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

J Biol Chem. 2015 Jul 24;290(30):18429-37. doi: 10.1074/jbc.M115.663872. Epub 2015 Jun 8.

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.

Keywords: PS I-LHC II supercomplex; electron transfer complex; membrane energetics; membrane protein; photosynthesis; photosystem I; plant biochemistry; stryrene-maleic acid copolymer.

Publication types

  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Cell Membrane / chemistry
  • Chloroplast Proton-Translocating ATPases / chemistry
  • Chloroplasts / chemistry*
  • Cytochrome b6f Complex / chemistry
  • Cytochrome b6f Complex / isolation & purification*
  • Light
  • Light-Harvesting Protein Complexes / chemistry
  • Light-Harvesting Protein Complexes / isolation & purification*
  • Maleic Anhydrides / chemistry
  • Photosynthesis*
  • Photosystem I Protein Complex / chemistry*
  • Photosystem I Protein Complex / isolation & purification
  • Photosystem II Protein Complex / chemistry*
  • Photosystem II Protein Complex / isolation & purification
  • Polystyrenes / chemistry
  • Spectrometry, Fluorescence
  • Spinacia oleracea / chemistry
  • Thylakoids / chemistry

Substances

  • Light-Harvesting Protein Complexes
  • Maleic Anhydrides
  • Photosystem I Protein Complex
  • Photosystem II Protein Complex
  • Polystyrenes
  • Styromal
  • Cytochrome b6f Complex
  • Chloroplast Proton-Translocating ATPases