Related ArticlesCharacterisation of the electron self-exchange rates in hexametaphosphate-cytochrome-c aggregates measured using high-resolution 1H-NMR spectroscopy.
Eur J Biochem. 1991 Aug 1;199(3):553-60
Authors: Concar DW, Whitford D, Williams RJ
1H-NMR spectroscopy has been used to measure the rate of unimolecular electron exchange between cytochrome c molecules in protein aggregates stabilised by the addition of sodium hexametaphosphate. The average intracomplex electron exchange rate is measured from line broadening of hyperfine-shifted resonances of ferricytochrome c in an equimolar mixture of reduced and oxidised protein. The line-broadening due to electron exchange is significantly greater than that due to protein aggregation and reaches a maximum value between 1-2 mol hexametaphosphate/mol protein. Significantly the exchange-induced broadening is a first-order process and is directly proportional to the size of the cytochrome c oligomer. From the temperature dependence of exchange broadening the activation enthalpy was estimated to be 75.8 kJ mol-1 whereas the activation entropy was 295 J mol-1 K-1 for a dimer of cytochrome c at a hexametaphosphate/protein molar ratio of 1. Both activation parameters decrease in magnitude as the order of the cytochrome c oligomer increases. The rates of intracomplex electron exchange in Saccharomyces cerevisiae iso-2 and Candida krusei cytochromes c are lower than that of the horse protein, implying that primary sequence plays a fundamental part in determining the rate of exchange. The relevance of these observations is discussed in terms of the function of cytochrome c.
Measurement of amide hydrogen exchange rates with the use of radiation damping
Measurement of amide hydrogen exchange rates with the use of radiation damping
Abstract A simple method for measuring amide hydrogen exchange rates is presented, which is based on the selective inversion of water magnetization with the use of radiation damping. Simulations show that accurate exchange rates can be measured despite the complications of radiation damping and cross relaxation to the exchange process between amide and water protons. This method cannot eliminate the contributions of the exchange-relayed NOE and direct NOE to the measured exchange rates, but minimize the...
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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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[NMR paper] Determination of the electron relaxation rates in paramagnetic metal complexes: appli
Determination of the electron relaxation rates in paramagnetic metal complexes: applicability of available NMR methods.
Related Articles Determination of the electron relaxation rates in paramagnetic metal complexes: applicability of available NMR methods.
J Magn Reson. 2004 Apr;167(2):169-77
Authors: Jensen MR, Led JJ
Four different approaches for determining the electron relaxation rates in paramagnetic metallo-proteins are investigated, using a paramagnetic Ni2+ complex of a protein as an example. All four approaches rely on the...
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[NMR paper] A general method for determining the electron self-exchange rates of blue copper prot
A general method for determining the electron self-exchange rates of blue copper proteins by longitudinal NMR relaxation.
Related Articles A general method for determining the electron self-exchange rates of blue copper proteins by longitudinal NMR relaxation.
J Am Chem Soc. 2002 Apr 17;124(15):4093-6
Authors: Jensen MR, Hansen DF, Led JJ
A general NMR method is presented that allows a precise determination of the second-order rate constant, k(ese), for the electron self-exchange in blue copper proteins, from the longitudinal relaxation...
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[NMR paper] Stopped-flow NMR measurement of hydrogen exchange rates in reduced horse cytochrome c
Stopped-flow NMR measurement of hydrogen exchange rates in reduced horse cytochrome c under strongly destabilizing conditions.
Related Articles Stopped-flow NMR measurement of hydrogen exchange rates in reduced horse cytochrome c under strongly destabilizing conditions.
Proteins. 1998 Aug 1;32(2):241-7
Authors: Bhuyan AK, Udgaonkar JB
A procedure to measure exchange rates of fast exchanging protein amide hydrogens by time-resolved NMR spectroscopy following in situ initiation of the reaction by diluting a native protein solution into an...
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Quantification of protein backbone hydrogen-deuterium exchange rates by solid state N
Quantification of protein backbone hydrogen-deuterium exchange rates by solid state NMR spectroscopy
Abstract We present the quantification of backbone amide hydrogen-deuterium exchange rates (HDX) for immobilized proteins. The experiments make use of the deuterium isotope effect on the amide nitrogen chemical shift, as well as on proton dilution by deuteration. We find that backbone amides in the microcrystalline α-spectrin SH3 domain exchange rather slowly with the solvent (with exchange rates negligible within the individual 15Nâ??T 1 timescales). We observed chemical exchange for 6...
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[NMR paper] Characterisation of the electron self-exchange rates in hexametaphosphate-cytochrome-
Characterisation of the electron self-exchange rates in hexametaphosphate-cytochrome-c aggregates measured using high-resolution 1H-NMR spectroscopy.
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 Characterisation of the electron self-exchange rates in hexametaphosphate-cytochrome-c aggregates measured using high-resolution 1H-NMR spectroscopy.
Eur J Biochem. 1991 Aug 1;199(3):553-60
Authors: Concar DW, Whitford D, Williams RJ
...
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08-21-2010 11:12 PM
15NH/D-SOLEXSY experiment for accurate measurement of amide solvent exchange rates: a
Abstract Amide solvent exchange rates are regarded as a valuable source of information on structure/dynamics of unfolded (disordered) proteins. Proton-based saturation transfer experiments, normally used to measure solvent exchange, are known to meet some serious difficulties. The problems mainly arise from the need to (1) manipulate water magnetization and (2) discriminate between multiple magnetization transfer pathways that occur within the proton pool. Some of these issues are specific to unfolded proteins. For example, the compensation scheme used to cancel the Overhauser effect in the...
Characterisation of the electron self-exchange rates in hexametaphosphate-cytochrome-
Linear Mode
