title: Fragmentation and separation analysis of the photosynthetic membrane from spinach.
abstract: Membrane vesicles, originating from grana, grana core (appressed grana regions), grana margins and stroma lamellae/end membranes, were analysed by counter current distribution (CCD) using aqueous dextran-polyethylene glycol two-phase systems. Each vesicle population gave rise to distinct peaks in the CCD diagram representing different vesicle subpopulations. The grana vesicles and grana core vesicles each separated into 3 different subpopulations having different chlorophyll a/b ratios and PSI/PSII ratios. Two of the grana core subpopulations had a chlorophyll a/b ratio of 2.0 and PSI/PSII ratio of 0.10 and are among the most PSII enriched thylakoid vesicle preparation obtained so far by a non detergent method. The margin vesicles separated into 3 different populations, with about the same chlorophyll a/b ratios, but different fluorescence emission spectra. The stroma lamellae/end membrane vesicles separated into 4 subpopulations. Plastoglobules, connected to membrane vesicles, were highly enriched in 2 of these subpopulations and it is proposed that these 2 subpopulations originate from stroma lamellae while the 2 others originate from end membranes. Fragmentation and separation analysis shows that the margins of grana constitute a distinct domain of the thylakoid and also allows the estimation of the chlorophyll antenna sizes of PSI and PSII in different thylakoid domains.
authors.affiliation: Department of Biochemistry, Chemical Centre, Lund University, P.O. Box 124, S-221 00 Lund, Sweden.
authors.forename: Ravi
authors.initials: R
authors.lastname: Danielsson
authors.forename: Per-Ake
authors.initials: PA
authors.lastname: Albertsson
mesh_terms: D003911:Dextrans; D010788:Photosynthesis; D011092:Polyethylene Glycols; D018724:Spinacia oleracea / Q000502:physiology* / Q000648:ultrastructure; D020524:Thylakoids / Q000378:metabolism / Q000648:ultrastructure*
chemical_list: D003911:Dextrans; D011092:Polyethylene Glycols