Oxygen drives a rapid, reversible photoprotective switch in photosynthetic antennae

Oxygen drives a rapid, reversible photoprotective switch in photosynthetic light-harvesting complexes, forming a protein-stabilized charge-separated state with oxidized chlorophyll and superoxide.

• Why it matters: Oxygen is linked to photooxidative damage, yet how it can also trigger fast, reversible protection in antenna complexes is unclear.
• What they did: The study used a new bulk fluorescence assay to distinguish reversible dark states from irreversible photobleaching, plus single-molecule spectroscopy, in photosynthetic light-harvesting complexes.
• The result: Illumination plus oxygen generates the reversible charge-separated state, which increasingly outcompetes irreversible photodamage at physiological excitation intensities and is strongly accelerated by ascorbic acid in native thylakoid membranes.

AI summary of the abstract · may contain errors · not medical advice · read the paper.