Optical activity of hemoproteins in the Soret region. Circular dichroism of the heme undecapeptide of cytochrome c in aqueous solution

Blauer, G.; Sreerama, Narasimha; Woody, Robert W.

doi:10.1021/bi00077a021

Cited by 131 publications

(112 citation statements)

References 36 publications

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“…This suggests that the two proteins have similar but not identical heme pocket structures. In hemoproteins, the Soret CD spectrum is strictly correlated with the heme pocket conformation [24]. In particular, for cyt c the 416-nm Cotton effect is associated to the F82-and M80-heme interaction and is considered a probe of the environment on the M80 side of the heme pocket in the native protein [25,26].…”

Section: Ferric Cyt Cmentioning

confidence: 99%

The effects of ATP and sodium chloride on the cytochrome c–cardiolipin interaction: The contrasting behavior of the horse heart and yeast proteins

Sinibaldi¹,

Droghetti²,

Polticelli³

et al. 2011

Journal of Inorganic Biochemistry

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In cells a portion of cytochrome c (cyt c) (15-20%) is tightly bound to cardiolipin (CL), one of the phospholipids constituting the mitochondrial membrane. The CL-bound protein, which has nonnative tertiary structure, altered heme pocket, and disrupted Fe(III)-M80 axial bond, is thought to play a role in the apoptotic process. This has attracted considerable interest in order to clarify the mechanisms governing the cyt c-CL interaction. Herein we have investigated the binding reaction of CL with the c-type cytochromes from horse heart and yeast. Although the two proteins possess a similar tertiary architecture, yeast cyt c displays lower stability and, contrary to the equine protein, it does not bind ATP and lacks pro-apoptotic activity. The study has been performed in the absence and in the presence of ATP and NaCl, two compounds that influence the (horse cyt c)-CL binding process and, thus, the pro-apoptotic activity of the protein. The two proteins behave differently: while CL interaction with horse cyt c is strongly influenced by the two effectors, no effect is observed for yeast cyt c. It is noteworthy that NaCl induces dissociation of the (horse cyt c)-CL complex but has no influence on that of yeast cyt c. The differences found for the two proteins highlight that specific structural factors, such as the different local structure conformation of the regions involved in the interactions with either CL or ATP, can significantly affect the behavior of cyt c in its reaction with liposomes and the subsequent pro-apoptotic action of the protein.

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Section: Ferric Cyt Cmentioning

confidence: 99%

The effects of ATP and sodium chloride on the cytochrome c–cardiolipin interaction: The contrasting behavior of the horse heart and yeast proteins

Sinibaldi¹,

Droghetti²,

Polticelli³

et al. 2011

Journal of Inorganic Biochemistry

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“…Nevertheless, CD spectra of this region are strongly dependent on the immediate conformational environment of the heme group and provide a sensitive indicator of small scale conformational changes in the protein (45). Denaturation studies have indicated that the trough at 420 nm relates to the heme iron-Met (80) bond in cyt c (46).…”

Section: Effects Of Atp On the Binding Of Cyt C To Liposomes-atmentioning

confidence: 99%

ATP Induces a Conformational Change in Lipid-bound Cytochrome c

Tuominen

Zhu

Wallace

et al. 2001

Journal of Biological Chemistry

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“…4). FAD optical activity is induced by dipole-dipole interactions of the flavin with the ribityl side chain, the peptide backbone, and side-chains of tyrosine, tryptophan, and to a lesser extent, methionine (28,29). The ␣T266M ETF circular dichroism spectrum reflects the loss of resolution in the visible absorption spectrum.…”

Section: Expression and Stabilization Of Mutants-initial Attempts Tomentioning

confidence: 99%

Expression and Characterization of Two Pathogenic Mutations in Human Electron Transfer Flavoprotein

Salazar

Zhang

Degala

et al. 1997

Journal of Biological Chemistry

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Defects in electron transfer flavoprotein (ETF) or its electron acceptor, electron transfer flavoproteinubiquinone oxidoreductase (ETF-QO), cause the human inherited metabolic disease glutaric acidemia type II. In this disease, electron transfer from nine primary flavoprotein dehydrogenases to the main respiratory chain is impaired. Among these dehydrogenases are the four chain length-specific flavoprotein dehydrogenases of fatty acid ␤-oxidation. In this investigation, two mutations in the ␣ subunit that have been identified in patients were expressed in Escherichia coli. Of the two mutant alleles, ␣T266M and ␣G116R, the former is the most frequent mutation found in patients with ETF deficiency. The crystal structure of human ETF shows that ␣G116 lies in a hydrophobic pocket, under a contact residue of the ␣/␤ subunit interface, and that the hydroxyl hydrogen of ␣T266 is hydrogen Stable expression of the ␣G116R ETF required coexpression of the chaperonins, GroEL and GroES. ␣G116R ETF folds into a conformation different from the wild type, and is catalytically inactive in crude extracts. It is unstable and could not be extensively purified. The ␣T266M ETF was purified and characterized after stabilization to proteolysis in crude extracts. Although the global structure of this mutant protein is unchanged, its flavin environment is altered as indicated by absorption and circular dichroism spectroscopy and the kinetics of flavin release from the oxidized and reduced protein.The loss of the hydrogen bond at N(5) of the flavin and the altered flavin binding increase the thermodynamic stability of the flavin semiquinone by 10-fold relative to the semiquinone of wild type ETF. The mutation has relatively little effect on the reductive half-reaction of ETF catalyzed by sarcosine and medium chain acyl-CoA dehydrogenases which reduce the flavin to the semiquinone. However, k cat /K m of ETF-QO in a coupled acylCoA:ubiquinone reductase assay with oxidized ␣T266M ETF as substrate is reduced 33-fold; this decrease is due in largest part to a decrease in the rate of disproportionation of the ␣T266M ETF semiquinone catalyzed by ETF-QO. Electron transfer flavoproteins (ETF)1 are heterodimeric, FAD-containing proteins that transfer electrons between primary dehydrogenases and respiratory chains in eukaryotic and prokaryotic cells. In mammalian systems, ETF transfers electrons from nine mitochondrial flavoprotein dehydrogenases to the main respiratory chain via the iron-sulfur flavoprotein, ETF-ubiquinone oxidoreductase (ETF-QO) (1). Porcine ETF is apparently closely related to human ETF (2, 3). Both proteins stabilize an anionic flavin semiquinone upon reduction by the flavoprotein dehydrogenases (4, 5). Reduction of ETF to the hydroquinone oxidation state by the dehydrogenases is very slow and not kinetically significant (4, 6). However, kinetic studies of the ETF-QO-catalyzed reduction of ubiquinone by reduced ETF by Ramsay et al. indicated that ETF hydroquinone, and not the semiquinone, is the reductant of ubiquinone (6). Thi...

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Optical activity of hemoproteins in the Soret region. Circular dichroism of the heme undecapeptide of cytochrome c in aqueous solution

Cited by 131 publications

References 36 publications

The effects of ATP and sodium chloride on the cytochrome c–cardiolipin interaction: The contrasting behavior of the horse heart and yeast proteins

The effects of ATP and sodium chloride on the cytochrome c–cardiolipin interaction: The contrasting behavior of the horse heart and yeast proteins

ATP Induces a Conformational Change in Lipid-bound Cytochrome c

Expression and Characterization of Two Pathogenic Mutations in Human Electron Transfer Flavoprotein

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