Mechanism of superoxide and hydrogen peroxide generation by human electron-transfer flavoprotein and pathological variants

► Reactive oxygen species production by fatty acid β-oxidation is poorly characterized. ► Human electron-transfer flavoprotein produces both superoxide and hydrogen peroxide. ► Superoxide generation is dependent on the concentration of its partner dehydrogenase. ► Protein:protein interactions modulate the production of reactive oxygen species. ► Disease mutants show higher production of reactive oxygen species.