6 research outputs found
Influence of the Carotenoid Composition on the Conformational Dynamics of Photosynthetic Light-Harvesting Complexes
Nonphotochemical
quenching (NPQ) is the major self-regulatory mechanism
of green plants, performed on a molecular level to protect them from
an overexcitation during the direct sunlight. It is believed that
NPQ becomes available due to conformational dynamics of the light-harvesting
photosynthetic complexes and involves a direct participation of carotenoids.
In this work, we perform a single-molecule microscopy on major light-harvesting
complexes (LHCII) from different Arabidopsis thaliana mutants exhibiting various carotenoid composition. We show how the
distinct carotenoids affect the dynamics of the conformational switching
between multiple coexisting light-emitting states of LHCII and demonstrate
that properties of the quenched conformation are not influenced by
the particular carotenoids available in LHCII. We also discuss the
possible origin of different conformational states and relate them
to the fluorescence decay kinetics observed during the bulk measurements