PMID- 21746907
OWN - NLM
STAT- MEDLINE
DCOM- 20111003
LR  - 20211020
IS  - 1091-6490 (Electronic)
IS  - 0027-8424 (Print)
IS  - 0027-8424 (Linking)
VI  - 108
IP  - 30
DP  - 2011 Jul 26
TI  - NMR basis for interprotein electron transfer gating between cytochrome c and 
      cytochrome c oxidase.
PG  - 12271-6
LID - 10.1073/pnas.1108320108 [doi]
AB  - The final interprotein electron transfer (ET) in the mammalian respiratory chain, 
      from cytochrome c (Cyt c) to cytochrome c oxidase (CcO) is investigated by 
      (1)H-(15)N 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 adjacent hydrophobic amino acid 
      residues of Cyt c dominantly contribute to the complex formation, whereas charged 
      residues near the hydrophobic core refine the orientation of Cyt c to provide 
      well controlled ET. Upon oxidation of Cyt c, the specific line broadening of N-H 
      signals disappeared and high field (1)H chemical shifts of the N-terminal helix 
      were observed, suggesting that the interactions of the N-terminal helix with CcO 
      are reduced by steric constraint in oxidized Cyt c, while the chemical shift 
      perturbations in the C-terminal helix indicate notable interactions of oxidized 
      Cyt c with CcO. These results suggest that the overall affinity of oxidized Cyt c 
      for CcO is significantly, but not very much weaker than that of reduced Cyt c. 
      Thus, electron transfer is gated by dissociation of oxidized Cyt c from CcO, the 
      rate of which is controlled by the affinity of oxidized Cyt c to CcO for 
      providing an appropriate electron transfer rate for the most effective energy 
      coupling. The conformational changes in Lys13 upon CcO binding to oxidized Cyt c, 
      shown by (1)H- and (1)H, (15)N-chemical shifts, are also expected to gate 
      intraprotein ET by a polarity control of heme c environment.
FAU - Sakamoto, Koichi
AU  - Sakamoto K
AD  - Hokkaido University, Sapporo, Japan.
FAU - Kamiya, Masakatsu
AU  - Kamiya M
FAU - Imai, Mizue
AU  - Imai M
FAU - Shinzawa-Itoh, Kyoko
AU  - Shinzawa-Itoh K
FAU - Uchida, Takeshi
AU  - Uchida T
FAU - Kawano, Keiichi
AU  - Kawano K
FAU - Yoshikawa, Shinya
AU  - Yoshikawa S
FAU - Ishimori, Koichiro
AU  - Ishimori K
LA  - eng
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
DEP - 20110711
PL  - United States
TA  - Proc Natl Acad Sci U S A
JT  - Proceedings of the National Academy of Sciences of the United States of America
JID - 7505876
RN  - 0 (Recombinant Proteins)
RN  - 9007-43-6 (Cytochromes c)
RN  - EC 1.9.3.1 (Electron Transport Complex IV)
SB  - IM
MH  - Animals
MH  - Binding Sites
MH  - Cattle
MH  - Cytochromes c/*chemistry/*metabolism
MH  - Electron Transport
MH  - Electron Transport Complex IV/*chemistry/*metabolism
MH  - Humans
MH  - In Vitro Techniques
MH  - Models, Molecular
MH  - Nuclear Magnetic Resonance, Biomolecular
MH  - Oxidation-Reduction
MH  - Protein Interaction Domains and Motifs
MH  - Protein Structure, Secondary
MH  - Recombinant Proteins/chemistry/metabolism
PMC - PMC3145682
COIS- The authors declare no conflict of interest.
EDAT- 2011/07/13 06:00
MHDA- 2011/10/04 06:00
PMCR- 2012/01/26
CRDT- 2011/07/13 06:00
PHST- 2011/07/13 06:00 [entrez]
PHST- 2011/07/13 06:00 [pubmed]
PHST- 2011/10/04 06:00 [medline]
PHST- 2012/01/26 00:00 [pmc-release]
AID - 1108320108 [pii]
AID - 201108320 [pii]
AID - 10.1073/pnas.1108320108 [doi]
PST - ppublish
SO  - Proc Natl Acad Sci U S A. 2011 Jul 26;108(30):12271-6. doi: 
      10.1073/pnas.1108320108. Epub 2011 Jul 11.