PMID- 29635042
OWN - NLM
STAT- MEDLINE
DCOM- 20180924
LR  - 20180924
IS  - 1638-6183 (Electronic)
IS  - 0300-9084 (Linking)
VI  - 149
DP  - 2018 Jun
TI  - Effect of Ca(2+) on the redox potential of heme a in cytochrome c oxidase.
PG  - 71-78
LID - S0300-9084(18)30091-9 [pii]
LID - 10.1016/j.biochi.2018.04.005 [doi]
AB  - Subunit I of cytochrome c oxidase (CcO) from mitochondria and many bacteria 
      contains a cation binding site (CBS) located at the outer positively charged 
      aqueous phase not far from heme a. Binding of Ca(2+) with the CBS in bovine CcO 
      inhibits activity of the enzyme 2-3 -fold [Vygodina, T., Kirichenko, A. & 
      Konstantinov A.A. (2013) Direct Regulation of Cytochrome c Oxidase by Calcium 
      Ions, PLoS One.8 e74436]. Here we show that binding of Ca(2+) at CBS of bovine 
      CcO shifts E(m) of heme a to the positive by 15-20 mV. Na(+) ions that bind to 
      the same site and compete with Ca(2+) do not affect E(m) of heme a and also 
      prevent and reverse the effect of Ca(2+). No effect of Ca(2+) or EGTA is observed 
      on E(m) of heme a with the wild type bacterial oxidases from R.sphaeroides or 
      P.denitrificans that contain tightly-bound calcium at the site. In the D477A 
      mutant CcO from P. denitrificans that binds Ca(2+) reversibly like the 
      mitochondrial CcO, calcium shifts redox titration curve of heme a to the positive 
      by  approximately 35-50 mV that is in good agreement with the results of electrostatic 
      calculations; however, as shown earlier, it does not inhibit CcO activity of the 
      mutant enzyme. Therefore the data do not support the proposal that the inhibitory 
      effect of Ca(2+) on CcO activity may be explained by the Ca(2+)-induced shift of 
      E(m) of heme a. Rather, Ca(2+) retards electron transfer by inhibition of charge 
      dislocation in the exit part of the proton channel H in mammalian CcO, that is 
      absent in the bacterial oxidases.
CI  - Copyright (c) 2018 Elsevier B.V. and Societe Francaise de Biochimie et Biologie 
      Moleculaire (SFBBM). All rights reserved.
FAU - Vygodina, Tatiana V
AU  - Vygodina TV
AD  - A.N.Belozersky Institute of Physico-Chemical Biology, Moscow State University, 
      Moscow, Russia.
FAU - Kaminskaya, Olga P
AU  - Kaminskaya OP
AD  - Institute of Basic Biological Problems, Russian Academy of Sciences, Pushchino, 
      Moscow Region, 142290, Russia.
FAU - Konstantinov, Alexander A
AU  - Konstantinov AA
AD  - A.N.Belozersky Institute of Physico-Chemical Biology, Moscow State University, 
      Moscow, Russia.
FAU - Ptushenko, Vasily V
AU  - Ptushenko VV
AD  - A.N.Belozersky Institute of Physico-Chemical Biology, Moscow State University, 
      Moscow, Russia; N.M.Emanuel Institute of Biochemical Physics, Russian Academy of 
      Sciences, Moscow, Russia. Electronic address: ptush@belozersky.msu.ru.
LA  - eng
PT  - Journal Article
DEP - 20180407
PL  - France
TA  - Biochimie
JT  - Biochimie
JID - 1264604
RN  - 0 (Cations)
RN  - 18535-39-2 (heme a)
RN  - 42VZT0U6YR (Heme)
RN  - EC 1.9.3.1 (Electron Transport Complex IV)
RN  - SY7Q814VUP (Calcium)
SB  - IM
MH  - Animals
MH  - Bacteria/enzymology
MH  - Binding Sites
MH  - Calcium/*chemistry
MH  - Cations/chemistry
MH  - Cattle
MH  - Electron Transport
MH  - Electron Transport Complex IV/*chemistry
MH  - Heme/*analogs & derivatives/chemistry
MH  - Kinetics
MH  - Mitochondria/*chemistry/enzymology
MH  - Oxidation-Reduction
OTO - NOTNLM
OT  - Calcium ions
OT  - Cation binding site (CBS)
OT  - Cytochrome c oxidase
OT  - Heme a
OT  - Potentiometric titrations
EDAT- 2018/04/11 06:00
MHDA- 2018/09/25 06:00
CRDT- 2018/04/11 06:00
PHST- 2017/07/30 00:00 [received]
PHST- 2018/04/04 00:00 [accepted]
PHST- 2018/04/11 06:00 [pubmed]
PHST- 2018/09/25 06:00 [medline]
PHST- 2018/04/11 06:00 [entrez]
AID - S0300-9084(18)30091-9 [pii]
AID - 10.1016/j.biochi.2018.04.005 [doi]
PST - ppublish
SO  - Biochimie. 2018 Jun;149:71-78. doi: 10.1016/j.biochi.2018.04.005. Epub 2018 Apr 
      7.