From proteins to the thylakoid membrane
This project consists of two subprojects:
1. Non-linear microscopy of the thylakoid membrane, and
2. Modeling the dynamics of excitation in oxygenic photosynthesis
The team that will carry out this project is composed of staff members of the Department of Biophysics, Division of Physics and Astronomy, Faculty of Sciences, Vrije Universiteit.
Non-linear microscopy of the thylakoid membrane
This project entails:
1. The construction of a high resolution (~20 nm) fluorescence microscope using stimulated emission depletion (STED) and/or multipulse excitation, adapted to the specific needs and possibilities of photosynthetic membrane;
2. Making a functional image of the photosynthetic membranes with this microscope, and
34. Building a (preliminary) theoretical framework to describe the relation between membrane structure and organization and its light-harvesting function (based on molecular models that have been developed for the individual complexes and on structural/organization models of the thylakoid membrane obtained with electron microscopy).
Modeling the dynamics of excitation in oxygenic photosynthesis
This part of the project aims:
1. To extend the energy transfer model (disordered exciton/Redfield relaxation) that has been developed for trimers of LHCII, the PSII RC and for the core of PS1 to (a) understand energy transfer and trapping in the Photosystem II supercomplex and (b) in the thylakoid membrane. The modelling will be based on experimental excited state dynamics studies of the components, on an explicit model for the structural organization of the thylakoid membrane and on experimentally established energy transfer pathways;
2. To explicitly include a switching mechanism allowing the antenna of Photosystem 2 to make a fast transition from a dark to a light state. The model will explicitly include experimentally determined switching properties of LHCII, and
3. To include feedback regulation into the model. For this purpose a course-grained model of energy transfer and charge separation in the thylakoid membrane will be developed, that on the one hand connects to the model developed in objectives (1) and (2) and at the same time allows to describe the dynamics over a timescale of seconds.