• CP29
• light-harvesting complex
• photoprotection
• non-photochemical quenching
• NPQ
• pigments
• pigment-protein complex
• computational analysis
• molecular dynamics

The aim of the present work is to analyse the structure and the response to light of the pigment - protein complex CP29, a light harvesting (LH) component located in the the inner layer of photosystem II (PSII) super-complex of higher plants. It is well known that the structural and functional state of CP29 (like other LH complexes) depends on the light conditions, reflecting the need to rapidly adapt to changeable light exposure. In fact, in excess light conditions, which could damage the PSII components, a set of photoprotective mechanisms are activated, in order to dissipate most of the energy absorbed by the embedded chlorophyll pigments as heat. These dissipative processes are referred to as non-photochemical quenching (NPQ) and require a change in the interactions among the chlorophylls and the ancillary pigments, different types of carotenoids.
Our project built upon the recent work of Guardini et al. (Nature Plants, 2020
https://doi.org/10.1038/s41477-020-0612-8 ): the authors generated several CP29 mutants, and measured their spectroscopic and quenching properties. Our purpose is to perform a computational analysis based on Molecular Dynamics (MD) simulations of CP29-WT and one of the above mentioned mutants, CP29-H111N, in order to identify differences in their structures and hopefully to connect them with the differences experimentally observed in the quenching behaviour of the two complexes.