Five decades of research on mitochondrial NADH-quinone oxidoreductase (complex I).
Level 5 - mechanism / opinion, no new human data
Narrative review of basic biochemical mechanisms without human clinical data.
PubMed 30243012 · doi:10.1515/hsz-2018-0164
What was done
This is a narrative review covering five decades of basic biochemical and biophysical research on mitochondrial NADH-quinone oxidoreductase (complex I). The author reviews structural biology insights and electron paramagnetic resonance (EPR) spectroscopy data on redox components, particularly focusing on iron-sulfur clusters and ubiquinone-10 semiquinone (SQ) intermediates.
What was found
The abstract reports no quantitative clinical or statistical metrics. It describes complex I as containing one non-covalently bound FMN, eight to 10 iron-sulfur clusters, and protein-associated quinone molecules. During aerobic steady-state respiration, EPR spectroscopy identifies two distinct protein-associated semiquinone signals (designated fast-relaxing SQNf and slow-relaxing SQNs). The exact mechanism coupling electron transfer to transmembrane proton pumping remains unresolved.
Why it matters
Understanding the electron transfer and proton pumping mechanisms of complex I is fundamental to mitochondrial bioenergetics and informs research into conditions linked to complex I dysfunction, including Parkinson's disease, Alzheimer's disease, and aging.
Limits
The paper is a non-systematic narrative review of basic biochemistry rather than an empirical trial or systematic review. No clinical populations, sample sizes, or quantitative outcome measures are reported in the abstract.
Cited by
- supports Mitochondria contain iron-sulfur clusters that are paramagnetic and can physically interact with magnetic fields.