Revealing The Linear Aggregates Of Light Harvesting Antenna Proteins In Photosynthetic Membranes

Abstract

How light energy is harvested in a natural photosynthetic membrane through energy transfer is closely related to the stoichiometry and arrangement of light harvesting antenna proteins in the membrane. Their specific architecture helps them to absorb photons in the primary process of photosynthesis that is subsequently followed by a rapid and efficient energy transfer among the light harvesting proteins (LH2 and LH1) and to the reaction center. In this work, using atomic force microscopy (AFM) imaging, single membrane fragment FRET spectroscopy, spectral fluctuation analysis, and time-resolved spectroscopic analysis, we show the identification of linear aggregates of light harvesting proteins, LH2, in the photosynthetic membranes under ambient conditions. Our results suggest that the light harvesting proteins, LH2, mostly exist in two states, the aggregated and non-aggregated states in the photosynthetic membranes. Our results shed a light on understanding the complex intramolecular energy transfer dynamics and mechanism of the light harvesting in the photosynthetic membranes.