scholarly journals The O2 reduction and proton pumping gate mechanism of bovine heart cytochrome c oxidase

2011 ◽  
Vol 1807 (10) ◽  
pp. 1279-1286 ◽  
Author(s):  
Shinya Yoshikawa ◽  
Kazumasa Muramoto ◽  
Kyoko Shinzawa-Itoh
Keyword(s):  
Cytochrome C ◽  
Cytochrome C Oxidase ◽  
Proton Pumping ◽  
Bovine Heart ◽  
O2 Reduction

scholarly journals The O2 reduction and proton pumping gate mechanisms of bovine heart cytochrome c oxidase

2010 ◽  
Vol 1797 ◽  
pp. 102-103 ◽  
Author(s):  
Kazumasa Muramoto ◽  
Kazuhiro Ohta ◽  
Kyoko Shinzawa-Itoh ◽  
Eiki Yamashita ◽  
Tomitake Tsukihara ◽  
...  
Keyword(s):  
Cytochrome C ◽  
Cytochrome C Oxidase ◽  
Proton Pumping ◽  
Bovine Heart ◽  
O2 Reduction

scholarly journals The proton pumping pathway of bovine heart cytochrome c oxidase

2007 ◽  
Vol 104 (10) ◽  
pp. 4200-4205 ◽  
Author(s):  
K. Shimokata ◽  
Y. Katayama ◽  
H. Murayama ◽  
M. Suematsu ◽  
T. Tsukihara ◽  
...  
Keyword(s):  
Cytochrome C ◽  
Cytochrome C Oxidase ◽  
Proton Pumping ◽  
Bovine Heart

scholarly journals Tracing the Pathways of Waters and Protons in Photosystem II and Cytochrome c Oxidase

Inorganics ◽  
2019 ◽  
Vol 7 (2) ◽  
pp. 14 ◽  
Author(s):  
Divya Kaur ◽  
Xiuhong Cai ◽  
Umesh Khaniya ◽  
Yingying Zhang ◽  
Junjun Mao ◽  
...  
Keyword(s):  
Cytochrome C ◽  
Photosystem Ii ◽  
Cytochrome C Oxidase ◽  
Active Sites ◽  
Proton Pumping ◽  
Oxygen Evolving Complex ◽  
Additional Energy ◽  
Redox Active ◽  
O2 Reduction ◽  
Oxygen Evolving

Photosystem II (PSII) uses water as the terminal electron donor, producing oxygen in the Mn4CaO5 oxygen evolving complex (OEC), while cytochrome c oxidase (CcO) reduces O2 to water in its heme–Cu binuclear center (BNC). Each protein is oriented in the membrane to add to the proton gradient. The OEC, which releases protons, is located near the P-side (positive, at low-pH) of the membrane. In contrast, the BNC is in the middle of CcO, so the protons needed for O2 reduction must be transferred from the N-side (negative, at high pH). In addition, CcO pumps protons from N- to P-side, coupled to the O2 reduction chemistry, to store additional energy. Thus, proton transfers are directly coupled to the OEC and BNC redox chemistry, as well as needed for CcO proton pumping. The simulations that study the changes in proton affinity of the redox active sites and the surrounding protein at different states of the reaction cycle, as well as the changes in hydration that modulate proton transfer paths, are described.

scholarly journals Proton-transfer pathways in the mitochondrial S. cerevisiae cytochrome c oxidase

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Markus L. Björck ◽  
Jóhanna Vilhjálmsdóttir ◽  
Andrew M. Hartley ◽  
Brigitte Meunier ◽  
Linda Näsvik Öjemyr ◽  
...  
Keyword(s):  
Cytochrome C ◽  
Proton Transfer ◽  
Cytochrome C Oxidase ◽  
Proton Pumping ◽  
Heart Mitochondria ◽  
Negative Side ◽  
Bovine Heart ◽  
Proton Uptake ◽  
Mammalian Counterpart ◽  
Kinetics Of

AbstractIn cytochrome c oxidase (CytcO) reduction of O2 to water is linked to uptake of eight protons from the negative side of the membrane: four are substrate protons used to form water and four are pumped across the membrane. In bacterial oxidases, the substrate protons are taken up through the K and the D proton pathways, while the pumped protons are transferred through the D pathway. On the basis of studies with CytcO isolated from bovine heart mitochondria, it was suggested that in mitochondrial CytcOs the pumped protons are transferred though a third proton pathway, the H pathway, rather than through the D pathway. Here, we studied these reactions in S. cerevisiae CytcO, which serves as a model of the mammalian counterpart. We analyzed the effect of mutations in the D (Asn99Asp and Ile67Asn) and H pathways (Ser382Ala and Ser458Ala) and investigated the kinetics of electron and proton transfer during the reaction of the reduced CytcO with O2. No effects were observed with the H pathway variants while in the D pathway variants the functional effects were similar to those observed with the R. sphaeroides CytcO. The data indicate that the S. cerevisiae CytcO uses the D pathway for proton uptake and presumably also for proton pumping.

Reaction mechanism and phospholipid structures of bovine heart cytochrome c oxidase

2005 ◽  
Vol 33 (5) ◽  
pp. 934-937 ◽  
Author(s):  
S. Yoshikawa
Keyword(s):  
Hydrogen Bond ◽  
Cytochrome C ◽  
Cytochrome C Oxidase ◽  
Hydrogen Bond Network ◽  
X Ray ◽  
Bovine Heart ◽  
O2 Reduction ◽  
Bond Network ◽  
Electron Reduction ◽  
Enzyme Functions

Bovine heart cytochrome c oxidase is a large multi-component membrane protein containing several phospholipids. X-ray structures of this enzyme at high resolution, determined recently, show a trigonal planar structure of CuB site in the O2 reduction site, which could contribute critically to the four-electron reduction of O2 bound at haem a3, and a hydrogen bond network, through which the proton pump is driven by haem a. The possible roles of phospholipids in the enzyme functions are discussed.

Stepwise Binding of Two Azide Ions to the O2-reduction Site of Bovine Heart Cytochrome c Oxidase Shown by Resonance Raman Analyses

2015 ◽  
Vol 44 (8) ◽  
pp. 1142-1144 ◽  
Author(s):  
Masahide Hikita ◽  
Akima Yamamoto ◽  
Kyoko Shinzawa-Itoh ◽  
Takashi Ogura ◽  
Shinya Yoshikawa
Keyword(s):  
Cytochrome C ◽  
Cytochrome C Oxidase ◽  
Resonance Raman ◽  
Bovine Heart ◽  
O2 Reduction
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