© 2015 by The American Society for Biochemistry and Molecular Biology, Inc. Styrene-maleic acid copolymer was used to effect a non-detergent partial solubilization of thylakoids from spinach. A high density membrane fraction, which was not solubilized by the copolymer, was isolated and was highly enriched in the Photosystem (PS) I-light-harvesting chlorophyll (LHC) II supercomplex and depleted of PS II, the cytochrome b6/f complex, and ATP synthase. The LHC II associated with the supercomplex appeared to be energetically coupled to PS I based on 77 K fluorescence, P700 photooxidation, and PS I electron transport light saturation experiments. The chlorophyll (Chl) a/b ratio of the PS I-LHC II membranes was 3.2 ± 0.9, indicating that on average, three LHC II trimers may associate with each PS I. The implication of these findings within the context of higher plant PS I antenna organization is discussed.
Publication Source (Journal or Book title)
Journal of Biological Chemistry
Bell, A., Frankel, L., & Bricker, T. (2015). High yield non-detergent isolation of photosystem I-light-harvesting chlorophyll II membranes from spinach thylakoids: Implications for the organization of the PS I antennae in higher plants. Journal of Biological Chemistry, 290 (30), 18429-18437. https://doi.org/10.1074/jbc.M115.663872