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Vogt S, Ramzan R, Cybulski P, Rhiel A, Weber P, Ruppert V, Irqsusi M, Rohrbach S, Niemann B, Mirow N, Rastan AJ. The ratio of cytochrome c oxidase subunit 4 isoform 4I1 and 4I2 mRNA is changed in permanent atrial fibrillation. ESC Heart Fail 2024; 11:1525-1539. [PMID: 38149324 PMCID: PMC11098639 DOI: 10.1002/ehf2.14607] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2022] [Revised: 08/11/2023] [Accepted: 11/16/2023] [Indexed: 12/28/2023] Open
Abstract
AIMS The conditions of hypoxia are suggested to induce permanent atrial fibrillation (AF). The regulation of COX4I2 and COX4I1 depends on oxygen availability in tissues. A role of COX4I2 in the myocardium of AF patients is supposed for pathogenesis of AF and subsequent alterations in the electron transfer chain (ETC) under hypoxia. METHODS AND RESULTS In vitro, influence of hypoxia on HeLa 53 cells was studied and elevated parts of COX 4I2 were confirmed. Myocardial biopsies were taken ex vivo from the patients' Right Atria with SR (n = 31) and AF (n = 11), respectively. RT- PCR for mRNA expresson, mitochondrial respiration by polarography and the protein content of cytochrome c oxidase (CytOx) subunit 4I1 and CytOx subunit 4I2 by ELISA were studied. Clinical data were correlated to the findings of gene expressions in parallel. Patients with permanent AF had a change in isoform 4I2/4I1 expression along with a decrease of isoform COX 4I1 expression. The 4I2/4I1 ratio of mRNA expression was increased from 0.630 to 1.058 in comparison. However, the protein content of CytOx subunit 4 was much lower in the AF group, whereas the respiration/units enzyme activity in both groups remained the same. CONCLUSIONS This study describes a possible molecular correlate for the development of AF. Due to the known functional significance of COX 4I2, mitochondrial dysfunction can be assumed as a part of the pathogenesis of AF.
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Affiliation(s)
- Sebastian Vogt
- Cardiovascular Research LabPhilipps‐University MarburgMarburgGermany
- Department of Cardiac and Vascular SurgeryUniversity Hospital of Giessen and MarburgMarburgGermany
| | - Rabia Ramzan
- Cardiovascular Research LabPhilipps‐University MarburgMarburgGermany
- Department of Cardiac and Vascular SurgeryUniversity Hospital of Giessen and MarburgMarburgGermany
| | - Pia Cybulski
- Cardiovascular Research LabPhilipps‐University MarburgMarburgGermany
| | - Annika Rhiel
- Cardiovascular Research LabPhilipps‐University MarburgMarburgGermany
| | - Petra Weber
- Cardiovascular Research LabPhilipps‐University MarburgMarburgGermany
| | - Volker Ruppert
- Department of CardiologyUniversity Hospital of Giessen and MarburgMarburgGermany
| | - Marc Irqsusi
- Department of Cardiac and Vascular SurgeryUniversity Hospital of Giessen and MarburgMarburgGermany
| | - Susanne Rohrbach
- Institute of PhysiologyJustus Liebig University GiessenGiessenGermany
| | - Bernd Niemann
- Department of Cardiac and Vascular SurgeryUniversity Hospital of Giessen and MarburgGiessenGermany
| | - Nikolas Mirow
- Department of Cardiac and Vascular SurgeryUniversity Hospital of Giessen and MarburgMarburgGermany
| | - Ardawan J. Rastan
- Department of Cardiac and Vascular SurgeryUniversity Hospital of Giessen and MarburgMarburgGermany
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Chertkova RV, Oleynikov IP, Pakhomov AA, Sudakov RV, Orlov VN, Semenova MA, Arutyunyan AM, Ptushenko VV, Kirpichnikov MP, Dolgikh DA, Vygodina TV. Mutant Cytochrome C as a Potential Detector of Superoxide Generation: Effect of Mutations on the Function and Properties. Cells 2023; 12:2316. [PMID: 37759538 PMCID: PMC10528150 DOI: 10.3390/cells12182316] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2023] [Revised: 09/08/2023] [Accepted: 09/15/2023] [Indexed: 09/29/2023] Open
Abstract
Cytochrome c (CytC) is a single-electron carrier between complex bc1 and cytochrome c-oxidase (CcO) in the electron transport chain (ETC). It is also known as a good radical scavenger but its participation in electron flow through the ETC makes it impossible to use CytC as a radical sensor. To solve this problem, a series of mutants were constructed with substitutions of Lys residues in the universal binding site (UBS) which interact electrostatically with negatively charged Asp and Glu residues at the binding sites of CytC partners, bc1 complex and CcO. The aim of this study was to select a mutant that had lost its function as an electron carrier in the ETC, retaining the structure and ability to quench radicals. It was shown that a mutant CytC with substitutions of five (8Mut) and four (5Mut) Lys residues in the UBS was almost inactive toward CcO. However, all mutant proteins kept their antioxidant activity sufficiently with respect to the superoxide radical. Mutations shifted the dipole moment of the CytC molecule due to seriously changed electrostatics on the surface of the protein. In addition, a decrease in the redox potential of the protein as revealed by the redox titrations of 8Mut was detected. Nevertheless, the CD spectrum and dynamic light scattering suggested no significant changes in the secondary structure or aggregation of the molecules of CytC 8Mut. Thus, a variant 8Mut with multiple mutations in the UBS which lost its ability to electron transfer and saved most of its physico-chemical properties can be effectively used as a detector of superoxide generation both in mitochondria and in other systems.
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Affiliation(s)
- Rita V. Chertkova
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, 117997 Moscow, Russia; (A.A.P.); (M.A.S.); (M.P.K.); (D.A.D.)
| | - Ilya P. Oleynikov
- A.N. Belozersky Institute of Physico-Chemical Biology, M.V. Lomonosov Moscow State University, Leninskie gory 1, Bld. 40, 119992 Moscow, Russia; (I.P.O.); (R.V.S.); (V.N.O.); (A.M.A.); (T.V.V.)
| | - Alexey A. Pakhomov
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, 117997 Moscow, Russia; (A.A.P.); (M.A.S.); (M.P.K.); (D.A.D.)
| | - Roman V. Sudakov
- A.N. Belozersky Institute of Physico-Chemical Biology, M.V. Lomonosov Moscow State University, Leninskie gory 1, Bld. 40, 119992 Moscow, Russia; (I.P.O.); (R.V.S.); (V.N.O.); (A.M.A.); (T.V.V.)
| | - Victor N. Orlov
- A.N. Belozersky Institute of Physico-Chemical Biology, M.V. Lomonosov Moscow State University, Leninskie gory 1, Bld. 40, 119992 Moscow, Russia; (I.P.O.); (R.V.S.); (V.N.O.); (A.M.A.); (T.V.V.)
| | - Marina A. Semenova
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, 117997 Moscow, Russia; (A.A.P.); (M.A.S.); (M.P.K.); (D.A.D.)
| | - Alexander M. Arutyunyan
- A.N. Belozersky Institute of Physico-Chemical Biology, M.V. Lomonosov Moscow State University, Leninskie gory 1, Bld. 40, 119992 Moscow, Russia; (I.P.O.); (R.V.S.); (V.N.O.); (A.M.A.); (T.V.V.)
| | - Vasily V. Ptushenko
- A.N. Belozersky Institute of Physico-Chemical Biology, M.V. Lomonosov Moscow State University, Leninskie gory 1, Bld. 40, 119992 Moscow, Russia; (I.P.O.); (R.V.S.); (V.N.O.); (A.M.A.); (T.V.V.)
- N.M. Emanuel Institute of Biochemical Physics of the Russian Academy of Sciences, 119334 Moscow, Russia
| | - Mikhail P. Kirpichnikov
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, 117997 Moscow, Russia; (A.A.P.); (M.A.S.); (M.P.K.); (D.A.D.)
- Biology Department, M.V. Lomonosov Moscow State University, 119899 Moscow, Russia
| | - Dmitry A. Dolgikh
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, 117997 Moscow, Russia; (A.A.P.); (M.A.S.); (M.P.K.); (D.A.D.)
- Biology Department, M.V. Lomonosov Moscow State University, 119899 Moscow, Russia
| | - Tatiana V. Vygodina
- A.N. Belozersky Institute of Physico-Chemical Biology, M.V. Lomonosov Moscow State University, Leninskie gory 1, Bld. 40, 119992 Moscow, Russia; (I.P.O.); (R.V.S.); (V.N.O.); (A.M.A.); (T.V.V.)
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Muramoto K, Shinzawa-Itoh K. Calcium-bound structure of bovine cytochrome c oxidase. BIOCHIMICA ET BIOPHYSICA ACTA. BIOENERGETICS 2023; 1864:148956. [PMID: 36708913 DOI: 10.1016/j.bbabio.2023.148956] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/24/2022] [Revised: 01/11/2023] [Accepted: 01/20/2023] [Indexed: 01/26/2023]
Abstract
The crystal structure of bovine cytochrome c oxidase (CcO) shows a sodium ion (Na+) bound to the surface of subunit I. Changes in the absorption spectrum of heme a caused by calcium ions (Ca2+) are detected as small red shifts, and inhibition of enzymatic activity under low turnover conditions is observed by addition of Ca2+ in a competitive manner with Na+. In this study, we determined the crystal structure of Ca2+-bound bovine CcO in the oxidized and reduced states at 1.7 Å resolution. Although Ca2+ and Na+ bound to the same site of oxidized and reduced CcO, they led to different coordination geometries. Replacement of Na+ with Ca2+ caused a small structural change in the loop segments near the heme a propionate and formyl groups, resulting in spectral changes in heme a. Redox-coupled structural changes observed in the Ca2+-bound form were the same as those previously observed in the Na+-bound form, suggesting that binding of Ca2+ does not severely affect enzymatic function, which depends on these structural changes. The relation between the Ca2+ binding and the inhibitory effect during slow turnover, as well as the possible role of bound Ca2+ are discussed.
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Affiliation(s)
- Kazumasa Muramoto
- Graduate School of Science, University of Hyogo, 3-2-1 Kouto, Kamigori, Ako, Hyogo 678-1297, Japan.
| | - Kyoko Shinzawa-Itoh
- Graduate School of Science, University of Hyogo, 3-2-1 Kouto, Kamigori, Ako, Hyogo 678-1297, Japan.
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Oleynikov IP, Azarkina NV, Vygodina TV, Konstantinov AA. Interaction of Cytochrome C Oxidase with Steroid Hormones. Cells 2020; 9:cells9102211. [PMID: 33003582 PMCID: PMC7601700 DOI: 10.3390/cells9102211] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2020] [Revised: 09/20/2020] [Accepted: 09/23/2020] [Indexed: 12/16/2022] Open
Abstract
Estradiol, testosterone and other steroid hormones inhibit cytochrome c oxidase (CcO) purified from bovine heart. The inhibition is strongly dependent on concentration of dodecyl-maltoside (DM) in the assay. The plots of Ki vs [DM] are linear for both estradiol and testosterone which may indicate an 1:1 stoichiometry competition between the hormones and the detergent. Binding of estradiol, but not of testosterone, brings about spectral shift of the oxidized CcO consistent with an effect on heme a33+. We presume that the hormones bind to CcO at the bile acid binding site described by Ferguson-Miller and collaborators. Estradiol is shown to inhibit intraprotein electron transfer between hemes a and a3. Notably, neither estradiol nor testosterone suppresses the peroxidase activity of CcO. Such a specific mode of action indicates that inhibition of CcO activity by the hormones is associated with impairing proton transfer via the K-proton channel.
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