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Updated: Sep 7, 2025

Isolating and Incorporating Light-Harvesting Antennas from Diatom Cyclotella Meneghiniana in Liposomes with Thylakoid Lipids
Published on: August 28, 2018
The Structural and Spectral Features of Light-Harvesting Complex II Proteoliposomes Mimic Those of Native Thylakoid
Sam Wilson1, Dan-Hong Li1, Alexander V Ruban1
1Department of Biochemistry, School of Biological and Behavioural Sciences, Queen Mary University of London, Mile End Road, London E1 4NS, United Kingdom.
Abstract:
The major photosystem II light-harvesting antenna (LHCII) is the most abundant membrane protein in nature and plays an indispensable role in light harvesting and photoprotection in the plant thylakoid. Here, we show that "pseudothylakoid characteristics" can be observed in artificial LHCII membranes. In our proteoliposomal system, at high LHCII densities, the liposomes become stacked, mimicking the in vivo thylakoid grana membranes. Furthermore, an unexpected, unstructured emission peak at ∼730 nm appears, similar in appearance to photosystem I emission, but with a clear excimeric character that has never been previously reported. These states correlate with the increasing density of LHCII in the membrane and a decrease in its average fluorescence lifetime. The appearance of these low-energy states can also occur in natural plant membrane structures, which has unique consequences for the interpretation of the spectroscopic and physiological properties of the photosynthetic membrane.
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