Connecting dots between natural and artificial photosynthesis : magnetic resonance studies on light harvesting and the water oxidation reaction centre

Sunku, K. (2019)

Doctoral Thesis

Decentralized plug and play systems for energy production are the future picture of our society. Artificial photosynthetic systems are used for this purpose. These systems are inspired by natural photosynthesis.
Chapter 2 illustrates the detailed construction of a three-flash flow cell to study light induced biological reactions, specifically the water oxidation reaction of Photosystem II. This instrument is capable of producing the S2+, S3+ and S0n intermediate states of the Kok cycle. I confirmed these by EPR experiments.
In chapter 3, I study the mechanism of the major LHC II involved in conformational switching from light harvesting to the photoprotective state, in which excess light is dissipated as heat. I use MAS NMR as a non-invasive method to understand the structure and environment around Arg residues in Chlamydomonas reinhardtii LHC II. In this approach the Arg amino acid is selectively labeled with 13C isotopes
Chapter 4 studies the structure of self-aggregated semi synthetic Zn 31 amino chlorin that forms syn-anti parallel stacks according to the solid state NMR data. The small change of removing 33 methyl group of Zn 31 aminomethyl chlorin has significant effect on self-assembly. Finally, chapter 5 provides an outlook on future research.

• Photosynthesis
• NPQ
• Solid state NMR
• EPR
• Three flash flow cell

• All authors: Sunku, K.
• Supervisor: Groot, H.J.M. de
• Co-supervisor: Pandit, A.
• Committee: Overkleeft, H.S.; Ubbink, M.; Kargul, J.; Holzwarth, A.
• Qualification: Doctor (dr.)
• Awarding Institution: Leiden Institute of Chemistry (LIC), Faculty of Science, Leiden University
• Date: 2019-12-13
• ISBN (print): 9789492597366