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Guerin MN, Ellis TS, Ware MJ, Manning A, Coley AA, Amini A, Igboanugo AG, Rothrock AP, Chung G, Gunsalus KC, Bracht JR. Evolution of a biological thermocouple by adaptation of cytochrome c oxidase in a subterrestrial metazoan, Halicephalobus mephisto. Commun Biol 2024; 7:1214. [PMID: 39342021 DOI: 10.1038/s42003-024-06886-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2024] [Accepted: 09/12/2024] [Indexed: 10/01/2024] Open
Abstract
In this study, we report a biological temperature-sensing electrical regulator in the cytochrome c oxidase of the Devil Worm, Halicephalobus mephisto. This extremophile metazoan was isolated 1.3 km underground in a South African goldmine, where it adapted to heat and potentially to hypoxia, making its mitochondrial sequence a likely target of adaptational change. We obtained the complete mitochondrial genome sequence of this organism and show through dN/dS analysis evidence of positive selection in H. mephisto cytochrome c oxidase subunits. Seventeen of these positively selected amino acid substitutions were located in proximity to the H- and K-pathway proton channels of the complex. Surprisingly, the H. mephisto cytochrome c oxidase completely shuts down at low temperatures (20 °C), leading to a 4.8-fold reduction in the transmembrane proton gradient (ΔΨm) compared to optimal temperature (37 °C). Direct measurement of oxygen consumption found a corresponding 4.6-fold drop at 20 °C compared to 37 °C. Correspondingly, the lifecycle of H. mephisto takes four times longer at low temperature than at higher. This elegant evolutionary adaptation creates a finely-tuned mitochondrial temperature sensor, allowing this ectothermic organism to maximize its reproductive success across varying environmental temperatures.
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Affiliation(s)
- Megan N Guerin
- Biology Department, American University, 4400 Massachusetts Avenue, NW, Washington, DC, 20016, USA
| | - TreVaughn S Ellis
- Biology Department, American University, 4400 Massachusetts Avenue, NW, Washington, DC, 20016, USA
| | - Mark J Ware
- Biology Department, American University, 4400 Massachusetts Avenue, NW, Washington, DC, 20016, USA
| | - Alexandra Manning
- Biology Department, American University, 4400 Massachusetts Avenue, NW, Washington, DC, 20016, USA
| | - Ariana A Coley
- Biology Department, American University, 4400 Massachusetts Avenue, NW, Washington, DC, 20016, USA
| | - Ali Amini
- Mathematics and Statistics Department, American University, 4400 Massachusetts Avenue, NW, Washington, DC, 20016, USA
| | - Adaeze G Igboanugo
- Biology Department, American University, 4400 Massachusetts Avenue, NW, Washington, DC, 20016, USA
| | - Amaya P Rothrock
- Biology Department, American University, 4400 Massachusetts Avenue, NW, Washington, DC, 20016, USA
| | - George Chung
- Center for Genomics and Systems Biology and Department of Biology, New York University, New York, NY, 10003, USA
| | - Kristin C Gunsalus
- Center for Genomics and Systems Biology and Department of Biology, New York University, New York, NY, 10003, USA
| | - John R Bracht
- Biology Department, American University, 4400 Massachusetts Avenue, NW, Washington, DC, 20016, USA.
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2
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Guerin MN, Ellis T, Ware MJ, Manning A, Coley A, Amini A, Chung G, Gunsalus KC, Bracht JR. Evolution of a biological thermocouple by adaptation of cytochrome c oxidase in a subterrestrial metazoan. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.12.05.570156. [PMID: 38106155 PMCID: PMC10723328 DOI: 10.1101/2023.12.05.570156] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/19/2023]
Abstract
In this study we report a naturally evolved temperature-sensing electrical regulator in the cytochrome c oxidase of the Devil Worm, Halicephalobus mephisto. This extremophile metazoan was isolated 1.3 km underground in a South African goldmine, where it adapted to heat and potentially to hypoxia, making its mitochondrial sequence a likely target of adaptational change. We obtained the full mitochondrial genome sequence of this organism, and show through dN/dS analysis statistically robust evidence of positive selection in H. mephisto cytochrome c oxidase subunits. Seventeen of these positively-selected amino acid substitutions were localized in proximity to the H- and K-pathway proton channels of the complex. Surprisingly, the H. mephisto cytochrome c oxidase proton pump completely shuts down at low temperatures (20°C) leading to approximately a 4.8-fold reduction in the transmembrane proton gradient voltage (ΔΨm) compared to optimal temperature (37°C). Direct measurement of oxygen consumption found a corresponding 4.7-fold drop at 20°C compared to 37°C. Correspondingly, the lifecycle of H. mephisto takes four-fold longer at the low temperature compared to higher. This elegant evolutionary adaptation creates a finely-tuned mitochondrial temperature sensor, allowing this ectothermic organism to maximize its reproductive success in varying environmental temperatures. Our study shows that evolutionary innovation may remodel core metabolism to make it more accurately map onto environmental variation.
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Affiliation(s)
- Megan N Guerin
- American University Biology Department, 4400 Massachusetts Avenue, NW, Washington, DC, United States, 20016
| | - TreVaughn Ellis
- American University Biology Department, 4400 Massachusetts Avenue, NW, Washington, DC, United States, 20016
| | - Mark J Ware
- American University Biology Department, 4400 Massachusetts Avenue, NW, Washington, DC, United States, 20016
| | - Alexandra Manning
- American University Biology Department, 4400 Massachusetts Avenue, NW, Washington, DC, United States, 20016
| | - Ariana Coley
- American University Biology Department, 4400 Massachusetts Avenue, NW, Washington, DC, United States, 20016
| | - Ali Amini
- American University Mathematics and Statistics Department, 4400 Massachusetts Avenue, NW, Washington, DC, United States, 20016
| | - George Chung
- New York University, Center for Genomics and Systems Biology, New York, NY 10003
| | - Kristin C Gunsalus
- New York University, Center for Genomics and Systems Biology, New York, NY 10003
| | - John R Bracht
- American University Biology Department, 4400 Massachusetts Avenue, NW, Washington, DC, United States, 20016
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Heras-Molina A, Núñez Y, Benítez R, Pesántez-Pacheco JL, García-Contreras C, Vázquez-Gómez M, Astiz S, Isabel B, González-Bulnes A, Óvilo C. Hypothalamic transcriptome analysis reveals male-specific differences in molecular pathways related to oxidative phosphorylation between Iberian pig genotypes. PLoS One 2022; 17:e0272775. [PMID: 35972914 PMCID: PMC9380940 DOI: 10.1371/journal.pone.0272775] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2022] [Accepted: 07/27/2022] [Indexed: 11/29/2022] Open
Abstract
The hypothalamus is implicated in controlling feeding and adiposity, besides many other physiological functions, and thus can be of great importance in explaining productive differences between lean and fatty pig breeds. The present study aimed to evaluate the hypothalamic transcriptome of pure Iberian (IBxIB) and Large White x Iberian crossbreds (IBxLW) at 60 days-old, produced in a single maternal environment. Results showed the implication of gender and genotype in the hypothalamic transcriptome, with 51 differentially expressed genes (DEGs) between genotypes and 10 DEGs between genders. Fourteen genotype by sex interactions were found, due to a higher genotype effect on transcriptome found in males. In fact, just 31 DEGs were identified when using only females but 158 using only males. A higher expression of genes related to mitochondrial activity in IBxIB male animals (ND3, ND4, ND5, UQCRC2 and ATP6) was found, which was related to a higher oxidative phosphorylation and greater reactive oxygen species and nitric oxide production. IBxLW male animals showed higher expression of SIRT3 regulator, also related to mitochondrial function. When females were analysed, such differences were not found, since only some differences in genes related to the tricarboxylic acid cycle. Thus, the results indicate a significant effect and interaction of the breed and the sex on the hypothalamic transcriptome at this early age.
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Affiliation(s)
- Ana Heras-Molina
- Department of Animal Breeding, INIA-CSIC, Madrid, Spain
- Department of Animal Production, Veterinary Faculty, UCM, Madrid, Spain
- * E-mail:
| | - Yolanda Núñez
- Department of Animal Breeding, INIA-CSIC, Madrid, Spain
| | - Rita Benítez
- Department of Animal Breeding, INIA-CSIC, Madrid, Spain
| | - José Luis Pesántez-Pacheco
- Department of Animal Reproduction, INIA-CSIC, Madrid, Spain
- School of Veterinary Medicine and Zootechnics, Faculty of Agricultural Sciences, UC, Cuenca, Ecuador
| | | | - Marta Vázquez-Gómez
- Department of Animal Production, Veterinary Faculty, UCM, Madrid, Spain
- Nutrition and Obesities: Systemic Approaches Research Unit (NutriOmics), INSERM, Sorbonne Université, Paris, France
| | - Susana Astiz
- Department of Animal Reproduction, INIA-CSIC, Madrid, Spain
| | - Beatriz Isabel
- Department of Animal Production, Veterinary Faculty, UCM, Madrid, Spain
| | - Antonio González-Bulnes
- Department of Animal Reproduction, INIA-CSIC, Madrid, Spain
- Department of Animal Production, Veterinary Faculty, UCH-CEU, Valencia, Spain
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Xue Y, Yin Y, Trabi EB, Xie F, Lin L, Mao S. Transcriptome analysis reveals the effect of high-grain pelleted and non-pelleted diets on ruminal epithelium of Hu-lamb. Animal 2021; 15:100278. [PMID: 34126388 DOI: 10.1016/j.animal.2021.100278] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2021] [Revised: 05/08/2021] [Accepted: 05/11/2021] [Indexed: 10/21/2022] Open
Abstract
High-grain non-pelleted (HG) and high-grain pelleted (HP) diets are becoming prevalent for ruminant feeding in intensive farms. However, rare information is about their effect on sheep and the comparison between these two kinds of diets. The current study investigated how HG and HP diets affected the transcriptome profiles of rumen epithelium in Hu-lamb. Fifteen male Hu-lambs were assigned randomly to three groups (n = 5 for each group). Lambs in the control (CON), HG, and HP groups were fed with low-grain non-pelleted diet (30% grain), HG diet (70% grain), and HP diet (70% grain), respectively, for 42 days. All these lambs were slaughtered to collect ruminal epithelium samples for transcriptome analysis. Results showed both HG and HP diets obviously changed the transcriptome profiles, and 192, 319, and three differentially expressed genes (DEGs) were identified for CON_HG, CON_HP, and HG_HP comparisons, respectively. Clusters of orthologous group functional classification of CON_HG and CON_HP DEG datasets both showed the enrichments of DEGs in pathways involved in protein biogenesis and modification as well as energy production and conversion. Kyoto encyclopedia of genes and genomes pathway analysis of CON_HG and CON_HP DEG datasets both displayed the enrichments of DEGs in ribosome and oxidative phosphorylation. Almost all these DEGs involved in translation and ribosomal structure and biogenesis as well as oxidative phosphorylation were downregulated in the HG and HP groups compared to the CON group. Furthermore, CON_HP comparison demonstrated more DEGs related to these two pathways than CON_HG comparison. In conclusion, both HG and HP diets inhibited energy production and conversion as well as protein synthesis and modification in ruminal epithelium. HP diet showed lower growth benefits, induced severer rumen acidosis, and more seriously inhibited energy production and protein synthesis as compared to HG diet.
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Affiliation(s)
- Y Xue
- Centre for Ruminant Nutrition and Feed Technology Research, College of Animal Science and Technology, Nanjing Agricultural University, Nanjing 210095, China; Jilin Inter-Regional Cooperation Centre for the Scientific and Technological Innovation of Ruminant Precision Nutrition and Smart and Ecological Farming, 132109 Jilin, China
| | - Y Yin
- Huzhou Academy of Agricultural Sciences, Huzhou 313000, China
| | - E B Trabi
- Centre for Ruminant Nutrition and Feed Technology Research, College of Animal Science and Technology, Nanjing Agricultural University, Nanjing 210095, China; Jilin Inter-Regional Cooperation Centre for the Scientific and Technological Innovation of Ruminant Precision Nutrition and Smart and Ecological Farming, 132109 Jilin, China
| | - F Xie
- Centre for Ruminant Nutrition and Feed Technology Research, College of Animal Science and Technology, Nanjing Agricultural University, Nanjing 210095, China; Jilin Inter-Regional Cooperation Centre for the Scientific and Technological Innovation of Ruminant Precision Nutrition and Smart and Ecological Farming, 132109 Jilin, China
| | - L Lin
- Centre for Ruminant Nutrition and Feed Technology Research, College of Animal Science and Technology, Nanjing Agricultural University, Nanjing 210095, China; Jilin Inter-Regional Cooperation Centre for the Scientific and Technological Innovation of Ruminant Precision Nutrition and Smart and Ecological Farming, 132109 Jilin, China
| | - S Mao
- Centre for Ruminant Nutrition and Feed Technology Research, College of Animal Science and Technology, Nanjing Agricultural University, Nanjing 210095, China; Jilin Inter-Regional Cooperation Centre for the Scientific and Technological Innovation of Ruminant Precision Nutrition and Smart and Ecological Farming, 132109 Jilin, China.
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5
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Awasthi P, Singh A, Khatun S, Gupta AN, Das S. Fibril growth captured by electrical properties of amyloid-β and human islet amyloid polypeptide. Phys Rev E 2021; 101:062413. [PMID: 32688470 DOI: 10.1103/physreve.101.062413] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2020] [Accepted: 05/22/2020] [Indexed: 11/07/2022]
Abstract
The aggregation of amyloid-β (Aβ) and human islet amyloid polypeptide (hIAPP) proteins have attracted considerable attention because of their involvement in protein misfolding diseases. These proteins have mostly been investigated using atomic force microscopy, transmission electron microscopy, and fluorescence microscopy to study the directional growth of fibrils both perpendicular to and along the fibril axis. Here, we demonstrate the real-time monitoring of the directional growth of fibrils in terms of activation energy of proton transfer using an impedance spectroscopy technique. The activation energy is used to quantify the sensitivity of proton conduction to the different stages of protein aggregation. The decrement (increment) in activation energy is related to the fibril growth along (perpendicular to) the fibril axis in intrinsic protein aggregation. The entire aggregation process shows different phases of the directional growth for Aβ and hIAPP, indicating different pathways for their aggregation. The activation energy for hIAPP is found to be smaller than the activation energy of Aβ during the aggregation process. The oscillatory behavior of the activation energy of hIAPP reflects a rapid change in the directional growth of the protofilaments of hIAPP. The results indicate higher aggregation propensity of Aβ than hIAPP. In the presence of resveratrol, hIAPP exhibits slower aggregation compared to Aβ. Methods of this study may in general be used to reveal the modulated aggregation pathway of proteins in the presence of different ligands.
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Affiliation(s)
- Prasoon Awasthi
- BioMEMS Laboratory, School of Medical Science and Technology, Indian Institute of Technology Kharagpur, 721302, India
| | - Anurag Singh
- Biophysics and Soft Matter Laboratory, Department of Physics, Indian Institute of Technology Kharagpur, 721302, India
| | - Suparna Khatun
- Biophysics and Soft Matter Laboratory, Department of Physics, Indian Institute of Technology Kharagpur, 721302, India
| | - Amar Nath Gupta
- Biophysics and Soft Matter Laboratory, Department of Physics, Indian Institute of Technology Kharagpur, 721302, India
| | - Soumen Das
- BioMEMS Laboratory, School of Medical Science and Technology, Indian Institute of Technology Kharagpur, 721302, India
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6
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Ramzan R, Kadenbach B, Vogt S. Multiple Mechanisms Regulate Eukaryotic Cytochrome C Oxidase. Cells 2021; 10:cells10030514. [PMID: 33671025 PMCID: PMC7997345 DOI: 10.3390/cells10030514] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2021] [Revised: 02/22/2021] [Accepted: 02/22/2021] [Indexed: 02/07/2023] Open
Abstract
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.
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Affiliation(s)
- Rabia Ramzan
- Cardiovascular Research Laboratory, Biochemical-Pharmacological Center, Philipps-University Marburg, Karl-von-Frisch-Strasse 1, D-35043 Marburg, Germany;
| | - Bernhard Kadenbach
- Fachbereich Chemie, Philipps-University, D-35032 Marburg, Germany
- Correspondence:
| | - Sebastian Vogt
- Department of Heart Surgery, Campus Marburg, University Hospital of Giessen and Marburg, D-35043 Marburg, Germany;
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7
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Thiel NA, Sachett A, Schneider SE, Garbinato C, Decui L, Eichwald T, Conterato GMM, Latini A, Piato A, Siebel AM. Exposure to the herbicide 2,4-dichlorophenoxyacetic acid impairs mitochondrial function, oxidative status, and behavior in adult zebrafish. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2020; 27:45874-45882. [PMID: 32803608 DOI: 10.1007/s11356-020-10497-6] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/25/2020] [Accepted: 08/12/2020] [Indexed: 06/11/2023]
Abstract
2,4-Dichlorophenoxyacetic acid (2,4-D) is one of the most commonly used herbicides worldwide. While the effects of 2,4-D in target organisms are well known, its consequences in nontarget organisms are not fully explained. Therefore, the purpose of this study was to investigate the effects of the herbicide on mitochondrial energy metabolism, oxidative status, and exploratory behavior in adult zebrafish. Animal exposure to 2,4-D increased cytochrome c oxidase and catalase activities and reduced SOD/CAT ratio, moreover, increased the total distance traveled and the number of crossings. Finally, animals exposed to 2,4-D spent more time in the upper zone of the tank and traveled a long distance in the upper zone. Overall, our results indicate the 2,4-D can provoke disabling effects in nontarget organisms. The obtained data showed that exposure to 2,4-D at environmentally relevant concentrations alters mitochondrial metabolism and antioxidant status and disturbs the zebrafish innate behavior.
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Affiliation(s)
- Nathana Andressa Thiel
- Laboratório de Genética e Ecotoxicologia Molecular, Programa de Pós-Graduação em Ciências Ambientais, Universidade Comunitária da Região de Chapecó, Servidão Anjo da Guarda, 295-D, Efapi, Chapecó, SC, 89809-900, Brazil
| | - Adrieli Sachett
- Laboratório de Psicofarmacologia e Comportamento, Programa de Pós-Graduação em Neurociências, Universidade Federal do Rio Grande do Sul, Sarmento Leite, 500, Centro Histórico, Porto Alegre, RS, 90050-170, Brazil
| | - Sabrina Ester Schneider
- Laboratório de Genética e Ecotoxicologia Molecular, Curso de Ciências Biológicas, Universidade Comunitária da Região de Chapecó, Servidão Anjo da Guarda, 295-D, Efapi, Chapecó, SC, 89809-900, Brazil
| | - Cristiane Garbinato
- Laboratório de Genética e Ecotoxicologia Molecular, Programa de Pós-Graduação em Ciências Ambientais, Universidade Comunitária da Região de Chapecó, Servidão Anjo da Guarda, 295-D, Efapi, Chapecó, SC, 89809-900, Brazil
| | - Laura Decui
- Laboratório de Genética e Ecotoxicologia Molecular, Curso de Ciências Biológicas, Universidade Comunitária da Região de Chapecó, Servidão Anjo da Guarda, 295-D, Efapi, Chapecó, SC, 89809-900, Brazil
| | - Tuany Eichwald
- Laboratório de Bioenergética e Estresse Oxidativo, Departamento de Bioquímica, Centro de Ciências Biológicas, Universidade Federal de Santa Catarina, Campus Universitário Trindade, Florianópolis, SC, 88040-900, Brazil
| | - Greicy M M Conterato
- Laboratório de Fisiologia da Reprodução Animal, Departamento de Agricultura, Biodiversidade e Floresta, Universidade Federal de Santa Catarina, Campus de Curitibanos, Rodovia Ulysses Gaboardi, Curitibanos, SC, 89520-000, Brazil
| | - Alexandra Latini
- Laboratório de Bioenergética e Estresse Oxidativo, Departamento de Bioquímica, Centro de Ciências Biológicas, Universidade Federal de Santa Catarina, Campus Universitário Trindade, Florianópolis, SC, 88040-900, Brazil
| | - Angelo Piato
- Laboratório de Psicofarmacologia e Comportamento, Programa de Pós-Graduação em Neurociências, Universidade Federal do Rio Grande do Sul, Sarmento Leite, 500, Centro Histórico, Porto Alegre, RS, 90050-170, Brazil
| | - Anna Maria Siebel
- Laboratório de Genética e Ecotoxicologia Molecular, Programa de Pós-Graduação em Ciências Ambientais, Universidade Comunitária da Região de Chapecó, Servidão Anjo da Guarda, 295-D, Efapi, Chapecó, SC, 89809-900, Brazil.
- Laboratório de Genética e Ecotoxicologia Molecular, Curso de Ciências Biológicas, Universidade Comunitária da Região de Chapecó, Servidão Anjo da Guarda, 295-D, Efapi, Chapecó, SC, 89809-900, Brazil.
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8
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Kadenbach B. Complex IV - The regulatory center of mitochondrial oxidative phosphorylation. Mitochondrion 2020; 58:296-302. [PMID: 33069909 DOI: 10.1016/j.mito.2020.10.004] [Citation(s) in RCA: 81] [Impact Index Per Article: 20.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2020] [Revised: 09/01/2020] [Accepted: 10/12/2020] [Indexed: 12/19/2022]
Abstract
ATP, the universal energy currency in all living cells, is mainly synthesized in mitochondria by oxidative phosphorylation (OXPHOS). The final and rate limiting step of the respiratory chain is cytochrome c oxidase (COX) which represents the regulatory center of OXPHOS. COX is regulated through binding of various effectors to its "supernumerary" subunits, by reversible phosphorylation, and by expression of subunit isoforms. Of particular interest is its feedback inhibition by ATP, the final product of OXPHOS. This "allosteric ATP-inhibition" of phosphorylated and dimeric COX maintains a low and healthy mitochondrial membrane potential (relaxed state), and prevents the formation of ROS (reactive oxygen species) which are known to cause numerous diseases. Excessive work and stress abolish this feedback inhibition of COX by Ca2+-activated dephosphorylation which leads to monomerization and movement of NDUFA4 from complex I to COX with higher rates of COX activity and ATP synthesis (active state) but increased ROS formation and decreased efficiency.
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Kadenbach B. Regulation of cytochrome c oxidase contributes to health and optimal life. World J Biol Chem 2020; 11:52-61. [PMID: 33024517 PMCID: PMC7520645 DOI: 10.4331/wjbc.v11.i2.52] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/16/2020] [Revised: 08/01/2020] [Accepted: 08/25/2020] [Indexed: 02/06/2023] Open
Abstract
The generation of cellular energy in the form of ATP occurs mainly in mitochondria by oxidative phosphorylation. Cytochrome c oxidase (CytOx), the oxygen accepting and rate-limiting step of the respiratory chain, regulates the supply of variable ATP demands in cells by “allosteric ATP-inhibition of CytOx.” This mechanism is based on inhibition of oxygen uptake of CytOx at high ATP/ADP ratios and low ferrocytochrome c concentrations in the mitochondrial matrix via cooperative interaction of the two substrate binding sites in dimeric CytOx. The mechanism keeps mitochondrial membrane potential ΔΨm and reactive oxygen species (ROS) formation at low healthy values. Stress signals increase cytosolic calcium leading to Ca2+-dependent dephosphorylation of CytOx subunit I at the cytosolic side accompanied by switching off the allosteric ATP-inhibition and monomerization of CytOx. This is followed by increase of ΔΨm and formation of ROS. A hypothesis is presented suggesting a dynamic change of binding of NDUFA4, originally identified as a subunit of complex I, between monomeric CytOx (active state with high ΔΨm, high ROS and low efficiency) and complex I (resting state with low ΔΨm, low ROS and high efficiency).
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Affiliation(s)
- Bernhard Kadenbach
- Department of Chemistry/Biochemistry, Fachbereich Chemie, Philipps-Universität Marburg, Marburg D-35043, Hessen, Germany
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10
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Vilhjálmsdóttir J, Albertsson I, Blomberg MRA, Ädelroth P, Brzezinski P. Proton transfer in uncoupled variants of cytochrome c oxidase. FEBS Lett 2019; 594:813-822. [PMID: 31725900 DOI: 10.1002/1873-3468.13679] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2019] [Revised: 10/31/2019] [Accepted: 11/09/2019] [Indexed: 11/08/2022]
Abstract
Cytochrome c oxidase is a membrane-bound redox-driven proton pump that harbors two proton-transfer pathways, D and K, which are used at different stages of the reaction cycle. Here, we address the question if a D pathway with a modified energy landscape for proton transfer could take over the role of the K pathway when the latter is blocked by a mutation. Our data indicate that structural alterations near the entrance of the D pathway modulate energy barriers that influence proton transfer to the proton-loading site. The data also suggest that during reduction of the catalytic site, its protonation has to occur via the K pathway and that this proton transfer to the catalytic site cannot take place through the D pathway.
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Affiliation(s)
- Jóhanna Vilhjálmsdóttir
- Department of Biochemistry and Biophysics, The Arrhenius Laboratories for Natural Sciences, Stockholm University, Sweden
| | - Ingrid Albertsson
- Department of Biochemistry and Biophysics, The Arrhenius Laboratories for Natural Sciences, Stockholm University, Sweden
| | - Margareta R A Blomberg
- Department of Organic Chemistry, The Arrhenius Laboratories for Natural Sciences, Stockholm University, Sweden
| | - Pia Ädelroth
- Department of Biochemistry and Biophysics, The Arrhenius Laboratories for Natural Sciences, Stockholm University, Sweden
| | - Peter Brzezinski
- Department of Biochemistry and Biophysics, The Arrhenius Laboratories for Natural Sciences, Stockholm University, Sweden
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11
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Salazar-Coria L, Rocha-Gómez MA, Matadamas-Martínez F, Yépez-Mulia L, Vega-López A. Proteomic analysis of oxidized proteins in the brain and liver of the Nile tilapia (Oreochromis niloticus) exposed to a water-accommodated fraction of Maya crude oil. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2019; 171:609-620. [PMID: 30658296 DOI: 10.1016/j.ecoenv.2019.01.033] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/01/2018] [Revised: 12/19/2018] [Accepted: 01/09/2019] [Indexed: 06/09/2023]
Abstract
Crude oil (CO) is a super mixture of chemical compounds whose toxic effects are reported in fish species according to international guidelines. In the current study a proteomic analysis of oxidized proteins (ox) was performed on the brain and liver of Nile tilapia exposed to WAF obtained from relevant environmental loads (0.01, 0.1 and 1.0 g/L) of Maya CO. Results have shown that oxidation of specific proteins was a newly discovered organ-dependent process able to disrupt key functions in Nile tilapia. In control fish, enzymes involved on aerobic metabolism (liver aldehyde dehydrogenase and brain dihydrofolate reductase) and liver tryptophan--tRNA ligase were oxidized. In WAF-treated liver specimens, fructose-bisphosphate aldolase (FBA), β-galactosidase (β-GAL) and dipeptidyl peptidase 9 (DPP-9) were detected in oxidized form. oxDPP-9 could be favorable by reducing the risk associated with altered glucose metabolism, the opposite effects elicited by oxFBA and oxβ-GAL. oxTrypsin showed a clear adverse effect by reducing probably the hepatocyte capacity to achieve proteolysis of oxidized proteins as well as for performing the proper digestive function. Additionally, enzyme implicated in purine metabolism adenosine (deaminase) was oxidized. Cerebral enzymes of mitochondrial respiratory chain complex (COX IV, COX5B), of glycosphingolipid biosynthesis (β-N-acetylhexosaminidase), involved in catecholamines degradation (catechol O-methyltransferase), and microtubule cytoskeleton (stathmin) were oxidized in WAF-treated specimens. This response suggests, in the brain, an adverse scenario for the mitochondrial respiration process and for ATP provision as for ischemia/reoxygenation challenges. Proteomic analysis of oxidized proteins is a promising tool for monitoring environmental quality influenced by hydrocarbons dissolved in water.
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Affiliation(s)
- Lucía Salazar-Coria
- Instituto Politécnico Nacional, Escuela Nacional de Ciencias Biológicas, Laboratorio de Toxicología Ambiental, Av. Wilfrido Massieu s/n, Unidad Profesional Zacatenco, 07738 Mexico City, Mexico
| | - María Alejandra Rocha-Gómez
- Instituto Politécnico Nacional, Escuela Nacional de Ciencias Biológicas, Laboratorio de Toxicología Ambiental, Av. Wilfrido Massieu s/n, Unidad Profesional Zacatenco, 07738 Mexico City, Mexico
| | - Félix Matadamas-Martínez
- Unidad de Investigación Médica en Enfermedades Infecciosas y Parasitarias, UMAE Hospital de Pediatría, Centro Médico Siglo XXI, Instituto Mexicano del Seguro Social, 06720 Mexico City, Mexico
| | - Lilián Yépez-Mulia
- Unidad de Investigación Médica en Enfermedades Infecciosas y Parasitarias, UMAE Hospital de Pediatría, Centro Médico Siglo XXI, Instituto Mexicano del Seguro Social, 06720 Mexico City, Mexico
| | - Armando Vega-López
- Instituto Politécnico Nacional, Escuela Nacional de Ciencias Biológicas, Laboratorio de Toxicología Ambiental, Av. Wilfrido Massieu s/n, Unidad Profesional Zacatenco, 07738 Mexico City, Mexico.
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12
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Araújo RS, Sousa KRS, Sousa FCB, Oliveira AC, Dourado LRB, Guimarães SEF, Silva W, Biagiotti D, Bayão GFV, Araujo AC. Effect of glycerin supplementation on the expression of antioxidant and mitochondrial genes in broilers. ANIMAL PRODUCTION SCIENCE 2019. [DOI: 10.1071/an16391] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Crude glycerin has been used as an alternative energy source in animal feeding and can thus change both the animal’s performance and the levels of gene expression related to energy production process and the antioxidant system, since the effect of glycerin depends on its degree of purity in the diet. The aim of this study was to evaluate the effect of crude glycerin inclusion (0, 6 and 12%) in the diet has on performance characteristics and mRNA abundance of genes associated with the mitochondrial function (uncoupling protein (UCP), cytochrome C oxidase subunit III (COX III) and adenine nucleotide transporter (ANT)) and those that combat the reactive oxygen species (superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPx)) in the liver and muscle of broilers at 42 days of age. Total RNA was extracted from the tissues, and cDNA was amplified using specific primers for the genes under study through real-time reverse transcription polymerase chain reaction; the endogenous gene used was β-actin. There was no difference between glycerin concentrations for weight gain, feed intake or feed conversion. Greater expression of UCP at muscle and higher GPx expression at liver were observed in broilers fed 12% glycerin. In conclusion, the addition of 12% glycerin to broiler diets increased the expression of UCP and GPx, but did not change broiler performance. Therefore, glycerin can be used as an alternative ingredient without losses.
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13
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Cai X, Haider K, Lu J, Radic S, Son CY, Cui Q, Gunner M. Network analysis of a proposed exit pathway for protons to the P-side of cytochrome c oxidase. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2018; 1859:997-1005. [DOI: 10.1016/j.bbabio.2018.05.010] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/13/2018] [Revised: 05/11/2018] [Accepted: 05/16/2018] [Indexed: 11/25/2022]
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14
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Regulation of mitochondrial respiration and ATP synthesis via cytochrome c oxidase. RENDICONTI LINCEI-SCIENZE FISICHE E NATURALI 2018. [DOI: 10.1007/s12210-018-0710-y] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
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15
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Vilhjálmsdóttir J, Gennis RB, Brzezinski P. The electron distribution in the "activated" state of cytochrome c oxidase. Sci Rep 2018; 8:7502. [PMID: 29760451 PMCID: PMC5951807 DOI: 10.1038/s41598-018-25779-w] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2017] [Accepted: 04/26/2018] [Indexed: 11/09/2022] Open
Abstract
Cytochrome c oxidase catalyzes reduction of O2 to H2O at a catalytic site that is composed of a copper ion and heme group. The reaction is linked to translocation of four protons across the membrane for each O2 reduced to water. The free energy associated with electron transfer to the catalytic site is unequal for the four electron-transfer events. Most notably, the free energy associated with reduction of the catalytic site in the oxidized cytochrome c oxidase (state O) is not sufficient for proton pumping across the energized membrane. Yet, this electron transfer is mechanistically linked to proton pumping. To resolve this apparent discrepancy, a high-energy oxidized state (denoted OH) was postulated and suggested to be populated only during catalytic turnover. The difference between states O and OH was suggested to be manifested in an elevated midpoint potential of CuB in the latter. This proposal predicts that one-electron reduction of cytochrome c oxidase after its oxidation would yield re-reduction of essentially only CuB. Here, we investigated this process and found ~5% and ~6% reduction of heme a3 and CuB, respectively, i.e. the apparent redox potentials for heme a3 and CuB are lower than that of heme a.
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Affiliation(s)
- Jóhanna Vilhjálmsdóttir
- Department of Biochemistry and Biophysics, The Arrhenius Laboratories for Natural Sciences, Stockholm University, SE-106 91, Stockholm, Sweden
| | - Robert B Gennis
- Department of Biochemistry, University of Illinois at Urbana Champaign, Urbana, Illinois, 61801, United States
| | - Peter Brzezinski
- Department of Biochemistry and Biophysics, The Arrhenius Laboratories for Natural Sciences, Stockholm University, SE-106 91, Stockholm, Sweden.
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16
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Zhou W, Liotta LA, Petricoin EF. The Warburg Effect and Mass Spectrometry-based Proteomic Analysis. Cancer Genomics Proteomics 2018. [PMID: 28647695 DOI: 10.21873/cgp.20032] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Compared to normal cells, cancer cells have a unique metabolism by performing lactic acid fermentation in the presence of oxygen, also known as the Warburg effect. Researchers have proposed several hypotheses to elucidate the phenomenon, but the mechanism is still an enigma. In this review, we discuss three typical models, such as "damaged mitochondria", "adaptation to hypoxia", and "cell proliferation requirement", as well as contributions from mass spectrometry analysis toward our understanding of the Warburg effect. Mass spectrometry analysis supports the "adaptation to hypoxia" model that cancer cells are using quasi-anaerobic fermentation to reduce oxygen consumption in vivo. We further propose that hypoxia is an early event and it plays a crucial role in carcinoma initiation and development.
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Affiliation(s)
- Weidong Zhou
- Center for Applied Proteomics and Molecular Medicine, George Mason University, Manassas, VA, U.S.A.
| | - Lance A Liotta
- Center for Applied Proteomics and Molecular Medicine, George Mason University, Manassas, VA, U.S.A
| | - Emanuel F Petricoin
- Center for Applied Proteomics and Molecular Medicine, George Mason University, Manassas, VA, U.S.A
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17
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Poiana F, von Ballmoos C, Gonska N, Blomberg MRA, Ädelroth P, Brzezinski P. Splitting of the O-O bond at the heme-copper catalytic site of respiratory oxidases. SCIENCE ADVANCES 2017; 3:e1700279. [PMID: 28630929 PMCID: PMC5473675 DOI: 10.1126/sciadv.1700279] [Citation(s) in RCA: 39] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/26/2017] [Accepted: 04/20/2017] [Indexed: 05/30/2023]
Abstract
Heme-copper oxidases catalyze the four-electron reduction of O2 to H2O at a catalytic site that is composed of a heme group, a copper ion (CuB), and a tyrosine residue. Results from earlier experimental studies have shown that the O-O bond is cleaved simultaneously with electron transfer from a low-spin heme (heme a/b), forming a ferryl state (PR ; Fe4+=O2-, CuB2+-OH-). We show that with the Thermus thermophilus ba3 oxidase, at low temperature (10°C, pH 7), electron transfer from the low-spin heme b to the catalytic site is faster by a factor of ~10 (τ ≅ 11 μs) than the formation of the PR ferryl (τ ≅110 μs), which indicates that O2 is reduced before the splitting of the O-O bond. Application of density functional theory indicates that the electron acceptor at the catalytic site is a high-energy peroxy state [Fe3+-O--O-(H+)], which is formed before the PR ferryl. The rates of heme b oxidation and PR ferryl formation were more similar at pH 10, indicating that the formation of the high-energy peroxy state involves proton transfer within the catalytic site, consistent with theory. The combined experimental and theoretical data suggest a general mechanism for O2 reduction by heme-copper oxidases.
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Affiliation(s)
- Federica Poiana
- Department of Biochemistry and Biophysics, Arrhenius Laboratories for Natural Sciences, Stockholm University, SE-106 91 Stockholm, Sweden
| | | | - Nathalie Gonska
- Department of Biochemistry and Biophysics, Arrhenius Laboratories for Natural Sciences, Stockholm University, SE-106 91 Stockholm, Sweden
| | - Margareta R. A. Blomberg
- Department of Organic Chemistry, Arrhenius Laboratories for Natural Sciences, Stockholm University, SE-106 91 Stockholm, Sweden
| | - Pia Ädelroth
- Department of Biochemistry and Biophysics, Arrhenius Laboratories for Natural Sciences, Stockholm University, SE-106 91 Stockholm, Sweden
| | - Peter Brzezinski
- Department of Biochemistry and Biophysics, Arrhenius Laboratories for Natural Sciences, Stockholm University, SE-106 91 Stockholm, Sweden
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18
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Berg J, Block S, Höök F, Brzezinski P. Single Proteoliposomes with E. coli
Quinol Oxidase: Proton Pumping without Transmembrane Leaks. Isr J Chem 2017. [DOI: 10.1002/ijch.201600138] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Affiliation(s)
- Johan Berg
- Department of Biochemistry and Biophysics, The Arrhenius Laboratories for Natural Sciences; Stockholm University; SE-106 91 Stockholm Sweden
| | - Stephan Block
- Department of Physics, Division of Biological Physics; Chalmers University of Technology; Göteborg SE-412 96 Sweden
| | - Fredrik Höök
- Department of Physics, Division of Biological Physics; Chalmers University of Technology; Göteborg SE-412 96 Sweden
| | - Peter Brzezinski
- Department of Biochemistry and Biophysics, The Arrhenius Laboratories for Natural Sciences; Stockholm University; SE-106 91 Stockholm Sweden
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19
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Graf S, Fedotovskaya O, Kao WC, Hunte C, Ädelroth P, Bott M, von Ballmoos C, Brzezinski P. Rapid Electron Transfer within the III-IV Supercomplex in Corynebacterium glutamicum. Sci Rep 2016; 6:34098. [PMID: 27682138 PMCID: PMC5040959 DOI: 10.1038/srep34098] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2016] [Accepted: 09/07/2016] [Indexed: 12/20/2022] Open
Abstract
Complex III in C. glutamicum has an unusual di-heme cyt. c1 and it co-purifies with complex IV in a supercomplex. Here, we investigated the kinetics of electron transfer within this supercomplex and in the cyt. aa3 alone (cyt. bc1 was removed genetically). In the reaction of the reduced cyt. aa3 with O2, we identified the same sequence of events as with other A-type oxidases. However, even though this reaction is associated with proton uptake, no pH dependence was observed in the kinetics. For the cyt. bc1-cyt. aa3 supercomplex, we observed that electrons from the c-hemes were transferred to CuA with time constants 0.1–1 ms. The b-hemes were oxidized with a time constant of 6.5 ms, indicating that this electron transfer is rate-limiting for the overall quinol oxidation/O2 reduction activity (~210 e−/s). Furthermore, electron transfer from externally added cyt. c to cyt. aa3 was significantly faster upon removal of cyt. bc1 from the supercomplex, suggesting that one of the c-hemes occupies a position near CuA. In conclusion, isolation of the III-IV-supercomplex allowed us to investigate the kinetics of electron transfer from the b-hemes, via the di-heme cyt. c1 and heme a to the heme a3-CuB catalytic site of cyt. aa3.
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Affiliation(s)
- Simone Graf
- Department of Biochemistry and Biophysics, The Arrhenius Laboratories for Natural Sciences, Stockholm University, SE-106 91 Stockholm, Sweden.,Department of Chemistry and Biochemistry, University of Bern, Freiestrasse 3, 3012 Bern, Switzerland
| | - Olga Fedotovskaya
- Department of Biochemistry and Biophysics, The Arrhenius Laboratories for Natural Sciences, Stockholm University, SE-106 91 Stockholm, Sweden
| | - Wei-Chun Kao
- Institute of Biochemistry and Molecular Biology, ZBMZ, Faculty of Medicine, BIOSS Centre for Biological Signalling Studies, University of Freiburg, 79104 Freiburg, Germany
| | - Carola Hunte
- Institute of Biochemistry and Molecular Biology, ZBMZ, Faculty of Medicine, BIOSS Centre for Biological Signalling Studies, University of Freiburg, 79104 Freiburg, Germany
| | - Pia Ädelroth
- Department of Biochemistry and Biophysics, The Arrhenius Laboratories for Natural Sciences, Stockholm University, SE-106 91 Stockholm, Sweden
| | - Michael Bott
- IBG-1: Biotechnology, Institute of Bio- and Geosciences, Forschungszentrum Jülich, Wilhelm-Johnen-Strasse, D-52425 Jülich, Germany
| | - Christoph von Ballmoos
- Department of Chemistry and Biochemistry, University of Bern, Freiestrasse 3, 3012 Bern, Switzerland
| | - Peter Brzezinski
- Department of Biochemistry and Biophysics, The Arrhenius Laboratories for Natural Sciences, Stockholm University, SE-106 91 Stockholm, Sweden
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20
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Xu W, Zeng Z, Jiang JH, Chang YT, Yuan L. Wahrnehmung der chemischen Prozesse in einzelnen Organellen mit niedermolekularen Fluoreszenzsonden. Angew Chem Int Ed Engl 2016. [DOI: 10.1002/ange.201510721] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Affiliation(s)
- Wang Xu
- State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering; Hunan University; Changsha 410082 Volksrepublik China
- Department of Chemistry and Medicinal Chemistry Programme; National University of Singapore; Singapore 117543 Singapur
- Laboratory of Bioimaging Probe Development, A*STAR; Singapur
- Department of Chemistry; Stanford University; USA
| | - Zebing Zeng
- State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering; Hunan University; Changsha 410082 Volksrepublik China
| | - Jian-Hui Jiang
- State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering; Hunan University; Changsha 410082 Volksrepublik China
| | - Young-Tae Chang
- Department of Chemistry and Medicinal Chemistry Programme; National University of Singapore; Singapore 117543 Singapur
- Laboratory of Bioimaging Probe Development, A*STAR; Singapur
| | - Lin Yuan
- State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering; Hunan University; Changsha 410082 Volksrepublik China
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21
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Xu W, Zeng Z, Jiang JH, Chang YT, Yuan L. Discerning the Chemistry in Individual Organelles with Small-Molecule Fluorescent Probes. Angew Chem Int Ed Engl 2016; 55:13658-13699. [DOI: 10.1002/anie.201510721] [Citation(s) in RCA: 526] [Impact Index Per Article: 65.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2015] [Indexed: 12/22/2022]
Affiliation(s)
- Wang Xu
- State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering; Hunan University; Changsha 410082 P.R. China
- Department of Chemistry and Medicinal Chemistry Programme; National University of Singapore; Singapore 117543 Singapore
- Laboratory of Bioimaging Probe Development, A*STAR; Singapore
- Department of Chemistry; Stanford University; USA
| | - Zebing Zeng
- State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering; Hunan University; Changsha 410082 P.R. China
| | - Jian-Hui Jiang
- State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering; Hunan University; Changsha 410082 P.R. China
| | - Young-Tae Chang
- Department of Chemistry and Medicinal Chemistry Programme; National University of Singapore; Singapore 117543 Singapore
- Laboratory of Bioimaging Probe Development, A*STAR; Singapore
| | - Lin Yuan
- State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering; Hunan University; Changsha 410082 P.R. China
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22
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Vilhjálmsdóttir J, Johansson AL, Brzezinski P. Structural Changes and Proton Transfer in Cytochrome c Oxidase. Sci Rep 2015; 5:12047. [PMID: 26310633 PMCID: PMC4550891 DOI: 10.1038/srep12047] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2015] [Accepted: 06/16/2015] [Indexed: 01/28/2023] Open
Abstract
In cytochrome c oxidase electron transfer from cytochrome c to O2 is linked to transmembrane proton pumping, which contributes to maintaining a proton electrochemical gradient across the membrane. The mechanism by which cytochrome c oxidase couples the exergonic electron transfer to the endergonic proton translocation is not known, but it presumably involves local structural changes that control the alternating proton access to the two sides of the membrane. Such redox-induced structural changes have been observed in X-ray crystallographic studies at residues 423-425 (in the R. sphaeroides oxidase), located near heme a. The aim of the present study is to investigate the functional effects of these structural changes on reaction steps associated with proton pumping. Residue Ser425 was modified using site-directed mutagenesis and time-resolved spectroscopy was used to investigate coupled electron-proton transfer upon reaction of the oxidase with O2. The data indicate that the structural change at position 425 propagates to the D proton pathway, which suggests a link between redox changes at heme a and modulation of intramolecular proton-transfer rates.
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Affiliation(s)
- Jóhanna Vilhjálmsdóttir
- Department of Biochemistry and Biophysics, The Arrhenius Laboratories for Natural Sciences, Stockholm University, SE-106 91 Stockholm, Sweden
| | - Ann-Louise Johansson
- Department of Biochemistry and Biophysics, The Arrhenius Laboratories for Natural Sciences, Stockholm University, SE-106 91 Stockholm, Sweden
| | - Peter Brzezinski
- Department of Biochemistry and Biophysics, The Arrhenius Laboratories for Natural Sciences, Stockholm University, SE-106 91 Stockholm, Sweden
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23
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Kadenbach B, Hüttemann M. The subunit composition and function of mammalian cytochrome c oxidase. Mitochondrion 2015; 24:64-76. [PMID: 26190566 DOI: 10.1016/j.mito.2015.07.002] [Citation(s) in RCA: 156] [Impact Index Per Article: 17.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2015] [Revised: 07/03/2015] [Accepted: 07/08/2015] [Indexed: 12/31/2022]
Abstract
Cytochrome c oxidase (COX) from mammals and birds is composed of 13 subunits. The three catalytic subunits I-III are encoded by mitochondrial DNA, the ten nuclear-coded subunits (IV, Va, Vb, VIa, VIb, VIc, VIIa, VIIb, VIIc, VIII) by nuclear DNA. The nuclear-coded subunits are essentially involved in the regulation of oxygen consumption and proton translocation by COX, since their removal or modification changes the activity and their mutation causes mitochondrial diseases. Respiration, the basis for ATP synthesis in mitochondria, is differently regulated in organs and species by expression of tissue-, developmental-, and species-specific isoforms for COX subunits IV, VIa, VIb, VIIa, VIIb, and VIII, but the holoenzyme in mammals is always composed of 13 subunits. Various proteins and enzymes were shown, e.g., by co-immunoprecipitation, to bind to specific COX subunits and modify its activity, but these interactions are reversible, in contrast to the tightly bound 13 subunits. In addition, the formation of supercomplexes with other oxidative phosphorylation complexes has been shown to be largely variable. The regulatory complexity of COX is increased by protein phosphorylation. Up to now 18 phosphorylation sites have been identified under in vivo conditions in mammals. However, only for a few phosphorylation sites and four nuclear-coded subunits could a specific function be identified. Research on the signaling pathways leading to specific COX phosphorylations remains a great challenge for understanding the regulation of respiration and ATP synthesis in mammalian organisms. This article reviews the function of the individual COX subunits and their isoforms, as well as proteins and small molecules interacting and regulating the enzyme.
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Affiliation(s)
| | - Maik Hüttemann
- Center for Molecular Medicine and Genetics, Wayne State University School of Medicine, Detroit, MI 48201, USA
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24
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Kadenbach B. Der Mensch, ein elektrisches Wesen. CHEM UNSERER ZEIT 2015. [DOI: 10.1002/ciuz.201500693] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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25
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Mutation of a single residue in the ba3 oxidase specifically impairs protonation of the pump site. Proc Natl Acad Sci U S A 2015; 112:3397-402. [PMID: 25733886 DOI: 10.1073/pnas.1422434112] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
The ba3-type cytochrome c oxidase from Thermus thermophilus is a membrane-bound protein complex that couples electron transfer to O2 to proton translocation across the membrane. To elucidate the mechanism of the redox-driven proton pumping, we investigated the kinetics of electron and proton transfer in a structural variant of the ba3 oxidase where a putative "pump site" was modified by replacement of Asp372 by Ile. In this structural variant, proton pumping was uncoupled from internal electron transfer and O2 reduction. The results from our studies show that proton uptake to the pump site (time constant ∼65 μs in the wild-type cytochrome c oxidase) was impaired in the Asp372Ile variant. Furthermore, a reaction step that in the wild-type cytochrome c oxidase is linked to simultaneous proton uptake and release with a time constant of ∼1.2 ms was slowed to ∼8.4 ms, and in Asp372Ile was only associated with proton uptake to the catalytic site. These data identify reaction steps that are associated with protonation and deprotonation of the pump site, and point to the area around Asp372 as the location of this site in the ba3 cytochrome c oxidase.
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26
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Svahn E, Faxén K, Gennis RB, Brzezinski P. Proton pumping by an inactive structural variant of cytochrome c oxidase. J Inorg Biochem 2014; 140:6-11. [PMID: 25042731 DOI: 10.1016/j.jinorgbio.2014.06.016] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2014] [Revised: 06/23/2014] [Accepted: 06/23/2014] [Indexed: 12/12/2022]
Abstract
The aa3-type cytochrome c oxidases (CytcOs) from e.g. Rhodobacter sphaeroides and Paracoccus denitrificans harbor two proton-transfer pathways. The K pathway is used for proton uptake upon reduction of the CytcO, while the D pathway is used after binding of O2 to the catalytic site. The aim of the present study was to determine whether or not CytcO in which the K pathway is blocked (by e.g. the Lys362Met replacement) is capable of pumping protons. The process can not be studied using conventional assays because the O2-reduction activity is too low when the K pathway is blocked. Consequently, proton pumping with a blocked K pathway has not been demonstrated directly. Here, the Lys362Met and Ser299Glu structural variants were reconstituted in liposomes and allowed to (slowly) become completely reduced. Then, the reaction with O2 was studied with μs time resolution after flash photolysis of a blocking CO ligand bound to heme a3. The data show that with both the inactive Lys362Met and partly active Ser299Glu variants proton release occurred with the same time constants as with the wild-type oxidase, i.e. ~200μs and ~3ms, corresponding in time to formation of the ferryl and oxidized states, respectively. Thus, the data show that the K pathway is not required for proton pumping, suggesting that D and K pathways operate independently of each other after binding of O2 to the catalytic site.
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Affiliation(s)
- Emelie Svahn
- Department of Biochemistry and Biophysics, The Arrhenius Laboratories for Natural Sciences, Stockholm University, SE-106 91 Stockholm, Sweden
| | - Kristina Faxén
- Department of Biochemistry and Biophysics, The Arrhenius Laboratories for Natural Sciences, Stockholm University, SE-106 91 Stockholm, Sweden
| | - Robert B Gennis
- Department of Biochemistry, University of Illinois at Urbana Champaign, Urbana, IL 61801, United States
| | - Peter Brzezinski
- Department of Biochemistry and Biophysics, The Arrhenius Laboratories for Natural Sciences, Stockholm University, SE-106 91 Stockholm, Sweden.
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27
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Solomon EI, Heppner DE, Johnston EM, Ginsbach JW, Cirera J, Qayyum M, Kieber-Emmons MT, Kjaergaard CH, Hadt RG, Tian L. Copper active sites in biology. Chem Rev 2014; 114:3659-853. [PMID: 24588098 PMCID: PMC4040215 DOI: 10.1021/cr400327t] [Citation(s) in RCA: 1138] [Impact Index Per Article: 113.8] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Affiliation(s)
| | - David E. Heppner
- Department of Chemistry, Stanford University, Stanford, CA, 94305
| | | | - Jake W. Ginsbach
- Department of Chemistry, Stanford University, Stanford, CA, 94305
| | - Jordi Cirera
- Department of Chemistry, Stanford University, Stanford, CA, 94305
| | - Munzarin Qayyum
- Department of Chemistry, Stanford University, Stanford, CA, 94305
| | | | | | - Ryan G. Hadt
- Department of Chemistry, Stanford University, Stanford, CA, 94305
| | - Li Tian
- Department of Chemistry, Stanford University, Stanford, CA, 94305
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28
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Näsvik Öjemyr L, Maréchal A, Vestin H, Meunier B, Rich PR, Brzezinski P. Reaction of wild-type and Glu243Asp variant yeast cytochrome c oxidase with O2. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2014; 1837:1012-8. [PMID: 24685432 DOI: 10.1016/j.bbabio.2014.03.012] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/05/2013] [Revised: 03/07/2014] [Accepted: 03/21/2014] [Indexed: 11/29/2022]
Abstract
We have studied internal electron transfer during the reaction of Saccharomyces cerevisiae mitochondrial cytochrome c oxidase with dioxygen. Similar absorbance changes were observed with this yeast oxidase as with the previously studied Rhodobacter sphaeroides and bovine mitochondrial oxidases, which suggests that the reaction proceeds along the same trajectory. However, notable differences were observed in rates and electron-transfer equilibrium constants of specific reaction steps, for example the ferryl (F) to oxidized (O) reaction was faster with the yeast (0.4ms) than with the bovine oxidase (~1ms) and a larger fraction CuA was oxidized with the yeast than with the bovine oxidase in the peroxy (PR) to F reaction. Furthermore, upon replacement of Glu243, located at the end of the so-called D proton pathway, by Asp the PR→F and F→O reactions were slowed by factors of ~3 and ~10, respectively, and electron transfer from CuA to heme a during the PR→F reaction was not observed. These data indicate that during reduction of dioxygen protons are transferred through the D pathway, via Glu243, to the catalytic site in the yeast mitochondrial oxidase. This article is part of a Special Issue entitled: 18th European Bioenergetic Conference.
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Affiliation(s)
- Linda Näsvik Öjemyr
- Department of Biochemistry and Biophysics, The Arrhenius Laboratories for Natural Sciences, Stockholm University, SE-106 91 Stockholm, Sweden
| | - Amandine Maréchal
- Glynn Laboratory of Bioenergetics, Institute of Structural and Molecular Biology, University College London, Gower Street, London WC1E 6BT, UK
| | - Henrik Vestin
- Department of Biochemistry and Biophysics, The Arrhenius Laboratories for Natural Sciences, Stockholm University, SE-106 91 Stockholm, Sweden
| | - Brigitte Meunier
- Centre de Génétique Moléculaire du CNRS, UPR 3404, avenue de la Terrasse, 91198 Gif-sur-Yvette Cedex, France
| | - Peter R Rich
- Glynn Laboratory of Bioenergetics, Institute of Structural and Molecular Biology, University College London, Gower Street, London WC1E 6BT, UK
| | - Peter Brzezinski
- Department of Biochemistry and Biophysics, The Arrhenius Laboratories for Natural Sciences, Stockholm University, SE-106 91 Stockholm, Sweden.
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Terasaka E, Okada N, Sato N, Sako Y, Shiro Y, Tosha T. Characterization of quinol-dependent nitric oxide reductase from Geobacillus stearothermophilus: enzymatic activity and active site structure. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2014; 1837:1019-26. [PMID: 24569054 DOI: 10.1016/j.bbabio.2014.02.017] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/21/2013] [Revised: 02/10/2014] [Accepted: 02/15/2014] [Indexed: 10/25/2022]
Abstract
Nitric oxide reductase (NOR) catalyzes the reduction of nitric oxide to generate nitrous oxide. We recently reported on the crystal structure of a quinol-dependent NOR (qNOR) from Geobacillus stearothermophilus [Y. Matsumoto, T. Tosha, A.V. Pisliakov, T. Hino, H. Sugimoto, S. Nagano, Y. Sugita and Y. Shiro, Nat. Struct. Mol. Biol. 19 (2012) 238-246], and suggested that a water channel from the cytoplasm, which is not observed in cytochrome c-dependent NOR (cNOR), functions as a pathway transferring catalytic protons. Here, we further investigated the functional and structural properties of qNOR, and compared the findings with those for cNOR. The pH optimum for the enzymatic reaction of qNOR was in the alkaline range, whereas Pseudomonas aeruginosa cNOR showed a higher activity at an acidic pH. The considerably slower reduction rate, and a correlation of the pH dependence for enzymatic activity and the reduction rate suggest that the reduction process is the rate-determining step for the NO reduction by qNOR, while the reduction rate for cNOR was very fast and therefore is unlikely to be the rate-determining step. A close examination of the heme/non-heme iron binuclear center by resonance Raman spectroscopy indicated that qNOR has a more polar environment at the binuclear center compared with cNOR. It is plausible that a water channel enhances the accessibility of the active site to solvent water, creating a more polar environment in qNOR. This structural feature could control certain properties of the active site, such as redox potential, which could explain the different catalytic properties of the two NORs. This article is part of a Special Issue entitled: 18th European Bioenergetic Conference.
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Affiliation(s)
- Erina Terasaka
- RIKEN SPring-8 Center, Kouto, Sayo, Hyogo 679-5148, Japan; Graduate School of Life Science, University of Hyogo, Hyogo 678-1297, Japan
| | - Norihiro Okada
- RIKEN SPring-8 Center, Kouto, Sayo, Hyogo 679-5148, Japan; Graduate School of Life Science, University of Hyogo, Hyogo 678-1297, Japan
| | - Nozomi Sato
- RIKEN SPring-8 Center, Kouto, Sayo, Hyogo 679-5148, Japan; Division of Applied Biosciences, Graduate School of Agriculture, Kyoto University, Kyoto 606-8502, Japan
| | - Yoshihiko Sako
- Division of Applied Biosciences, Graduate School of Agriculture, Kyoto University, Kyoto 606-8502, Japan
| | - Yoshitsugu Shiro
- RIKEN SPring-8 Center, Kouto, Sayo, Hyogo 679-5148, Japan; Graduate School of Life Science, University of Hyogo, Hyogo 678-1297, Japan.
| | - Takehiko Tosha
- RIKEN SPring-8 Center, Kouto, Sayo, Hyogo 679-5148, Japan.
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30
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Sato N, Ishii S, Sugimoto H, Hino T, Fukumori Y, Sako Y, Shiro Y, Tosha T. Structures of reduced and ligand-bound nitric oxide reductase provide insights into functional differences in respiratory enzymes. Proteins 2014; 82:1258-71. [PMID: 24338896 DOI: 10.1002/prot.24492] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2013] [Revised: 11/27/2013] [Accepted: 12/09/2013] [Indexed: 11/07/2022]
Abstract
Nitric oxide reductase (NOR) catalyzes the generation of nitrous oxide (N2O) via the reductive coupling of two nitric oxide (NO) molecules at a heme/non-heme Fe center. We report herein on the structures of the reduced and ligand-bound forms of cytochrome c-dependent NOR (cNOR) from Pseudomonas aeruginosa at a resolution of 2.3-2.7 Å, to elucidate structure-function relationships in NOR, and compare them to those of cytochrome c oxidase (CCO) that is evolutionarily related to NOR. Comprehensive crystallographic refinement of the CO-bound form of cNOR suggested that a total of four atoms can be accommodated at the binuclear center. Consistent with this, binding of bulky acetaldoxime (CH3-CH=N-OH) to the binuclear center of cNOR was confirmed by the structural analysis. Active site reduction and ligand binding in cNOR induced only ∼0.5 Å increase in the heme/non-heme Fe distance, but no significant structural change in the protein. The highly localized structural change is consistent with the lack of proton-pumping activity in cNOR, because redox-coupled conformational changes are thought to be crucial for proton pumping in CCO. It also permits the rapid decomposition of cytotoxic NO in denitrification. In addition, the shorter heme/non-heme Fe distance even in the bulky ligand-bound form of cNOR (∼4.5 Å) than the heme/Cu distance in CCO (∼5 Å) suggests the ability of NOR to maintain two NO molecules within a short distance in the confined space of the active site, thereby facilitating N-N coupling to produce a hyponitrite intermediate for the generation of N2O.
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Affiliation(s)
- Nozomi Sato
- Biometal Science Laboratory, RIKEN SPring-8 Center, Kouto, Sayo, Hyogo 679-5148, Japan; Division of Applied Biosciences, Graduate School of Agriculture, Kyoto University, Kyoto 606-8502, Japan
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31
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Brzezinski P, Öjemyr LN, Ädelroth P. Intermediates generated during the reaction of reduced Rhodobacter sphaeroides cytochrome c oxidase with dioxygen. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2013; 1827:843-7. [DOI: 10.1016/j.bbabio.2013.04.007] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/07/2013] [Revised: 04/18/2013] [Accepted: 04/23/2013] [Indexed: 10/26/2022]
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Maréchal A, Iwaki M, Rich PR. Structural Changes in Cytochrome c Oxidase Induced by Binding of Sodium and Calcium Ions: An ATR-FTIR Study. J Am Chem Soc 2013; 135:5802-7. [DOI: 10.1021/ja4005706] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Amandine Maréchal
- Glynn Laboratory of
Bioenergetics,
Institute of Structural and Molecular Biology, University College London, Gower Street, London, WC1E 6BT, United
Kingdom
| | - Masayo Iwaki
- Glynn Laboratory of
Bioenergetics,
Institute of Structural and Molecular Biology, University College London, Gower Street, London, WC1E 6BT, United
Kingdom
| | - Peter R. Rich
- Glynn Laboratory of
Bioenergetics,
Institute of Structural and Molecular Biology, University College London, Gower Street, London, WC1E 6BT, United
Kingdom
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33
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Johansson AL, Carlsson J, Högbom M, Hosler JP, Gennis RB, Brzezinski P. Proton uptake and pKa changes in the uncoupled Asn139Cys variant of cytochrome c oxidase. Biochemistry 2013; 52:827-36. [PMID: 23305515 DOI: 10.1021/bi301597a] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Cytochrome c oxidase (CytcO) is a membrane-bound enzyme that links electron transfer from cytochrome c to O(2) to proton pumping across the membrane. Protons are transferred through specific pathways that connect the protein surface with the catalytic site as well as the proton input with the proton output sides. Results from earlier studies have shown that one site within the so-called D proton pathway, Asn139, located ~10 Å from the protein surface, is particularly sensitive to mutations that uncouple the O(2) reduction reaction from the proton pumping activity. For example, none of the Asn139Asp (charged) or Asn139Thr (neutral) mutant CytcOs pump protons, although the proton-uptake rates are unaffected. Here, we have investigated the Asn139Cys and Asn139Cys/Asp132Asn mutant CytcOs. In contrast to other structural variants investigated to date, the Cys side chain may be either neutral or negatively charged in the experimentally accessible pH range. The data show that the Asn139Cys and Asn139Asp mutations result in the same changes of the kinetic and thermodynamic parameters associated with the proton transfer. The similarity is not due to introduction of charge at position 139, but rather introduction of a protonatable group that modulates the proton connectivity around this position. These results illuminate the mechanism by which CytcO couples electron transfer to proton pumping.
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Affiliation(s)
- Ann-Louise Johansson
- Department of Biochemistry and Biophysics, The Arrhenius Laboratories for Natural Sciences, Stockholm University, Stockholm, Sweden
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34
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High efficiency versus maximal performance--the cause of oxidative stress in eukaryotes: a hypothesis. Mitochondrion 2012. [PMID: 23178790 DOI: 10.1016/j.mito.2012.11.005] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Degenerative diseases are in part based on elevated production of ROS (reactive oxygen species) in mitochondria, mainly during stress and excessive work under stress (strenuous exercise). The production of ROS increases with increasing mitochondrial membrane potential (ΔΨ(m)). A mechanism is described which is suggested to keep ΔΨ(m) at low values under normal conditions thus preventing ROS formation, but is switched off under stress and excessive work to maximize the rate of ATP synthesis, accompanied by decreased efficiency. Low ΔΨ(m) and low ROS production are suggested to occur by inhibition of respiration at high [ATP]/[ADP] ratios. The nucleotides interact with phosphorylated cytochrome c oxidase (COX), representing the step with the highest flux-control coefficient of mitochondrial respiration. At stress and excessive work neural signals are suggested to dephosphorylate the enzyme and abolish the control of COX activity (respiration) by the [ATP]/[ADP] ratio with consequent increase of ΔΨ(m) and ROS production. The control of COX by the [ATP]/[ADP] ratio, in addition, is proposed to increase the efficiency of ATP production via a third proton pumping pathway, identified in eukaryotic but not in prokaryotic COX. We conclude that 'oxidative stress' occurs when the control of COX activity by the [ATP]/[ADP] ratio is switched off via neural signals.
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35
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Soto IC, Fontanesi F, Liu J, Barrientos A. Biogenesis and assembly of eukaryotic cytochrome c oxidase catalytic core. BIOCHIMICA ET BIOPHYSICA ACTA 2012; 1817:883-97. [PMID: 21958598 PMCID: PMC3262112 DOI: 10.1016/j.bbabio.2011.09.005] [Citation(s) in RCA: 159] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/10/2011] [Revised: 09/07/2011] [Accepted: 09/12/2011] [Indexed: 10/17/2022]
Abstract
Eukaryotic cytochrome c oxidase (COX) is the terminal enzyme of the mitochondrial respiratory chain. COX is a multimeric enzyme formed by subunits of dual genetic origin which assembly is intricate and highly regulated. The COX catalytic core is formed by three mitochondrial DNA encoded subunits, Cox1, Cox2 and Cox3, conserved in the bacterial enzyme. Their biogenesis requires the action of messenger-specific and subunit-specific factors which facilitate the synthesis, membrane insertion, maturation or assembly of the core subunits. The study of yeast strains and human cell lines from patients carrying mutations in structural subunits and COX assembly factors has been invaluable to identify these ancillary factors. Here we review the current state of knowledge of the biogenesis and assembly of the eukaryotic COX catalytic core and discuss the degree of conservation of the players and mechanisms operating from yeast to human. This article is part of a Special Issue entitled: Biogenesis/Assembly of Respiratory Enzyme Complexes.
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Affiliation(s)
- Ileana C. Soto
- Department of Biochemistry & Molecular Biology, University of Miami Miller School of Medicine. Miami, FL
| | - Flavia Fontanesi
- Department of Neurology. University of Miami Miller School of Medicine. Miami, FL
| | - Jingjing Liu
- Department of Biochemistry & Molecular Biology, University of Miami Miller School of Medicine. Miami, FL
| | - Antoni Barrientos
- Department of Biochemistry & Molecular Biology, University of Miami Miller School of Medicine. Miami, FL
- Department of Neurology. University of Miami Miller School of Medicine. Miami, FL
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36
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Peng Y, Voth GA. Expanding the view of proton pumping in cytochrome c oxidase through computer simulation. BIOCHIMICA ET BIOPHYSICA ACTA 2012; 1817:518-25. [PMID: 22178790 PMCID: PMC4120846 DOI: 10.1016/j.bbabio.2011.11.017] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/01/2011] [Revised: 11/23/2011] [Accepted: 11/24/2011] [Indexed: 01/01/2023]
Abstract
In cytochrome c oxidase (CcO), a redox-driven proton pump, protons are transported by the Grotthuss shuttling via hydrogen-bonded water molecules and protonatable residues. Proton transport through the D-pathway is a complicated process that is highly sensitive to alterations in the amino acids or the solvation structure in the channel, both of which can inhibit proton pumping and enzymatic activity. Simulations of proton transport in the hydrophobic cavity showed a clear redox state dependence. To study the mechanism of proton pumping in CcO, multi-state empirical valence bond (MS-EVB) simulations have been conducted, focusing on the proton transport through the D-pathway and the hydrophobic cavity next to the binuclear center. The hydration structures, transport pathways, effects of residues, and free energy surfaces of proton transport were revealed in these MS-EVB simulations. The mechanistic insight gained from them is herein reviewed and placed in context for future studies.
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Affiliation(s)
- Yuxing Peng
- Department of Chemistry, James Franck Institute, Institute for Biophysical Dynamics, and Computation Institute, University of Chicago, 5735 South Ellis Avenue, Chicago, IL 60637, USA
| | - Gregory A. Voth
- Department of Chemistry, James Franck Institute, Institute for Biophysical Dynamics, and Computation Institute, University of Chicago, 5735 South Ellis Avenue, Chicago, IL 60637, USA
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37
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Exploring the proton pump and exit pathway for pumped protons in cytochrome ba3 from Thermus thermophilus. Proc Natl Acad Sci U S A 2012; 109:5259-64. [PMID: 22431640 DOI: 10.1073/pnas.1107345109] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The heme-copper oxygen reductases are redox-driven proton pumps. In the current work, the effects of mutations in a proposed exit pathway for pumped protons are examined in the ba(3)-type oxygen reductase from Thermus thermophilus, leading from the propionates of heme a(3) to the interface between subunits I and II. Recent studies have proposed important roles for His376 and Asp372, both of which are hydrogen-bonded to propionate-A of heme a(3), and for Glu126(II) (subunit II), which is hydrogen-bonded to His376. Based on the current results, His376, Glu126(II), and Asp372 are not essential for either oxidase activity or proton pumping. In addition, Tyr133, which is hydrogen-bonded to propionate-D of heme a(3), was also shown not to be essential for function. However, two mutations of the residues hydrogen-bonded to propionate-A, Asp372Ile and His376Asn, retain high electron transfer activity and normal spectral features but, in different preparations, either do not pump protons or exhibit substantially diminished proton pumping. It is concluded that either propionate-A of heme a(3) or possibly the cluster of groups centered about the conserved water molecule that hydrogen-bonds to both propionates-A and -D of heme a(3) is a good candidate to be the proton loading site.
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38
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Öjemyr LN, von Ballmoos C, Faxén K, Svahn E, Brzezinski P. The membrane modulates internal proton transfer in cytochrome c oxidase. Biochemistry 2012; 51:1092-100. [PMID: 22257086 DOI: 10.1021/bi201795c] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The functionality of membrane proteins is often modulated by the surrounding membrane. Here, we investigated the effect of membrane reconstitution of purified cytochrome c oxidase (CytcO) on the kinetics and thermodynamics of internal electron and proton-transfer reactions during O(2) reduction. Reconstitution of the detergent-solubilized enzyme in small unilamellar soybean phosphatidylcholine vesicles resulted in a lowering of the pK(a) in the pH dependence profile of the proton-uptake rate. This pK(a) change resulted in decreased proton-uptake rates in the pH range of ~6.5-9.5, which is explained in terms of lowering of the pK(a) of an internal proton donor within CytcO. At pH 7.5, the rate decreased to the same extent when vesicles were prepared from the pure zwitterionic lipid 1,2-dioleoyl-sn-glycero-3-phosphocholine (DOPC) or the anionic lipid 1,2-dioleoyl-sn-glycero-3-phospho(1-rac-glycerol) (DOPG). In addition, a small change in the internal Cu(A)-heme a electron equilibrium constant was observed. This effect was lipid-dependent and explained in terms of a lower electrostatic potential within the membrane-spanning part of the protein with the anionic DOPG lipids than with the zwitterionic DOPC lipids. In conclusion, the data show that the membrane significantly modulates internal charge-transfer reactions and thereby the function of the membrane-bound enzyme.
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Affiliation(s)
- Linda Näsvik Öjemyr
- Department of Biochemistry and Biophysics, The Arrhenius Laboratories for Natural Sciences, Stockholm University, SE-106 91 Stockholm, Sweden
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39
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Kadenbach B. Introduction to mitochondrial oxidative phosphorylation. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2012; 748:1-11. [PMID: 22729852 DOI: 10.1007/978-1-4614-3573-0_1] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
The basic mechanism of ATP synthesis in the mitochondria by oxidative phosphorylation (OxPhos) was revealed in the second half of the twentieth century. The OxPhos complexes I-V have been analyzed concerning their subunit composition, genes, and X-ray structures. This book presents new developments regarding the morphology, biogenesis, gene evolution, heat, and reactive oxygen species (ROS) generation in mitochondria, as well as the structure and supercomplex formation of OxPhos complexes. In addition, multiple mitochondrial diseases based on mutations of nuclear-encoded genes have been identified. Little is known, however, of the regulation of OxPhos according to the variable cellular demands of ATP. In particular, the functions of the supernumerary (nuclear-encoded) subunits of mitochondrial OxPhos complexes, which are mostly absent in bacteria, remain largely unknown, although the corresponding and conserved core subunits exhibit the same catalytic activity. Identification of regulatory pathways modulating OxPhos activity, by subunit isoform expression, by allosteric interaction with ATP/ADP, by reversible phosphorylation of protein subunits, or by supercomplex formation, will help to understand the role of mitochondria in the many degenerative diseases, mostly based on ROS formation in mitochondria and/or insufficient energy production.
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40
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Kim HK, Thu VT, Heo HJ, Kim N, Han J. Cardiac proteomic responses to ischemia-reperfusion injury and ischemic preconditioning. Expert Rev Proteomics 2011; 8:241-61. [PMID: 21501017 DOI: 10.1586/epr.11.8] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Cardiac ischemia and ischemia-reperfusion (I/R) injury are major contributors to morbidity and mortality worldwide. Pathological mechanisms of I/R and the physiological mechanisms of ischemic preconditioning (IPC), which is an effective cardiac protective response, have been widely investigated in the last decade to search for means to prevent or treat this disease. Proteomics is a powerful analytical tool that has provided important information to identify target proteins and understand the underlying mechanisms of I/R and IPC. Here, we review the application of proteomics to I/R injury and IPC to discover target proteins. We analyze the functional meaning of the accumulated data on hundreds of proteins using various bioinformatics applications. In addition, we review exercise-induced proteomic alterations in the heart to understand the potential cardioprotective role of exercise against I/R injury. Further developments in the proteomic field that target specialized proteins will yield new insights for optimizing therapeutic targets and developing a wide range of therapeutic agents against ischemic heart disease.
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Affiliation(s)
- Hyoung Kyu Kim
- National Research Laboratory for Mitochondrial Signaling, Department of Physiology, College of Medicine, Cardiovascular and Metabolic Disease Center, Inje University 633-165 Gaegeum-Dong, Busanjin-Gu, Busan 613-735, Korea
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41
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Functional interactions between membrane-bound transporters and membranes. Proc Natl Acad Sci U S A 2010; 107:15763-7. [PMID: 20798065 DOI: 10.1073/pnas.1006109107] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
One key role of many cellular membranes is to hold a transmembrane electrochemical ion gradient that stores free energy, which is used, for example, to generate ATP or to drive transmembrane transport processes. In mitochondria and many bacteria, the gradient is maintained by proton-transport proteins that are part of the respiratory (electron-transport) chain. Even though our understanding of the structure and function of these proteins has increased significantly, very little is known about the specific role of functional protein-membrane and membrane-mediated protein-protein interactions. Here, we have investigated the effect of membrane incorporation on proton-transfer reactions within the membrane-bound proton pump cytochrome c oxidase. The results show that the membrane acts to accelerate proton transfer into the enzyme's catalytic site and indicate that the intramolecular proton pathway is wired via specific amino acid residues to the two-dimensional space defined by the membrane surface. We conclude that the membrane not only acts as a passive barrier insulating the interior of the cell from the exterior solution, but also as a component of the energy-conversion machinery.
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42
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Kuznetsov A, Ulstrup J. Proton and proton-coupled electron transfer with paradigms towards single-molecule systems. J PHYS ORG CHEM 2010. [DOI: 10.1002/poc.1724] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
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43
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Brzezinski P, Johansson AL. Variable proton-pumping stoichiometry in structural variants of cytochrome c oxidase. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2010; 1797:710-23. [DOI: 10.1016/j.bbabio.2010.02.020] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/21/2010] [Revised: 02/15/2010] [Accepted: 02/17/2010] [Indexed: 10/19/2022]
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44
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Muramoto K, Ohta K, Shinzawa-Itoh K, Kanda K, Taniguchi M, Nabekura H, Yamashita E, Tsukihara T, Yoshikawa S. Bovine cytochrome c oxidase structures enable O2 reduction with minimization of reactive oxygens and provide a proton-pumping gate. Proc Natl Acad Sci U S A 2010; 107:7740-5. [PMID: 20385840 PMCID: PMC2867921 DOI: 10.1073/pnas.0910410107] [Citation(s) in RCA: 113] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The O(2) reduction site of cytochrome c oxidase (CcO), comprising iron (Fe(a3)) and copper (Cu(B)) ions, is probed by x-ray structural analyses of CO, NO, and CN(-) derivatives to investigate the mechanism of the complete reduction of O(2). Formation of the derivative contributes to the trigonal planar coordination of and displaces one of its three coordinated imidazole groups while a water molecule becomes hydrogen bonded to both the CN(-) ligand and the hydroxyl group of Tyr244. When O(2) is bound to Fe2+a3 , it is negatively polarized (O2- ), and expected to induce the same structural change induced by CN(-). This structural change allows to receive three electron equivalents nonsequentially from Cu1B+, Fe3+a3, and Tyr-OH, providing complete reduction of O(2) with minimization of production of active oxygen species. The proton-pumping pathway of bovine CcO comprises a hydrogen-bond network and a water channel which extend to the positive and negative side surfaces, respectively. Protons transferred through the water channel are pumped through the hydrogen-bond network electrostatically with positive charge created at the Fe(a) center by electron donation to the O(2) reduction site. Binding of CO or NO to induces significant narrowing of a section of the water channel near the hydrogen-bond network junction, which prevents access of water molecules to the network. In a similar manner, O(2) binding to is expected to prevent access of water molecules to the hydrogen-bond network. This blocks proton back-leak from the network and provides an efficient gate for proton-pumping.
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Affiliation(s)
- Kazumasa Muramoto
- Department of Life Science, University of Hyogo, 3-2-1 Kouto, Kamigohri, Akoh, Hyogo 678-1297, Japan; and
| | - Kazuhiro Ohta
- Institute for Protein Research, Osaka University, 3-2 Yamada-oka, Suita, Osaka 565-0871, Japan
| | - Kyoko Shinzawa-Itoh
- Department of Life Science, University of Hyogo, 3-2-1 Kouto, Kamigohri, Akoh, Hyogo 678-1297, Japan; and
| | - Katsumasa Kanda
- Department of Life Science, University of Hyogo, 3-2-1 Kouto, Kamigohri, Akoh, Hyogo 678-1297, Japan; and
| | - Maki Taniguchi
- Department of Life Science, University of Hyogo, 3-2-1 Kouto, Kamigohri, Akoh, Hyogo 678-1297, Japan; and
| | - Hiroyuki Nabekura
- Department of Life Science, University of Hyogo, 3-2-1 Kouto, Kamigohri, Akoh, Hyogo 678-1297, Japan; and
| | - Eiki Yamashita
- Institute for Protein Research, Osaka University, 3-2 Yamada-oka, Suita, Osaka 565-0871, Japan
| | - Tomitake Tsukihara
- Department of Life Science, University of Hyogo, 3-2-1 Kouto, Kamigohri, Akoh, Hyogo 678-1297, Japan; and
- Institute for Protein Research, Osaka University, 3-2 Yamada-oka, Suita, Osaka 565-0871, Japan
| | - Shinya Yoshikawa
- Department of Life Science, University of Hyogo, 3-2-1 Kouto, Kamigohri, Akoh, Hyogo 678-1297, Japan; and
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45
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Namslauer I, Lee HJ, Gennis RB, Brzezinski P. A pathogenic mutation in cytochrome c oxidase results in impaired proton pumping while retaining O(2)-reduction activity. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2010; 1797:550-6. [PMID: 20117076 DOI: 10.1016/j.bbabio.2010.01.027] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/22/2009] [Revised: 01/21/2010] [Accepted: 01/25/2010] [Indexed: 10/19/2022]
Abstract
In this work we have investigated the effect of a pathogenic mitochondrial DNA mutation found in human colon cells, at a functional-molecular level. The mutation results in the amino-acid substitution Tyr19His in subunit I of the human CytcO and it is associated with respiratory deficiency. It was introduced into Rhodobacter sphaeroides, which carries a cytochrome c oxidase (cytochrome aa(3)) that serves as a model of the mitochondrial counterpart. The residue is situated in the middle of a pathway that is used to transfer substrate protons as well as protons that are pumped across the membrane. The Tyr33His (equivalent residue in the bacterial CytcO) structural variant of the enzyme was purified and its function was investigated. The results show that in the structurally altered CytcO the activity decreased due to slowed proton transfer; proton transfer from an internal proton donor, the highly-conserved Glu286, to the catalytic site was slowed by a factor of approximately 5, while reprotonation of the Glu from solution was slowed by a factor of approximately 40. In addition, in the structural variant proton pumping was completely impaired. These results are explained in terms of introduction of a barrier for proton transfer through the D pathway and changes in the coordination of water molecules surrounding the Glu286 residue. The study offers an explanation, at the molecular level, to the link between a specific amino-acid substitution and a pathogenic phenotype identified in human colon cells.
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Affiliation(s)
- Ida Namslauer
- Department of Biochemistry and Biophysics, The Arrhenius Laboratories for Natural Sciences, Stockholm University, Stockholm, Sweden
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46
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Smirnov AY, Mourokh LG, Nori F. Kinetics of proton pumping in cytochrome c oxidase. J Chem Phys 2009; 130:235105. [DOI: 10.1063/1.3155213] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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47
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Lee-Young RS, Griffee SR, Lynes SE, Bracy DP, Ayala JE, McGuinness OP, Wasserman DH. Skeletal muscle AMP-activated protein kinase is essential for the metabolic response to exercise in vivo. J Biol Chem 2009; 284:23925-34. [PMID: 19525228 DOI: 10.1074/jbc.m109.021048] [Citation(s) in RCA: 114] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
AMP-activated protein kinase (AMPK) has been postulated as a super-metabolic regulator, thought to exert numerous effects on skeletal muscle function, metabolism, and enzymatic signaling. Despite these assertions, little is known regarding the direct role(s) of AMPK in vivo, and results obtained in vitro or in situ are conflicting. Using a chronically catheterized mouse model (carotid artery and jugular vein), we show that AMPK regulates skeletal muscle metabolism in vivo at several levels, with the result that a deficit in AMPK activity markedly impairs exercise tolerance. Compared with wild-type littermates at the same relative exercise capacity, vascular glucose delivery and skeletal muscle glucose uptake were impaired; skeletal muscle ATP degradation was accelerated, and arterial lactate concentrations were increased in mice expressing a kinase-dead AMPKalpha2 subunit (alpha2-KD) in skeletal muscle. Nitric-oxide synthase (NOS) activity was significantly impaired at rest and in response to exercise in alpha2-KD mice; expression of neuronal NOS (NOSmicro) was also reduced. Moreover, complex I and IV activities of the electron transport chain were impaired 32 +/- 8 and 50 +/- 7%, respectively, in skeletal muscle of alpha2-KD mice (p < 0.05 versus wild type), indicative of impaired mitochondrial function. Thus, AMPK regulates neuronal NOSmicro expression, NOS activity, and mitochondrial function in skeletal muscle. In addition, these results clarify the role of AMPK in the control of muscle glucose uptake during exercise. Collectively, these findings demonstrate that AMPK is central to substrate metabolism in vivo, which has important implications for exercise tolerance in health and certain disease states characterized by impaired AMPK activation in skeletal muscle.
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Affiliation(s)
- Robert S Lee-Young
- Department of Molecular Physiology and Biophysics, Vanderbilt University School of Medicine, Nashville, Tennessee 37232, USA.
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48
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Gao X, Zheng CY, Yang L, Tang XC, Zhang HY. Huperzine A protects isolated rat brain mitochondria against beta-amyloid peptide. Free Radic Biol Med 2009; 46:1454-62. [PMID: 19272446 DOI: 10.1016/j.freeradbiomed.2009.02.028] [Citation(s) in RCA: 75] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/26/2008] [Revised: 01/19/2009] [Accepted: 02/13/2009] [Indexed: 01/09/2023]
Abstract
Our previous work in cells and animals showed that mitochondria are involved in the neuroprotective effect of huperzine A (HupA). In this study, the effects of HupA on isolated rat brain mitochondria were investigated. In addition to inhibiting the Abeta(25-35) (40 microM)-induced decrease in mitochondrial respiration, adenosine 5'-triphosphate (ATP) synthesis, enzyme activity, and transmembrane potential, HupA (0.01 or 0.1 microM) effectively prevented Abeta-induced mitochondrial swelling, reactive oxygen species increase, and cytochrome c release. More interestingly, administration of HupA to isolated mitochondria promoted the rate of ATP production and blocked mitochondrial swelling caused by normal osmosis. These results indicate that HupA protects mitochondria against Abeta at least in part by preserving membrane integrity and improving energy metabolism. These direct effects on mitochondria further extend the noncholinergic functions of HupA.
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Affiliation(s)
- Xin Gao
- State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, 555 Zu Chong Zhi Road, Zhangjiang Hi-Tech Park, Shanghai 201203, People's Republic of China
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Kadenbach B, Ramzan R, Wen L, Vogt S. New extension of the Mitchell Theory for oxidative phosphorylation in mitochondria of living organisms. Biochim Biophys Acta Gen Subj 2009; 1800:205-12. [PMID: 19409964 DOI: 10.1016/j.bbagen.2009.04.019] [Citation(s) in RCA: 96] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2009] [Revised: 04/22/2009] [Accepted: 04/27/2009] [Indexed: 01/04/2023]
Abstract
The Mitchell Theory implies the proton motive force Deltap across the inner mitochondrial membrane as the energy-rich intermediate of oxidative phosphorylation. Deltap is composed mainly of an electrical (DeltaPsi(m)) and a chemical part (DeltapH) and generated by the respiratory chain complexes I, III and IV. It is consumed mostly by the ATP synthase (complex V) to produce ATP. The free energy of electron transport within the proton pumps is sufficient to generate Deltap of about 240 mV. The proton permeability of biological membranes, however, increases exponentially above 130 mV leading to a waste of energy at high values (DeltaPsi(m)>140 mV). In addition, at DeltaPsi(m)>140 mV, the production of the superoxide radical anion O(2)(-) at complexes I, II and III increases exponentially with increasing DeltaPsi(m). O(2)(-) and its neutral product H(2)O(2) (=ROS, reactive oxygen species) induce oxidative stress which participates in aging and in the generation of degenerative diseases. Here we describe a new mechanism which acts independently of the Mitchell Theory and keeps DeltaPsi(m) at low values through feedback inhibition of complex IV (cytochrome c oxidase) at high ATP/ADP ratios, thus preventing the formation of ROS and maintaining high efficiency of oxidative phosphorylation.
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Affiliation(s)
- Bernhard Kadenbach
- Fachbereich Chemie, Cardiovascular Laboratory, Philipps-University, D-35032 Marburg, Germany
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50
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Kadenbach B, Ramzan R, Vogt S. Degenerative diseases, oxidative stress and cytochrome c oxidase function. Trends Mol Med 2009; 15:139-47. [PMID: 19303362 DOI: 10.1016/j.molmed.2009.02.004] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2008] [Revised: 02/02/2009] [Accepted: 02/05/2009] [Indexed: 12/30/2022]
Abstract
Aging and degenerative diseases are associated with increased levels of reactive oxygen species (ROS). ROS are mostly produced in mitochondria, and their levels increase with higher mitochondrial membrane potential. Cellular respiratory control is based on inhibition of respiration by high membrane potentials. However, we have described a second mechanism of respiratory control based on allosteric inhibition of cytochrome c oxidase (CcO), the terminal enzyme of the respiratory chain, at high ATP:ADP ratios. The mechanism is independent of membrane potential. We have proposed that feedback inhibition of CcO by ATP keeps the membrane potential and ROS production at low levels. Various forms of stress switch off allosteric ATP-inhibition via reversible dephosphorylation of CcO, resulting in increased membrane potential and cellular ROS levels. This mechanism is proposed to represent a missing molecular link between stress and degenerative diseases.
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