Related Articles13C-NMR studies of transmembrane electron transfer to extracellular ferricyanide in human erythrocytes.
Eur J Biochem. 1997 Jun 15;246(3):638-45
Authors: Himmelreich U, Kuchel PW
Human erythrocytes are known to reduce ferricyanide (hexacyanoferrate) [Fe(CN)6]3- to ferrocyanide [Fe(CN)6]2- in an extracellular reaction that involves the transmembrane transfer of reducing equivalents; potentially these could be either electrons from NADH, formed in glycolysis inside the cells or transmembrane exchange of reduced solutes. The 13C-NMR resonance of [Fe(13CN)6]3- (which was synthesised in our laboratory) was seen to be very broad while that of ferrocyanide was narrow. This phenomenon formed the basis of a simple non-invasive procedure to study ferricyanide reduction in high-haematocrit suspensions of erythrocytes. The method should be directly applicable to other cell types. In a series of experiments, erythrocyte metabolism was studied in the presence of ferricyanide, using 1H, 13C, and 31P NMR spectroscopy. Incubating the cells with 13C-labelled glucose enabled the rate of ferricyanide reduction, glucose utilisation, and lactate and bicarbonate production to be measured simultaneously. Various metabolic states were imposed as follows: glycolysis was inhibited with F- and iodoacetate; glucose transport was inhibited with phloretin and cytochalasin B; and anion transport was inhibited with dinitrostilbene 2,2'-disulfonate and p-chloromercuriphenyl sulfonate. Earlier work was confirmed, showing that ascorbate is intimately involved in the reduction reaction; but its main action appears not to be mediated by membrane transport but in a membrane-associated redox-protein complex that is functionally linked to glycolysis. Also, large differences (factors of three) in the rate of the reduction reaction were recorded in erythrocytes from different, apparently healthy, donors.
Effect of Freezing Conditions on Distances and Their Distributions Derived from Double Electron Electron Resonance (DEER): A Study of Doubly-Spin-Labeled T4 Lysozyme
Effect of Freezing Conditions on Distances and Their Distributions Derived from Double Electron Electron Resonance (DEER): A Study of Doubly-Spin-Labeled T4 Lysozyme
Publication year: 2012
Source: Journal of Magnetic Resonance, Available online 24 January 2012</br>
Elka R.*Georgieva, Aritro S.*Roy, Vladimir M.*Grigoryants, Petr P.*Borbat, Keith A.*Earle, ...</br>
Pulsed dipolar ESR spectroscopy, DEER and DQC, require frozen samples. An important issue in the biological application of this technique is how the freezing rate and concentration of cryoprotectant could possibly affect the...
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01-25-2012 08:56 AM
NMR basis for interprotein electron transfer gating between cytochrome c and cytochrome c oxidase [Biochemistry]
NMR basis for interprotein electron transfer gating between cytochrome c and cytochrome c oxidase
Sakamoto, K., Kamiya, M., Imai, M., Shinzawa-Itoh, K., Uchida, T., Kawano, K., Yoshikawa, S., Ishimori, K....
Date: 2011-07-26
The final interprotein electron transfer (ET) in the mammalian respiratory chain, from cytochrome c (Cyt c) to cytochrome c oxidase (CcO) is investigated by 1H-15N heteronuclear single quantum coherence spectral analysis. The chemical shift perturbation in isotope-labeled Cyt c induced by addition of unlabeled CcO indicates that the hydrophobic heme periphery and...
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Choosing membrane mimetics for NMR structural studies of transmembrane proteins.
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Biochim Biophys Acta. 2011 Apr 5;
Authors: Warschawski DE, Arnold AA, Beaugrand M, Gravel A, Chartrand E, Marcotte I
The native environment of membrane proteins is complex and scientists have felt the need to simplify it to reduce the number of varying parameters. However, experimental problems can also arise from oversimplification which contributes to why membrane proteins are...
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04-12-2011 11:08 AM
[NMR paper] Gated electron transfers and electron pathways in azurin: a NMR dynamic study at mult
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Authors: Zhuravleva AV, Korzhnev DM, Kupce E, Arseniev AS, Billeter M, Orekhov VY
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Biochemistry. 2001 Apr 17;40(15):4859-66
Authors: Birdsall B, Feeney J, Burdett ID, Bawumia S, Barboni EA, Hughes RC
Galectin-3, a beta-galactoside binding protein, contains a...
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Eur J Biochem. 1998 Jul 1;255(1):125-32
Authors: Griffin KJ, Degala GD, Eisenreich W, Müller F, Bacher A, Frerman FE
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[NMR paper] 13C-NMR studies of transmembrane electron transfer to extracellular ferricyanide in h
13C-NMR studies of transmembrane electron transfer to extracellular ferricyanide in human erythrocytes.
http://www.ncbi.nlm.nih.gov/corehtml/query/egifs/http:--www3.interscience.wiley.com-aboutus-images-wiley_interscience_pubmed_logo_FREE_120x27.gif Related Articles 13C-NMR studies of transmembrane electron transfer to extracellular ferricyanide in human erythrocytes.
Eur J Biochem. 1997 Jun 15;246(3):638-45
Authors: Himmelreich U, Kuchel PW
Human erythrocytes are known to reduce ferricyanide (hexacyanoferrate) 3- to ferrocyanide 2- in an...