A novel squarylium dye for monitoring oxidative processes in lipid membranes

J Fluoresc. 2009 Nov;19(6):1017-23. doi: 10.1007/s10895-009-0501-z. Epub 2009 Jun 10.

Abstract

A novel squaraine probe SQ-1 has been found to be appropriate for monitoring the peroxidation processes in membrane systems. Formation of free radicals was triggered by methemoglobin (metHb) or cytochrome c (cyt c) binding to the model lipid membranes composed of zwitterionic lipid phosphatidylcholine (PC) and anionic lipid cardiolipin (CL). Protein association with the lipid vesicles was followed by drastic quenching of SQ-1 fluorescence. The observed spectral changes were suppressed in the presence of free radical scavengers, butylated hydroxytoluene (BHT) and thiourea (TM) suggesting that SQ-1 decolorization can be attributed to its reactions with lipid radicals.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Birds
  • Cardiolipins / chemistry
  • Cattle
  • Coloring Agents / chemistry
  • Cyclobutanes / chemistry*
  • Cytochromes c / chemistry
  • Fluorescence
  • Free Radicals / chemistry
  • Horses
  • Indoles / chemistry*
  • Lipid Peroxidation
  • Membrane Lipids / chemistry*
  • Methemoglobin / chemistry
  • Models, Chemical
  • Oxidation-Reduction
  • Phenols / chemistry
  • Phosphatidylcholines / chemistry
  • Spectrometry, Fluorescence
  • Ultraviolet Rays
  • Unilamellar Liposomes / chemistry*

Substances

  • Cardiolipins
  • Coloring Agents
  • Cyclobutanes
  • Free Radicals
  • Indoles
  • Membrane Lipids
  • Phenols
  • Phosphatidylcholines
  • Unilamellar Liposomes
  • squaraine
  • Cytochromes c
  • Methemoglobin