Structural and functional self-organization of Photosystem II in grana thylakoids

Biochim Biophys Acta. 2007 Sep;1767(9):1180-8. doi: 10.1016/j.bbabio.2007.05.009. Epub 2007 Jun 8.

Abstract

The biogenesis of the well-ordered macromolecular protein arrangement of photosystem (PS)II and light harvesting complex (LHC)II in grana thylakoid membranes is poorly understood and elusive. In this study we examine the capability of self organization of this arrangement by comparing the PSII distribution and antenna organization in isolated untreated stacked thylakoids with restacked membranes after unstacking. The PS II distribution was deduced from freeze-fracture electron microscopy. Furthermore, changes in the antenna organization and in the oligomerization state of photosystem II were monitored by chlorophyll a fluorescence parameters and size analysis of exoplasmatic fracture face particles. Low-salt induced unstacking leads to a randomization and intermixing of the protein complexes. In contrast, macromolecular PSII arrangement as well as antenna organization in thylakoids after restacking by restoring the original solvent composition is virtually identical to stacked control membranes. This indicates that the supramolecular protein arrangement in grana thylakoids is a self-organized process.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Chlorophyll / chemistry
  • Freeze Fracturing
  • Microscopy, Electron
  • Photosystem II Protein Complex / metabolism*
  • Proteins / chemistry
  • Spectrophotometry / methods
  • Spinacia oleracea
  • Temperature
  • Thylakoids / metabolism*
  • Time Factors

Substances

  • Photosystem II Protein Complex
  • Proteins
  • Chlorophyll