30]. MCD-monitored potentiometric titrations were performed on cytochrome c samples of 6 lM concentration in 20 mM Hepes and 50 mM KCl (pH 7.4) containing the following mediators (each at 4 lM concentration): potassium ferricyanide, phenazine methosulfate, tetramethyl-p-phenylene diamine, anthraquinone-2,6-disulfonic acid, 2-anthraquinone sulfonic acid, 2-methyl-1,4-naphthoquinone, and tetramethyl-p-benzoquinone.…”

Section: Potentiometry Of P Pantotrophus Pseudoazurin and Horse Hearmentioning

confidence: 99%

Probing a Complex of Cytochromecand Cardiolipin by Magnetic Circular Dichroism Spectroscopy: Implications for the Initial Events in Apoptosis

et al. 2011

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a b s t r a c tMagnetic circular dichroism (MCD) spectra, at ultraviolet-visible or near-infrared wavelengths (185-2000 nm), contain the same transitions observed in conventional absorbance spectroscopy, but their bisignate nature and more stringent selection rules provide greatly enhanced resolution. Thus, they have proved to be invaluable in the study of many transition metal-containing proteins. For mainly technical reasons, MCD has been limited almost exclusively to the measurement of static samples. But the ability to employ the resolving power of MCD to follow changes at transition metal sites would be a potentially significant advance. We describe here the development of a cuvette holder that allows reagent injection and sample mixing within the 50-mm-diameter ambient temperature bore of an energized superconducting solenoid. This has allowed us, for the first time, to monitor time-resolved MCD resulting from in situ chemical manipulation of a metalloprotein sample. Furthermore, we report the parallel development of an electrochemical cell using a three-electrode configuration with physically separated working and counter electrodes, allowing true potentiometric titration to be performed within the bore of the MCD solenoid.Ó 2011 Elsevier Inc. All rights reserved.Magnetic circular dichroism (MCD) 1 spectroscopy, at ultraviolet-visible and near-infrared wavelengths (185-2000 nm), has proved to be invaluable in the study of metalloproteins containing cofactors such as heme [1][2][3], non-heme iron [4], iron-sulfur clusters [5][6][7][8], cobalt [9,10], nickel [11][12][13], and copper [14,15]. The technique measures the apparent circular dichroism (CD) induced by a magnetic field [16]. Despite similarities in the instrumentation used, the observation of MCD is not dependent on the chirality of the protein; the method is equally applicable to racemic model complexes [17]. The magnetic field will always induce signals across wavelengths at which the substance absorbs. Thus, MCD spectra contain the same electronic transitions observed in conventional absorbance spectroscopy, but the bisignate nature of the spectrum provides enhanced resolution and greater detail. This spectral detail offers an unmatched fingerprinting capability that can, for example, identify the spin and oxidation states of heme groups [1] and distinguish among the variety of iron-sulfur centers found in biological molecules [18][19][20].Metalloprotein MCD can be measured at ambient or cryogenic temperatures. The latter requires adulteration with glassing agents [16] but has generally been preferred because MCD intensity from paramagnetic centers increases dramatically at low temperature. Thus, most metalloprotein MCD reported has been measured in glasses at temperatures of approximately 4.2 K. Hemoproteins represent the significant exception, giving rise to appreciable MCD at high temperatures [1]. Thus, ambient temperature MCD is used to diagnose spin state, oxidation state, and (in the case of low-spin Fe(III) hemes) axial ligation [21].As ...

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“…Reduced cytochrome C was quantitated using an extinction coefficient of 21.1 mM-' cm-' at 550 nm (reduced-oxidized) (25). Specificity of cytochrome C reduction was verified by adding 0.7 ml of 150 pghl superoxide dismutase (Bovine, Sigma Chemical Company, St. Louis, MO) to the reaction mixture at the same time as the serum and proceeding as above.…”

Section: Superoxide ( 0 2 -Assay)mentioning

confidence: 99%

Increased endothelial cell adherence, aggregation, and superoxide generation by neutrophils incubated in systemic lupus erythematosus and felty's syndrome sera

Hashimoto

Ziff

Hurd

1982

Arthritis & Rheumatism

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The ability of sera from patients with systemic lupus erythematosus (SLE) and Felty's syndrome to induce increased adhesiveness of normal human neutrophils (PMN) was investigated. PMN from normal healthy donors were incubated in sera from 19 patients with active SLE, 12 with inactive SLE, 20 with Felty's, 24 with rheumatoid arthritis, and 34 normal persons. After incubation, the degree of adherence of the PMN to human endothelial cells in culture, their aggregation, and superoxide (O2‐) generation were determined. Sera from patients with both active SLE and Felty's syndrome induced significantly increased PMN adherence to endothelial cells and PMN aggregation in vitro, compared with normal sera. This increased adherence to endothelial cells was maintained after heat treatment (56°C for 30 minutes) of the sera. In O2‐ generation experiments, sera from patients with active SLE induced significantly increased O2‐ release from normal PMN using both fresh and heat‐treated sera. Sera from Felty's patients demonstrated the same effect with heattreated sera but not with fresh sera. When sera from patients with active SLE and Felty's syndrome were used, all three parameters correlated significantly with each other in individual patients. In contrast, sera from the 12 patients with inactive SLE and 24 rheumatoid arthritis patients without Felty's failed to induce significant differences in the three parameters studied when compared with 34 normal controls. Fractionation of 3 SLE sera and 1 Felty's serum on Sephadex G‐200 demonstrated that the adherence enhancing factor was present in both IgG and IgG‐excluded fractions. The observed increased adhesiveness of PMN induced by SLE and Felty's sera may, at least in part, contribute to the neutropenia which is common in these diseases. Increased O2‐ release associated with PMN adherence may contribute to endothelial cell damage and vascular injury, which is also a common manifestation of these diseases.

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The extinction coefficient of cytochrome c

Cited by 673 publications

References 9 publications

The pre-steady state reaction of ferrocytochrome c with the cytochrome c-cytochrome aa3 complex

The pre-steady state reaction of ferrocytochrome c with the cytochrome c-cytochrome aa3 complex

Probing a Complex of Cytochromecand Cardiolipin by Magnetic Circular Dichroism Spectroscopy: Implications for the Initial Events in Apoptosis

Increased endothelial cell adherence, aggregation, and superoxide generation by neutrophils incubated in systemic lupus erythematosus and felty's syndrome sera

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