scholarly journals Cholate Disrupts Regulatory Functions of Cytochrome c Oxidase

Cells ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 1579
Author(s):  
Rabia Ramzan ◽  
Jörg Napiwotzki ◽  
Petra Weber ◽  
Bernhard Kadenbach ◽  
Sebastian Vogt
Keyword(s):  
Cytochrome C ◽  
Cytochrome C Oxidase ◽  
Mitochondrial Respiration ◽  
Sodium Cholate ◽  
Atp Inhibition ◽  
Ros Formation ◽  
Low Levels ◽  
Regulatory Functions ◽  
Relationship Of ◽  
Rate Limiting

Cytochrome c oxidase (CytOx), the oxygen-accepting and rate-limiting enzyme of mitochondrial respiration, binds with 10 molecules of ADP, 7 of which are exchanged by ATP at high ATP/ADP-ratios. These bound ATP and ADP can be exchanged by cholate, which is generally used for the purification of CytOx. Many crystal structures of isolated CytOx were performed with the enzyme isolated from mitochondria using sodium cholate as a detergent. Cholate, however, dimerizes the enzyme isolated in non-ionic detergents and induces a structural change as evident from a spectral change. Consequently, it turns off the “allosteric ATP-inhibition of CytOx”, which is reversibly switched on under relaxed conditions via cAMP-dependent phosphorylation and keeps the membrane potential and ROS formation in mitochondria at low levels. This cholate effect gives an insight into the structural-functional relationship of the enzyme with respect to ATP inhibition and its role in mitochondrial respiration and energy production.

scholarly journals Multiple Mechanisms Regulate Eukaryotic Cytochrome C Oxidase

Cells ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 514
Author(s):  
Rabia Ramzan ◽  
Bernhard Kadenbach ◽  
Sebastian Vogt
Keyword(s):  
Cytochrome C ◽  
Cytochrome C Oxidase ◽  
Mitochondrial Respiration ◽  
Rat Heart ◽  
Isolated Rat Heart ◽  
Atp Inhibition ◽  
Rat Heart Mitochondria ◽  
Rate Limiting ◽  
Regulatory Properties ◽  
Isolated Rat

Cytochrome c oxidase (COX), the rate-limiting enzyme of mitochondrial respiration, is regulated by various mechanisms. Its regulation by ATP (adenosine triphosphate) appears of particular importance, since it evolved early during evolution and is still found in cyanobacteria, but not in other bacteria. Therefore the “allosteric ATP inhibition of COX” is described here in more detail. Most regulatory properties of COX are related to “supernumerary” subunits, which are largely absent in bacterial COX. The “allosteric ATP inhibition of COX” was also recently described in intact isolated rat heart mitochondria.

scholarly journals Metal-binding mechanism of Cox17, a copper chaperone for cytochrome c oxidase

2004 ◽  
Vol 382 (1) ◽  
pp. 307-314 ◽  
Author(s):  
Peep PALUMAA ◽  
Liina KANGUR ◽  
Anastassia VORONOVA ◽  
Rannar SILLARD
Keyword(s):  
Cytochrome C ◽  
Cytochrome C Oxidase ◽  
Metal Binding ◽  
Copper Ions ◽  
Copper Chaperone ◽  
Copper Chaperones ◽  
Rate Limiting Step ◽  
Charge State Distributions ◽  
Rate Limiting ◽  
Partner Proteins

Cox17, a copper chaperone for cytochrome c oxidase, is an essential and highly conserved protein. The structure and mechanism of functioning of Cox17 are unknown, and even its metalbinding stoichiometry is elusive. In the present study, we demonstrate, using electrospray ionization–MS, that porcine Cox17 binds co-operatively four Cu+ ions. Cu4Cox17 is stable at pH values above 3 and fluorescence spectra indicate the presence of a solvent-shielded multinuclear Cu(I) cluster. Combining our results with earlier EXAFS results on yeast CuCox17, we suggest that Cu4Cox17 contains a Cu4S6-type cluster. At supramillimolar concentrations, dithiothreitol extracts metals from Cu4Cox17, and an apparent copper dissociation constant KCu=13 fM was calculated from these results. Charge-state distributions of different Cox17 forms suggest that binding of the first Cu+ ion to Cox17 causes a conformational change from an open to a compact state, which may be the rate-limiting step in the formation of Cu4Cox17. Cox17 binds non-co-operatively two Zn2+ ions, but does not bind Ag+ ions, which highlights its extremely high metal-binding specificity. We further demonstrate that porcine Cox17 can also exist in partly oxidized (two disulphide bridges) and fully oxidized (three disulphide bridges) forms. Partly oxidized Cox17 can bind one Cu+ or Zn2+ ion, whereas fully oxidized Cox17 does not bind metals. The metal-binding properties of Cox17 imply that, in contrast with other copper chaperones, Cox17 is designed for the simultaneous transfer of up to four copper ions to partner proteins. Metals can be released from Cox17 by non-oxidative as well as oxidative mechanisms.

scholarly journals Variasi Genetik Plutella xylostella L. (Lepidoptera: Plutellidae) berdasarkan Gen Cytochrome C Oxidase I

Jurnal MIPA ◽  
2019 ◽  
Vol 8 (1) ◽  
pp. 1
Author(s):  
Claudius F. Kairupan ◽  
Jantje Pelealu ◽  
Juliet M.E. Mamahit
Keyword(s):  
Cytochrome C ◽  
Cytochrome C Oxidase ◽  
Plutella Xylostella ◽  
Coi Gene ◽  
Cytochrome C Oxidase I ◽  
Base Pairs ◽  
Insecticide Application ◽  
Nucleotide Base ◽  
North Sulawesi ◽  
Relationship Of

Daerah Modoinding dan Tomohon di Sulawesi Utara, dikenal sebagai  daerah penghasil sayuran kubis di Indonesia. Sayuran kubis memiliki hama utama yaitu Plutella xylostella. Penyebab serangga ini dapat bertahan hingga saat ini karena adanya sifat resistensi akibat pemberian insektisida yang berlebihan. Penelitian ini dilakukan untuk menganalisis variasi pada gen cytochrome C oxidase IPlutella xylostella yang diperoleh dari dua lokasi yang berbeda, yaitu Modoinding dan Tomohon. Analisis sekuens menunjukkan adanya perbedaan pasang basa nukleotida dari sampel yang berbeda lokasi. Selain itu, variasi juga ditunjukkan pada sampel yang diperoleh dari basis data GenBank dengan adanya perbedaan 1-14 pasang basa nukleotida dengan spesimen pada penelitian ini. Hubungan kekerabatan gen COI P. xylostella keseluruhan sampel tergolong dalam variasi intraspesies dengan nilai jarak genetik berkisar antara 0-0,022 (0-2,20%).Modoinding and Tomohon areas in North Sulawesi, are known as regions in Indonesia that produce a cabbage. The main pest of cabbage, Plutella xylostella. This insect can survive due to its resistance resulted from prolonged insecticide application. This study aims to analyze genetic variation of COI genes in P. xylostella from Modoinding and Tomohon areas. Sequence analysis showed there were differences in nucleotide base pairs between these locations. In addition, variations were also shown in samples obtained from the GenBank database with differences in 1-14 nucleotide base pairs with specimens in this study. The genetic relationship of P. xylostella COI gene in all samples was classified as intraspecific variation with genetic distance values ranging from 0-0,022 (0-2,20%).D aerah Modoinding dan Tomohon di Sulawesi Utara, dikenal sebagaidaerah penghasil sayuran kubis di Indonesia. Sayuran kubis memilikihama utama yaitu Plutella xylostella. Penyebab serangga ini dapatbertahan hingga saat ini karena adanya sifat resistensi akibat pemberianinsektisida yang berlebihan. Penelitian ini dilakukan untuk menganalisisvariasi pada gen cytochrome C oxidase I Plutella xylostella yang diperolehdari dua lokasi yang berbeda, yaitu Modoinding dan Tomohon. Analisissekuens menunjukkan adanya perbedaan pasang basa nukleotida darisampel yang berbeda lokasi. Selain itu, variasi juga ditunjukkan padasampel yang diperoleh dari basis data GenBank dengan adanyaperbedaan 1-14 pasang basa nukleotida dengan spesimen padapenelitian ini. Hubungan kekerabatan gen COI P. xylostella keseluruhansampel tergolong dalam variasi intraspesies dengan nilai jarak genetikberkisar antara 0-0,022 (0-2,20%).

Reversible dimerization of cytochrome c oxidase regulates mitochondrial respiration

Mitochondrion ◽  
2019 ◽  
Vol 49 ◽  
pp. 149-155 ◽  
Author(s):  
Rabia Ramzan ◽  
Annika Rhiel ◽  
Petra Weber ◽  
Bernhard Kadenbach ◽  
Sebastian Vogt
Keyword(s):  
Cytochrome C ◽  
Cytochrome C Oxidase ◽  
Mitochondrial Respiration ◽  
Reversible Dimerization

scholarly journals A Cytochrome c Oxidase Model Catalyzes Oxygen to Water Reduction Under Rate-Limiting Electron Flux

Science ◽  
2007 ◽  
Vol 315 (5818) ◽  
pp. 1565-1568 ◽  
Author(s):  
J. P. Collman ◽  
N. K. Devaraj ◽  
R. A. Decreau ◽  
Y. Yang ◽  
Y.-L. Yan ◽  
...  
Keyword(s):  
Cytochrome C ◽  
Cytochrome C Oxidase ◽  
Electron Flux ◽  
Water Reduction ◽  
Rate Limiting
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