Temperature dependence of the lipid packing in thylakoid membranes studied by time- and spectrally resolved fluorescence of Merocyanine 540

Sashka B. Krumova, Rob B.M. Koehorst, Attila Bóta, Tibor Páli, Arie van Hoek, Gyozo Garab, Herbert van Amerongen

Research output: Contribution to journalArticle

22 Citations (Scopus)

Abstract

The lipid packing of thylakoid membranes is an important factor for photosynthetic performance. However, surprisingly little is known about it and it is generally accepted that the bulk thylakoid lipids adopt the liquid-crystalline phase above - 30 °C and that a phase transition occurs only above 45 °C. In order to obtain information on the nature of the lipid microenvironment and its temperature dependence, steady-state and time-resolved fluorescence measurements were performed on the fluorescence probe Merocyanine 540 (MC540) incorporated in isolated spinach thylakoids and in model lipid systems (dipalmitoyl phosphatidylcholine and dioleoyl phosphatidylethanolamine) adopting different phases. It is demonstrated that the degree and way of incorporation differs for most lipid phases - upon selective excitation at 570 nm, the amplitude of the fluorescence component that corresponds to membrane-incorporated MC540 is about 20% in gel-, 60% in rippled gel-, and 90% in liquid-crystalline and inverted hexagonal phase, respectively. For thylakoids, the data reveal hindered incorporation of MC540 (amplitude about 30% at 7 °C) and marked spectral heterogeneity at all temperatures. The incorporation of MC540 in thylakoids strongly depends on temperature. Remarkably, above 25 °C MC540 becomes almost completely extruded from the lipid environment, indicating major rearrangements in the membrane.

Original languageEnglish
Pages (from-to)2823-2833
Number of pages11
JournalBiochimica et Biophysica Acta - Biomembranes
Volume1778
Issue number12
DOIs
Publication statusPublished - Dec 1 2008

Keywords

  • Lipid packing
  • Merocyanine 540
  • Thylakoid membrane

ASJC Scopus subject areas

  • Biophysics
  • Biochemistry
  • Cell Biology

Fingerprint Dive into the research topics of 'Temperature dependence of the lipid packing in thylakoid membranes studied by time- and spectrally resolved fluorescence of Merocyanine 540'. Together they form a unique fingerprint.

  • Cite this