PMID- 16566602
OWN - NLM
STAT- MEDLINE
DCOM- 20060516
LR  - 20131121
IS  - 0006-2960 (Print)
IS  - 0006-2960 (Linking)
VI  - 45
IP  - 13
DP  - 2006 Apr 4
TI  - Influence of reduction of heme a and Cu(A) on the oxidized catalytic center of 
      cytochrome c oxidase: insight from organic solvents.
PG  - 4277-83
AB  - Purified bovine heart cytochrome c oxidase (CcO) has been extracted from aqueous 
      solution into hexane in the presence of phospholipids and calcium ions. In 
      extracts, CcO is in the so-called "slow" form and probably situated in reverse 
      micelles. At low water:phospholipid molar ratios, electron transfer from reduced 
      heme a and Cu(A) to the catalytic center is inhibited and both heme a3 and Cu(B) 
      remain in the oxidized state. The rate of binding of cyanide to heme a3 in this 
      oxidized catalytic center is, however, dependent on the redox state of heme a and 
      Cu(A). When heme a and Cu(A) are reduced, the rate is increased 20-fold compared 
      to the rate when these two centers are oxidized. The enhanced rate of binding of 
      cyanide to heme a3 is explained by the destabilization of an intrinsic ligand, 
      located at the catalytic site, that is triggered by the reduction of heme a and 
      Cu(A).
FAU - Fabian, Marian
AU  - Fabian M
AD  - Department of Biochemistry and Cell Biology, MS 140, Rice University, Houston, 
      Texas 77005, USA. fabian@rice.edu
FAU - Jancura, Daniel
AU  - Jancura D
FAU - Bona, Martin
AU  - Bona M
FAU - Musatov, Andrej
AU  - Musatov A
FAU - Baran, Miroslav
AU  - Baran M
FAU - Palmer, Graham
AU  - Palmer G
LA  - eng
GR  - GM 55807/GM/NIGMS NIH HHS/United States
PT  - Journal Article
PT  - Research Support, N.I.H., Extramural
PT  - Research Support, Non-U.S. Gov't
PL  - United States
TA  - Biochemistry
JT  - Biochemistry
JID - 0370623
RN  - 0 (Hexanes)
RN  - 0 (Micelles)
RN  - 0 (Phosphatidylcholines)
RN  - 0 (Phospholipids)
RN  - 0 (Solvents)
RN  - 18535-39-2 (heme a)
RN  - 42VZT0U6YR (Heme)
RN  - 69279-91-0 (asolectin)
RN  - 789U1901C5 (Copper)
RN  - EC 1.9.3.1 (Electron Transport Complex IV)
RN  - O5DDB9Z95G (Sodium Cyanide)
SB  - IM
MH  - Animals
MH  - Cattle
MH  - Copper/*chemistry
MH  - Electron Spin Resonance Spectroscopy
MH  - Electron Transport Complex IV/antagonists & inhibitors/*chemistry
MH  - Heme/*analogs & derivatives/chemistry
MH  - Hexanes
MH  - Kinetics
MH  - Micelles
MH  - Myocardium/enzymology
MH  - Oxidation-Reduction
MH  - Phosphatidylcholines
MH  - Phospholipids
MH  - Sodium Cyanide/chemistry
MH  - Solvents
EDAT- 2006/03/29 09:00
MHDA- 2006/05/17 09:00
CRDT- 2006/03/29 09:00
PHST- 2006/03/29 09:00 [pubmed]
PHST- 2006/05/17 09:00 [medline]
PHST- 2006/03/29 09:00 [entrez]
AID - 10.1021/bi052632+ [doi]
PST - ppublish
SO  - Biochemistry. 2006 Apr 4;45(13):4277-83. doi: 10.1021/bi052632+.