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Updated: Jan 23, 2026

Purification of Active Photosystem I-Light Harvesting Complex I from Plant Tissues
Published on: February 3, 2023
pH-Responsive Binding Properties of Light-Harvesting Complexes in a Photosystem II Supercomplex Investigated by
Eunchul Kim1, Akimasa Watanabe1,2, Ryoichi Sato1
1Division of Environmental Photobiology , National Institute for Basic Biology , Okazaki 444-8585 , Japan.
Abstract:
Reorganization of photosynthetic proteins on the thylakoid membrane is an important regulatory process for photoacclimation in photosynthetic organisms. However, the underlying mechanism has been poorly understood due to the lack of methods to analyze the interactions between membrane proteins. To investigate the mechanism, we demonstrated the binding properties of light-harvesting complex proteins (LHCs) in a photosystem II (PSII) supercomplex regulated by pH conditions, which primarily responded to environmental light conditions, using a thermodynamic dissociation kinetics analysis. The results showed that the strongly bound LHCs (∼60%) were responsive to pH conditions, whereas the moderately and loosely bound LHCs (∼40%) were nonresponsive. This result implies that the pH condition alters the binding properties of LHCs in the PSII supercomplex, inducing the reorganization of protein complexes.
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