Light4Switch: Conformational Switch of Light-Harvesting Complexes Upon Illuminating Azobenzene

Plants can dissipate excess absorbed light energy as heat, by reversible switching of light-harvesting complex II (LHCII) into photoprotected quenched states, to prevent photodamage of photosynthetic apparatus.

The conformational switch of LHCII is suggested to modulate the interaction between the embedded pigments, and consequently activate charge transfer and/or excitation energy transfer processes which ultimately lead to the dissipation of excess energy as heat, known as energy-dependent quenching (qE).

Although the site of qE has been long established, i.e. the LHCII, the specific protein domains and conformational switches responsible for activating qE are currently unknown.This MSCA fellowship project AZO-LHCII aims to determine the role of the protein matrix of the LHCII in tuning their energetic state and driving the photoprotective switch of plants.

To this end, this disciplinary project will for the first time strive to manipulate the conformation of LHCII antenna proteins with azobenzene photoswitches and use a novel multipulse transient absorption spectroscopy approach to study in real-time the effect of site-specific conformational fluctuations on the regulation of the excitation energy transfer in LHCII.