scholarly journals Impact of Hydrogen Sulfide on Mitochondrial and Bacterial Bioenergetics

2021 ◽  
Vol 22 (23) ◽  
pp. 12688
Author(s):  
Vitaliy B. Borisov ◽  
Elena Forte
Keyword(s):  
Hydrogen Sulfide ◽  
Electron Transport ◽  
Respiratory Chain ◽  
Protein Complexes ◽  
Biological Effects ◽  
Mitochondrial Respiratory Chain ◽  
Quinone Oxidoreductase ◽  
Ongoing Research ◽  
Atp Production ◽  
The Impact

This review focuses on the effects of hydrogen sulfide (H2S) on the unique bioenergetic molecular machines in mitochondria and bacteria—the protein complexes of electron transport chains and associated enzymes. H2S, along with nitric oxide and carbon monoxide, belongs to the class of endogenous gaseous signaling molecules. This compound plays critical roles in physiology and pathophysiology. Enzymes implicated in H2S metabolism and physiological actions are promising targets for novel pharmaceutical agents. The biological effects of H2S are biphasic, changing from cytoprotection to cytotoxicity through increasing the compound concentration. In mammals, H2S enhances the activity of FoF1-ATP (adenosine triphosphate) synthase and lactate dehydrogenase via their S-sulfhydration, thereby stimulating mitochondrial electron transport. H2S serves as an electron donor for the mitochondrial respiratory chain via sulfide quinone oxidoreductase and cytochrome c oxidase at low H2S levels. The latter enzyme is inhibited by high H2S concentrations, resulting in the reversible inhibition of electron transport and ATP production in mitochondria. In the branched respiratory chain of Escherichia coli, H2S inhibits the bo3 terminal oxidase but does not affect the alternative bd-type oxidases. Thus, in E. coli and presumably other bacteria, cytochrome bd permits respiration and cell growth in H2S-rich environments. A complete picture of the impact of H2S on bioenergetics is lacking, but this field is fast-moving, and active ongoing research on this topic will likely shed light on additional, yet unknown biological effects.

Regulation of mitochondrial respiration in eggs and embryos of sea urchin

Zygote ◽  
1999 ◽  
Vol 8 (S1) ◽  
pp. S3-S4
Author(s):  
Ikuo Yasumasu
Keyword(s):  
Electron Transport ◽  
Respiratory Rate ◽  
Respiratory Chain ◽  
Sea Urchin ◽  
Mitochondrial Respiration ◽  
Atp Release ◽  
Mitochondrial Respiratory Chain ◽  
High Concentration ◽  
Respiratory Systems ◽  
Mitochondrial Respiratory

It is well known that sea urchin eggs, which exhibit quite a low rate of respiration before fertilisation, undergo a sudden increase in the rate of respiration followed by its gradual decrease in about a 15 min period after fertilisation (Ohnishi & Sugiyama, 1963; Epel, 1969), in which the respiration is mediated mainly by Ca2+-activated non-mitochondrial respiratory systems (Foerder et al., 1978; Perry & Epel, 1985a,b). During this short period the rate of mitochondrial respiration gradually increases (Yasumasu et al., 1988) and stabilises at a higher rate than before fertilisation (Warburg, 1908, 1910; Whitaker, 1933; Yasumasu & Nakano, 1963), when the respiration due to non-mitochondrial respiratory systems is turned off. The rate of mitochondrial respiration, once enhanced upon fertilisation, increases further in the period between hatching and the gastrula stage, without any changes in the number of mitochondria or the capacity of electron transport in the mitochondrial respiratory chain (Fujiwara & Yasumasu, 1997; Fujiwara et al., 2000). It is likely that the respiratory rate is reduced by regulation of electron transport in the mitochondrial respiratory chain and increases due to the release of electron transport from the regulation upon fertilisation and after hatching.A marked increase in the respiratory rate after hatching is accompanied by an evident decrease in the ATP level without any change in the levels of ADP and AMP (Mita & Yasumasu, 1984). In isolated mitochondria, the rate of respiration, estimated in the presence of ADP at the same concentration as in embryos, is reduced by a high concentration of ATP as found in embryos before hatching but is not affected at a concentration as low as in gastrulae (Fujiwara & Yasumasu, 1997; Fujiwara et al., 2000) ATP at a high concentration probably blocks ATP release from mitochondria and consequently inhibits ADP uptake coupled to ATP release in the ATP/ADP translocation reaction in the mitochondrial membrane, causing a shortage of intra-mitochondrial ADP.

scholarly journals Five decades of research on mitochondrial NADH-quinone oxidoreductase (complex I)

2018 ◽  
Vol 399 (11) ◽  
pp. 1249-1264 ◽  
Author(s):  
Tomoko Ohnishi ◽  
S. Tsuyoshi Ohnishi ◽  
John C. Salerno
Keyword(s):  
Electron Transfer ◽  
Respiratory Chain ◽  
Complex I ◽  
Proton Translocation ◽  
Atp Synthesis ◽  
Mitochondrial Respiratory Chain ◽  
Proton Pumping ◽  
Entry Site ◽  
Quinone Oxidoreductase ◽  
Terminal Electron Acceptor

AbstractNADH-quinone oxidoreductase (complex I) is the largest and most complicated enzyme complex of the mitochondrial respiratory chain. It is the entry site into the respiratory chain for most of the reducing equivalents generated during metabolism, coupling electron transfer from NADH to quinone to proton translocation, which in turn drives ATP synthesis. Dysfunction of complex I is associated with neurodegenerative diseases such as Parkinson’s and Alzheimer’s, and it is proposed to be involved in aging. Complex I has one non-covalently bound FMN, eight to 10 iron-sulfur clusters, and protein-associated quinone molecules as electron transport components. Electron paramagnetic resonance (EPR) has previously been the most informative technique, especially in membranein situanalysis. The structure of complex 1 has now been resolved from a number of species, but the mechanisms by which electron transfer is coupled to transmembrane proton pumping remains unresolved. Ubiquinone-10, the terminal electron acceptor of complex I, is detectable by EPR in its one electron reduced, semiquinone (SQ) state. In the aerobic steady state of respiration the semi-ubiquinone anion has been observed and studied in detail. Two distinct protein-associated fast and slow relaxing, SQ signals have been resolved which were designated SQNfand SQNs. This review covers a five decade personal journey through the field leading to a focus on the unresolved questions of the role of the SQ radicals and their possible part in proton pumping.

scholarly journals The road to the structure of the mitochondrial respiratory chain supercomplex

2020 ◽  
Vol 48 (2) ◽  
pp. 621-629
Author(s):  
Nikeisha J. Caruana ◽  
David A. Stroud
Keyword(s):  
Respiratory Chain ◽  
Large Body ◽  
Mitochondrial Respiratory Chain ◽  
Proton Pumping ◽  
Atp Production ◽  
Structural Characterisation ◽  
The Road ◽  
X Ray Crystallography ◽  
History Of ◽  
Mitochondrial Respiratory

The four complexes of the mitochondrial respiratory chain are critical for ATP production in most eukaryotic cells. Structural characterisation of these complexes has been critical for understanding the mechanisms underpinning their function. The three proton-pumping complexes, Complexes I, III and IV associate to form stable supercomplexes or respirasomes, the most abundant form containing 80 subunits in mammals. Multiple functions have been proposed for the supercomplexes, including enhancing the diffusion of electron carriers, providing stability for the complexes and protection against reactive oxygen species. Although high-resolution structures for Complexes III and IV were determined by X-ray crystallography in the 1990s, the size of Complex I and the supercomplexes necessitated advances in sample preparation and the development of cryo-electron microscopy techniques. We now enjoy structures for these beautiful complexes isolated from multiple organisms and in multiple states and together they provide important insights into respiratory chain function and the role of the supercomplex. While we as non-structural biologists use these structures for interpreting our own functional data, we need to remind ourselves that they stand on the shoulders of a large body of previous structural studies, many of which are still appropriate for use in understanding our results. In this mini-review, we discuss the history of respiratory chain structural biology studies leading to the structures of the mammalian supercomplexes and beyond.

Coenzyme Q: potentially useful index of bioenergetic and oxidative status of spermatozoa

1995 ◽  
Vol 41 (2) ◽  
pp. 217-219 ◽  
Author(s):  
A G Angelitti ◽  
L Colacicco ◽  
C Callà ◽  
M Arizzi ◽  
S Lippa
Keyword(s):  
Respiratory Chain ◽  
Coenzyme Q10 ◽  
Coenzyme Q ◽  
Mitochondrial Respiratory Chain ◽  
Oxidative Status ◽  
Atp Production ◽  
The Difference ◽  
Autoregulatory Mechanism ◽  
Infertile Patients ◽  
Mitochondrial Respiratory

Abstract The concentration of coenzyme Q10 (CoQ10), a key intermediate of the mitochondrial respiratory chain, was determined in spermatozoa of 13 fertile subjects, 8 potentially fertile patients, and 12 infertile patients. CoQ10 concentrations were significantly higher (P < 0.001) in infertile patients than in fertile and potentially fertile subjects. The difference between potentially fertile and fertile subjects was also significant (P < 0.001). We propose that a decrease in consumption of CoQ10 in both infertile and potentially fertile populations is due to an autoregulatory mechanism of ATP production.

scholarly journals Sites of inhibition of mitochondrial electron transport in macrophage-injured neoplastic cells.

1982 ◽  
Vol 95 (2) ◽  
pp. 527-535 ◽  
Author(s):  
D L Granger ◽  
A L Lehninger
Keyword(s):  
Electron Transport ◽  
Respiratory Chain ◽  
Mitochondrial Respiration ◽  
Intact Cell ◽  
Coenzyme Q ◽  
Mitochondrial Respiratory Chain ◽  
Neoplastic Cells ◽  
L1210 Cells ◽  
Time Courses ◽  
A Minor

Previous work has shown that injury of neoplastic cells by cytotoxic macrophages (CM) in cell culture is accompanied by inhibition of mitochondrial respiration. We have investigated the nature of this inhibition by studying mitochondrial respiration in CM-injured leukemia L1210 cells permeabilized with digitonin. CM-induced injury affects the mitochondrial respiratory chain proper. Complex I (NADH-coenzyme Q reductase) and complex II (succinate-coenzyme Q reductase) are markedly inhibited. In addition a minor inhibition of cytochrome oxidase was found. Electron transport from alpha-glycerophosphate through the respiratory chain to oxygen is unaffected and permeabilized CM-injured L1210 cells oxidizing this substrate exhibit acceptor control. However, glycerophosphate shuttle activity was found not to occur within CM-injured or uninjured L1210 cells in culture hence, alpha-glycerophosphate is apparently unavailable for mitochondrial oxidation in the intact cell. It is concluded that the failure of respiration of intact neoplastic cells injured by CM is caused by the nearly complete inhibition of complexes I and II of the mitochondrial electron transport chain. The time courses of CM-induced electron transport inhibition and arrest of L1210 cell division are examined and the possible relationship between these phenomena is discussed.

scholarly journals The mitochondrial respiratory chain is a modulator of apoptosis

2007 ◽  
Vol 179 (6) ◽  
pp. 1163-1177 ◽  
Author(s):  
Jennifer Q. Kwong ◽  
Matthew S. Henning ◽  
Anatoly A. Starkov ◽  
Giovanni Manfredi
Keyword(s):  
Er Stress ◽  
Respiratory Chain ◽  
Electron Flux ◽  
Atp Synthesis ◽  
Mitochondrial Respiratory Chain ◽  
Dependent Manner ◽  
Atp Production ◽  
Dna Mutations ◽  
Increased Sensitivity ◽  
Induced Apoptosis

Mitochondrial dysfunction and dysregulation of apoptosis are implicated in many diseases such as cancer and neurodegeneration. We investigate here the role of respiratory chain (RC) dysfunction in apoptosis, using mitochondrial DNA mutations as genetic models. Although some mutations eliminate the entire RC, others target specific complexes, resulting in either decreased or complete loss of electron flux, which leads to impaired respiration and adenosine triphosphate (ATP) synthesis. Despite these similarities, significant differences in responses to apoptotic stimuli emerge. Cells lacking RC are protected against both mitochondrial- and endoplasmic reticulum (ER) stress–induced apoptosis. Cells with RC, but unable to generate electron flux, are protected against mitochondrial apoptosis, although they have increased sensitivity to ER stress. Finally, cells with a partial reduction in electron flux have increased apoptosis under both conditions. Our results show that the RC modulates apoptosis in a context-dependent manner independent of ATP production and that apoptotic responses are the result of the interplay between mitochondrial functional state and environmental cues.

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