Dhingra 2015 Cell Death Dis
From Bioblast
| Dhingra R, Kirshenbaum LA (2015) Succinate dehydrogenase/complex II activity obligatorily links mitochondrial reserve respiratory capacity to cell survival in cardiac myocytes. Cell Death Dis 6:e1956. https://doi.org/10.1038/cddis.2015.310 |
Dhingra R, Kirshenbaum LA (2015) Cell Death Dis
Abstract: The concept that cells die by a genetically regulated process has profound implications for human diseases in which too little or too much cell death is the primary etiology of the disease. In the context of the adult myocardium, which exhibits a limited capacity for de novo myocyte regeneration after injury, the functional loss of cardiac cells by de-regulated programmed apoptosis or necrosis is postulated as the central cause of ventricular remodeling and heart failure following myocardial infarction.
• Bioblast editor: Gnaiger E
Hydrogen ion ambiguities in the electron transfer system
Communicated by Gnaiger E (2023-10-08) last update 2023-11-10
- Electron (e-) transfer linked to hydrogen ion (hydron; H+) transfer is a fundamental concept in the field of bioenergetics, critical for understanding redox-coupled energy transformations.
- However, the current literature contains inconsistencies regarding H+ formation on the negative side of bioenergetic membranes, such as the matrix side of the mitochondrial inner membrane, when NADH is oxidized during oxidative phosphorylation (OXPHOS). Ambiguities arise when examining the oxidation of NADH by respiratory Complex I or succinate by Complex II.
- Oxidation of NADH or succinate involves a two-electron transfer of 2{H++e-} to FMN or FAD, respectively. Figures indicating a single electron e- transferred from NADH or succinate lack accuracy.
- The oxidized NAD+ is distinguished from NAD indicating nicotinamide adenine dinucleotide independent of oxidation state.
- NADH + H+ → NAD+ +2{H++e-} is the oxidation half-reaction in this H+-linked electron transfer represented as 2{H++e-} (Gnaiger 2023). Putative H+ formation shown as NADH → NAD+ + H+ conflicts with chemiosmotic coupling stoichiometries between H+ translocation across the coupling membrane and electron transfer to oxygen. Ensuring clarity in this complex field is imperative to tackle the apparent ambiguity crisis and prevent confusion, particularly in light of the increasing number of interdisciplinary publications on bioenergetics concerning diagnostic and clinical applications of OXPHOS analysis.
