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Updated: Feb 13, 2026
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Synthesis and Evaluation of a Ruthenium-based Mitochondrial Calcium Uptake Inhibitor
Published on: October 26, 2017
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RUTHENIUM RED INHIBITION OF OXYGEN EVOLUTION AND SPECIFIC RELEASE OF THE EXTRINSIC 16 kDa POLYPEPTIDE IN A
Paul Jursinic1, Nathalie Miller2, Robert Carpentier2
1Northern Regional Research Center, Agricultural Research Service, U.S. Department of Agriculture, Peoria, IL 61604, USA.
Photochemistry and Photobiology
|March 3, 2018
Summary
Ruthenium red inhibits photosystem II by quenching chlorophyll fluorescence and reducing oxygen evolution. It also blocks charge transfer and releases a key polypeptide, suggesting it disrupts the water-splitting complex.
Area of Science:
- Biochemistry
- Photosynthesis research
- Plant physiology
Background:
- Photosystem II (PSII) is crucial for oxygenic photosynthesis.
- Understanding PSII inhibition mechanisms is vital for photosynthesis research.
Purpose of the Study:
- To investigate the inhibitory effects of ruthenium red on photosystem II.
- To elucidate the molecular mechanisms underlying ruthenium red's action on PSII.
Main Methods:
- Studied photosystem II-enriched submembrane fractions.
- Measured chlorophyll fluorescence (F0, Fm) and oxygen evolution rates.
- Assessed effects of varying ruthenium red concentrations and incubation times.
- Monitored charge transfer reactions and polypeptide release.
Main Results:
- Ruthenium red instantaneously quenched chlorophyll fluorescence and decreased oxygen evolution quantum yield.
- Inhibition of oxygen evolution and variable fluorescence increased with incubation time.
- Ruthenium red blocked the Z P680+ → Z+ P680 charge transfer reaction after 5 min incubation.
- The dye induced release of the 16 kDa extrinsic polypeptide without Mn release.
Conclusions:
- Ruthenium red exhibits multiple inhibitory interactions with photosystem II.
- The dye's action is more complex than simple Ca2+ or Cl- depletion.
- Ruthenium red likely causes an ionic imbalance, altering the PSII donor side configuration and affecting water-splitting.
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