PMID- 20599734
OWN - NLM
STAT- MEDLINE
DCOM- 20100809
LR  - 20100726
IS  - 1090-2104 (Electronic)
IS  - 0006-291X (Linking)
VI  - 398
IP  - 2
DP  - 2010 Jul 23
TI  - Redox-controlled backbone dynamics of human cytochrome c revealed by 15N NMR 
      relaxation measurements.
PG  - 231-6
LID - 10.1016/j.bbrc.2010.06.065 [doi]
AB  - Redox-controlled backbone dynamics in cytochrome c (Cyt c) were revealed by 2D 
      15N NMR relaxation experiments. 15N T1 and T2 values and 1H-15N NOEs of uniformly 
      15N-labeled reduced and oxidized Cyt c were measured, and the generalized order 
      parameters (S2), the effective correlation time for internal motion (taue), the 
      15N exchange broadening contributions (Rex) for each residue, and the overall 
      correlation time (taum) were estimated by model-free dynamics formalism. These 
      dynamic parameters clearly showed that the backbone dynamics of Cyt c are highly 
      restricted due to the covalently bound heme that functions as the stable 
      hydrophobic core. Upon oxidation of the heme iron in Cyt c, the average S2 value 
      was increased from 0.88+/-0.01 to 0.92+/-0.01, demonstrating that the mobility of 
      the backbone is further restricted in the oxidized form. Such increases in the S2 
      values were more prominent in the loop regions, including amino acid residues 
      near the thioether bonds to the heme moiety and positively charged region around 
      Lys87. Both of the regions are supposed to form the interaction site for 
      cytochrome c oxidase (CcO) and the electron pathway from Cyt c to CcO. The 
      redox-dependent mobility of the backbone in the interaction site for the electron 
      transfer to CcO suggests an electron transfer mechanism regulated by the backbone 
      dynamics in the Cyt c-CcO system.
CI  - Copyright (c) 2010 Elsevier Inc. All rights reserved.
FAU - Sakamoto, Koichi
AU  - Sakamoto K
AD  - Division of Chemistry, Graduate School of Science, Hokkaido University, Sapporo 
      060-0810, Japan.
FAU - Kamiya, Masakatsu
AU  - Kamiya M
FAU - Uchida, Takeshi
AU  - Uchida T
FAU - Kawano, Keiichi
AU  - Kawano K
FAU - Ishimori, Koichiro
AU  - Ishimori K
LA  - eng
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
DEP - 20100619
PL  - United States
TA  - Biochem Biophys Res Commun
JT  - Biochemical and biophysical research communications
JID - 0372516
RN  - 0 (Nitrogen Isotopes)
RN  - 9007-43-6 (Cytochromes c)
RN  - EC 1.9.3.1 (Electron Transport Complex IV)
SB  - IM
MH  - Cytochromes c/*metabolism
MH  - Electron Transport Complex IV/*metabolism
MH  - Humans
MH  - Nitrogen Isotopes
MH  - Nuclear Magnetic Resonance, Biomolecular
MH  - Oxidation-Reduction
EDAT- 2010/07/06 06:00
MHDA- 2010/08/10 06:00
CRDT- 2010/07/06 06:00
PHST- 2010/06/08 00:00 [received]
PHST- 2010/06/16 00:00 [accepted]
PHST- 2010/07/06 06:00 [entrez]
PHST- 2010/07/06 06:00 [pubmed]
PHST- 2010/08/10 06:00 [medline]
AID - S0006-291X(10)01191-5 [pii]
AID - 10.1016/j.bbrc.2010.06.065 [doi]
PST - ppublish
SO  - Biochem Biophys Res Commun. 2010 Jul 23;398(2):231-6. doi: 
      10.1016/j.bbrc.2010.06.065. Epub 2010 Jun 19.