The effect of cytochrome oxidase on lipid chain dynamics A nanosecond fluorescence depolarization study

Kazuhiko Kinosita, Suguru Kawato, Akira Ikegami, Satoshi Yoshida, Yutaka Orii

Research output: Contribution to journalArticle

34 Citations (Scopus)

Abstract

Molecular motions in membranes composed of purified cytochrome oxidase (EC 1.9.3.1) and synthetic lipid (l-α-dimyristoylphosphatidylcholine or l-α-dioleoylphosphatidylcholine) at various ratios were investigated with a lipophilic fluorescent probe 1,6-diphenyl-1,3,5-hexatriene. Nanosecond fluorescence depolarization kinetics of the probe showed that the rod-shaped probe molecules perform a fast wobbling motion (restricted rotation) in all membranes studied, presumably reflecting the motion of lipid acyl chains. At temperatures where the pure lipid was in the liquid-crystalline phase, presence of cytochrome oxidase reduced the angular range of the wobbling motion, whereas its rate; the wobbling diffusion constant, was unaffected. On the other hand, incorporation of the protein into lipid in the gel phase resulted in the increase in the wobbling diffusion constant while the range of the wobbling motion remained the same. A time-dependent view of lipid dynamics that accounts for the above findings, as well as the results of recent electron spin resonance and nuclear spin resonance studies of protein-lipid interactions, is proposed.

Original languageEnglish
Pages (from-to)7-17
Number of pages11
JournalBBA - Biomembranes
Volume647
Issue number1
DOIs
Publication statusPublished - 1981 Sep 21
Externally publishedYes

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Keywords

  • Boundary lipid
  • Cytochrome oxidase
  • Diphenyl hexatriene
  • Fluorescence depolarization
  • Lipid chain dynamics
  • Wobbling motion

ASJC Scopus subject areas

  • Biochemistry
  • Biophysics
  • Cell Biology
  • Medicine(all)

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