PMID- 32485159
OWN - NLM
STAT- MEDLINE
DCOM- 20201023
LR  - 20201023
IS  - 1879-2650 (Electronic)
IS  - 0005-2728 (Linking)
VI  - 1861
IP  - 9
DP  - 2020 Sep 1
TI  - Modulation of the electron-proton coupling at cytochrome a by the ligation of the 
      oxidized catalytic center in bovine cytochrome c oxidase.
PG  - 148237
LID - S0005-2728(20)30087-6 [pii]
LID - 10.1016/j.bbabio.2020.148237 [doi]
AB  - Cytochrome a was suggested as the key redox center in the proton pumping process 
      of bovine cytochrome c oxidase (CcO). Recent studies showed that both the 
      structure of heme a and its immediate vicinity are sensitive to the ligation and 
      the redox state of the distant catalytic center composed of iron of cytochrome 
      a(3) (Fe(a3)) and copper (Cu(B)). Here, the influence of the ligation at the 
      oxidized Fe(a3)(3+)-Cu(B)(2+) center on the electron-proton coupling at heme a 
      was examined in the wide pH range (6.5-11). The strength of the coupling was 
      evaluated by the determination of pH dependence of the midpoint potential of heme 
      a (E(m)(a)) for the cyanide (the low-spin Fe(a3)(3+)) and the formate-ligated CcO 
      (the high-spin Fe(a3)(3+)). The measurements were performed under experimental 
      conditions when other three redox centers of CcO are oxidized. Two slightly 
      differing linear pH dependencies of E(m)(a) were found for the CN- and the 
      formate-ligated CcO with slopes of -13 mV/pH unit and -23 mV/pH unit, 
      respectively. These linear dependencies indicate only a weak and unspecific 
      electron-proton coupling at cytochrome a in both forms of CcO. The lack of the 
      strong electron-proton coupling at the physiological pH values is also 
      substantiated by the UV-Vis absorption and electron-paramagnetic resonance 
      spectroscopy investigations of the cyanide-ligated oxidized CcO. It is shown that 
      the ligand exchange at Fe(a)(3+) between His-Fe(a)(3+)-His and 
      His-Fe(a)(3+)-OH(-) occurs only at pH above 9.5 with the estimated pK >11.0.
CI  - Copyright (c) 2020 Elsevier B.V. All rights reserved.
FAU - Kopcova, Katarina
AU  - Kopcova K
AD  - Department of Biophysics, Faculty of Science, University of P. J. Safarik, 
      Jesenna 5, 041 54, Kosice, Slovak Republic.
FAU - Mikulova, Ludmila
AU  - Mikulova L
AD  - Center for Interdisciplinary Biosciences, Technology and Innovation Park, 
      University of P. J. Safarik, Jesenna 5, 041 54, Kosice, Slovak Republic.
FAU - Pechova, Ivana
AU  - Pechova I
AD  - Department of Biophysics, Faculty of Science, University of P. J. Safarik, 
      Jesenna 5, 041 54, Kosice, Slovak Republic.
FAU - Sztachova, Tereza
AU  - Sztachova T
AD  - Center for Interdisciplinary Biosciences, Technology and Innovation Park, 
      University of P. J. Safarik, Jesenna 5, 041 54, Kosice, Slovak Republic.
FAU - Cizmar, Erik
AU  - Cizmar E
AD  - Department of Condensed Matter Physics, Faculty of Science, University of P. J. 
      Safarik, Jesenna 5, 041 54, Kosice, Slovak Republic.
FAU - Jancura, Daniel
AU  - Jancura D
AD  - Department of Biophysics, Faculty of Science, University of P. J. Safarik, 
      Jesenna 5, 041 54, Kosice, Slovak Republic; Center for Interdisciplinary 
      Biosciences, Technology and Innovation Park, University of P. J. Safarik, Jesenna 
      5, 041 54, Kosice, Slovak Republic.
FAU - Fabian, Marian
AU  - Fabian M
AD  - Center for Interdisciplinary Biosciences, Technology and Innovation Park, 
      University of P. J. Safarik, Jesenna 5, 041 54, Kosice, Slovak Republic. 
      Electronic address: marian.fabian@upjs.sk.
LA  - eng
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
DEP - 20200530
PL  - Netherlands
TA  - Biochim Biophys Acta Bioenerg
JT  - Biochimica et biophysica acta. Bioenergetics
JID - 101731706
RN  - 0 (Protons)
RN  - 9035-34-1 (Cytochromes a)
RN  - EC 1.9.3.1 (Electron Transport Complex IV)
SB  - IM
MH  - Animals
MH  - Biocatalysis
MH  - *Catalytic Domain
MH  - Cattle
MH  - Cytochromes a/*metabolism
MH  - Electron Transport
MH  - Electron Transport Complex IV/*chemistry/*metabolism
MH  - Oxidation-Reduction
MH  - *Protons
OTO - NOTNLM
OT  - Cytochrome a
OT  - Cytochrome c
OT  - Cytochrome c oxidase
OT  - Electron - paramagnetic resonance spectroscopy
OT  - Redox potential
OT  - pH dependence
COIS- Declaration of competing interest The authors declare that they have no known 
      competing financial interests or personal relationships that could have appeared 
      to influence the work reported in this paper.
EDAT- 2020/06/03 06:00
MHDA- 2020/10/24 06:00
CRDT- 2020/06/03 06:00
PHST- 2020/01/11 00:00 [received]
PHST- 2020/04/29 00:00 [revised]
PHST- 2020/05/25 00:00 [accepted]
PHST- 2020/06/03 06:00 [pubmed]
PHST- 2020/10/24 06:00 [medline]
PHST- 2020/06/03 06:00 [entrez]
AID - S0005-2728(20)30087-6 [pii]
AID - 10.1016/j.bbabio.2020.148237 [doi]
PST - ppublish
SO  - Biochim Biophys Acta Bioenerg. 2020 Sep 1;1861(9):148237. doi: 
      10.1016/j.bbabio.2020.148237. Epub 2020 May 30.