EPR Study of the Oxidation States and the Metalloradical Intermediate States of the Oxygen Evolving Complex of Photosystem II
Event details
| Date | 26.10.2011 |
| Hour | 16:15 |
| Speaker | Dr. Georgia Zahariou, Institute of Materials Science, NCSR “Demokritos”, Greece |
| Location |
PH L1 503
|
| Category | Conferences - Seminars |
The light-driven water splitting to molecular oxygen is catalyzed by a membrane-protein complex known as Photosystem II. In natural spinach Photosystem II, the catalytic site of water oxidation, called Oxygen Evolving Complex (OEC), contains a tetranuclear Mn cluster (Mn4). During the absorption of four photons by Photosystem II, the Mn4 undergoes periodically four oxidation steps: S0 → S1, S1 → S2, S2 → S3 and S3 → (S4)S0. The intermediates of the S-state transitions involve the free radical of Tyrosine Z (TyrZ•), which interacts magnetically with Mn cluster. Tyrosine Z (TyrZ) of Photosystem II is in close proximity with Mn cluster and it is thought to play a critical role in the proton-coupled electron transfer reactions of water to molecular oxygen. The ground spin-state of the S3 state, as well as the interaction between TyrZ• and Mn cluster (metallo-radical mechanism) to the water oxidation process is under investigation.
Practical information
- Informed public
- Free
Organizer
- ICMP
Contact
- Prof. László Forró, Dr. Andrzej Sienkiewicz