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 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.

scholarly journals Kinetics of integrated electron transfer in the mitochondrial respiratory chain: random collisions vs. solid state electron channeling

2007 ◽  
Vol 292 (4) ◽  
pp. C1221-C1239 ◽  
Author(s):  
Giorgio Lenaz ◽  
Maria Luisa Genova
Keyword(s):  
Respiratory Chain ◽  
Coenzyme Q ◽  
Lateral Diffusion ◽  
Kinetic Studies ◽  
Mitochondrial Respiratory Chain ◽  
Substrate Channeling ◽  
Solid State Electron ◽  
Native Electrophoresis ◽  
Redox Molecules ◽  
Mitochondrial Respiratory

Recent evidence, mainly based on native electrophoresis, has suggested that the mitochondrial respiratory chain is organized in the form of supercomplexes, due to the aggregation of the main respiratory chain enzymatic complexes. This evidence strongly contrasts the previously accepted model, the Random Diffusion Model, largely based on kinetic studies, stating that the complexes are randomly distributed in the lipid bilayer of the inner membrane and functionally connected by lateral diffusion of small redox molecules, i.e., coenzyme Q and cytochrome c. This review critically examines the experimental evidence, both structural and functional, pertaining to the two models and attempts to provide an updated view of the organization of the respiratory chain and of its kinetic consequences. The conclusion that structural respiratory assemblies exist is overwhelming, whereas the expected functional consequence of substrate channeling between the assembled enzymes is controversial. Examination of the available evidence suggests that, although the supercomplexes are structurally stable, their kinetic competence in substrate channeling is more labile and may depend on the system under investigation and the assay conditions.

scholarly journals Vitamin K2 cannot substitute Coenzyme Q10 as electron carrier in the mitochondrial respiratory chain of mammalian cells

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Cristina Cerqua ◽  
Alberto Casarin ◽  
Fabien Pierrel ◽  
Luis Vazquez Fonseca ◽  
Giampiero Viola ◽  
...  
Keyword(s):  
Respiratory Chain ◽  
Coenzyme Q10 ◽  
Mammalian Cells ◽  
Mitochondrial Respiratory Chain ◽  
Vitamin K2 ◽  
Electron Carrier ◽  
Mitochondrial Respiratory
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