Hydrogen exchange and two-dimensional nuclear magnetic resonance (2D NMR) techniques were used to characterize the structure of oxidized horse cytochrome c at acid pH and high ionic strength. Under these conditions, cytochrome c is known to assume a globular conformation (A state) with properties resembling those of the molten globule state described for other proteins. In order to measure the rate of hydrogen-deuterium exchange for individual backbone amide protons in the A state, samples of oxidized cytochrome c were incubated at 20 degrees C in D2O buffer (pD 2.2, 1.5 M NaCl) for time periods ranging from 2 min to 500 h. The exchange reaction was then quenched by transferring the protein to native conditions (pD 5.3). The extent of exchange for 44 amide protons trapped in the refolded protein was measured by 2D NMR spectroscopy. The results show that this approach can provide detailed information on H-bonded secondary and tertiary structure in partially folded equilibrium forms of a protein. All of the slowly exchanging amide protons in the three major helices of native cytochrome c are strongly protected from exchange at acid pH, indicating that the A state contains native-like elements of helical secondary structure. By contrast, a number of amide protons involved in irregular tertiary H-bonds of the native structure (Gly37, Arg38, Gln42, Ile57, Lys79, and Met80) are only marginally protected in the A state, indicating that these H-bonds are unstable or absent. The H-exchange results suggest that the major helices of cytochrome c and their common hydrophobic domain are largely preserved in the globular acidic form while the loop region of the native structure is flexible and partly disordered.
[NMR paper] NMR-detected hydrogen exchange and molecular dynamics simulations provide structural
NMR-detected hydrogen exchange and molecular dynamics simulations provide structural insight into fibril formation of prion protein fragment 106-126.
Related Articles NMR-detected hydrogen exchange and molecular dynamics simulations provide structural insight into fibril formation of prion protein fragment 106-126.
Proc Natl Acad Sci U S A. 2003 Dec 9;100(25):14790-5
Authors: Kuwata K, Matumoto T, Cheng H, Nagayama K, James TL, Roder H
PrP106-126, a peptide corresponding to residues 107-127 of the human prion protein, induces neuronal cell...
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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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[NMR paper] NMR assignments for acid-denatured cold shock protein A.
NMR assignments for acid-denatured cold shock protein A.
Related Articles NMR assignments for acid-denatured cold shock protein A.
J Biomol NMR. 1998 May;11(4):461-2
Authors: Alexandrescu AT, Rathgeb-Szabo K
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[NMR paper] Hydrogen exchange properties of proteins in native and denatured states monitored by
Hydrogen exchange properties of proteins in native and denatured states monitored by mass spectrometry and NMR.
http://www.ncbi.nlm.nih.gov/corehtml/query/egifs/http:--www3.interscience.wiley.com-aboutus-images-wiley_interscience_pubmed_logo_FREE_120x27.gif http://www.ncbi.nlm.nih.gov/corehtml/query/egifs/http:--www.pubmedcentral.nih.gov-corehtml-pmc-pmcgifs-pubmed-pmc.gif Related Articles Hydrogen exchange properties of proteins in native and denatured states monitored by mass spectrometry and NMR.
Protein Sci. 1997 Jun;6(6):1316-24
Authors: Chung EW,...
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[NMR paper] Hydrogen exchange properties of proteins in native and denatured states monitored by
Hydrogen exchange properties of proteins in native and denatured states monitored by mass spectrometry and NMR.
http://www.ncbi.nlm.nih.gov/corehtml/query/egifs/http:--www3.interscience.wiley.com-aboutus-images-wiley_interscience_pubmed_logo_FREE_120x27.gif http://www.ncbi.nlm.nih.gov/corehtml/query/egifs/http:--www.pubmedcentral.nih.gov-corehtml-pmc-pmcgifs-pubmed-pmc.gif Related Articles Hydrogen exchange properties of proteins in native and denatured states monitored by mass spectrometry and NMR.
Protein Sci. 1997 Jun;6(6):1316-24
Authors: Chung EW,...
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[NMR paper] The methanol-induced globular and expanded denatured states of cytochrome c: a study
The methanol-induced globular and expanded denatured states of cytochrome c: a study by CD fluorescence, NMR and small-angle X-ray scattering.
http://www.ncbi.nlm.nih.gov/corehtml/query/egifs/http:--linkinghub.elsevier.com-ihub-images-PubMedLink.gif Related Articles The methanol-induced globular and expanded denatured states of cytochrome c: a study by CD fluorescence, NMR and small-angle X-ray scattering.
J Mol Biol. 1996 Jun 14;259(3):512-23
Authors: Kamatari YO, Konno T, Kataoka M, Akasaka K
Methanol-induced conformational transitions of...
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[NMR paper] An antibody binding site on cytochrome c defined by hydrogen exchange and two-dimensi
An antibody binding site on cytochrome c defined by hydrogen exchange and two-dimensional NMR.
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Science. 1990 Aug 17;249(4970):755-9
Authors: Paterson Y, Englander SW, Roder H
The interaction of a protein antigen, horse cytochrome c (cyt c), with a monoclonal antibody has been studied by hydrogen-deuterium (H-D) exchange labeling and two-dimensional nuclear magnetic resonance (2D NMR) methods. The H-exchange rate of residues in three...
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[NMR paper] Denatured states of human carbonic anhydrase II: an NMR study of hydrogen/deuterium e
Denatured states of human carbonic anhydrase II: an NMR study of hydrogen/deuterium exchange at tryptophan-indole-H(N) sites.
http://www.ncbi.nlm.nih.gov/corehtml/query/egifs/http:--linkinghub.elsevier.com-ihub-images-PubMedLink.gif Related Articles Denatured states of human carbonic anhydrase II: an NMR study of hydrogen/deuterium exchange at tryptophan-indole-H(N) sites.
FEBS Lett. 1999 Feb 26;445(2-3):361-5
Authors: Jonasson P, Kjellsson A, Sethson I, Jonsson BH
Hydrogen/deuterium (H/D) exchange measurements in low and moderate...