title: 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.
abstract: 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.
authors.affiliation: From the Department of Biological Sciences, Biochemistry and Molecular Biology Section, Louisiana State University, Baton Rouge, Louisiana 70803.
authors.forename: Adam J
authors.initials: AJ
authors.lastname: Bell
authors.affiliation: From the Department of Biological Sciences, Biochemistry and Molecular Biology Section, Louisiana State University, Baton Rouge, Louisiana 70803.
authors.forename: Laurie K
authors.initials: LK
authors.lastname: Frankel
authors.affiliation: From the Department of Biological Sciences, Biochemistry and Molecular Biology Section, Louisiana State University, Baton Rouge, Louisiana 70803 btbric@lsu.edu.
authors.forename: Terry M
authors.initials: TM
authors.lastname: Bricker
mesh_terms: D002462:Cell Membrane / Q000737:chemistry; D025222:Chloroplast Proton-Translocating ATPases / Q000737:chemistry; D002736:Chloroplasts / Q000737:chemistry*; D045346:Cytochrome b6f Complex / Q000737:chemistry / Q000302:isolation & purification*; D008027:Light; D045342:Light-Harvesting Protein Complexes / Q000737:chemistry / Q000302:isolation & purification*; D008299:Maleic Anhydrides / Q000737:chemistry; D010788:Photosynthesis; D045331:Photosystem I Protein Complex / Q000737:chemistry* / Q000302:isolation & purification; D045332:Photosystem II Protein Complex / Q000737:chemistry* / Q000302:isolation & purification; D011137:Polystyrenes / Q000737:chemistry; D013050:Spectrometry, Fluorescence; D018724:Spinacia oleracea / Q000737:chemistry; D020524:Thylakoids / Q000737:chemistry
chemical_list: D045342:Light-Harvesting Protein Complexes; D008299:Maleic Anhydrides; D045331:Photosystem I Protein Complex; D045332:Photosystem II Protein Complex; D011137:Polystyrenes; C025704:Styromal; D045346:Cytochrome b6f Complex; D025222:Chloroplast Proton-Translocating ATPases
keywords: PS I-LHC II supercomplex; electron transfer complex; membrane energetics; membrane protein; photosynthesis; photosystem I; plant biochemistry; stryrene-maleic acid copolymer