Interaction of photosensitizers with liposomes containing unsaturated lipid.
Small unilamellar liposomes were made of dipalmitoyl-phosphatidylcholine and dioleoyl-phosphatidylcholine, and photosensitized by a symmetrically or an asymmetrically substituted glycosilated tetraphenyl-porphyrin derivative. As differential scanning calorimetry and electron paramagnetic resonance spectroscopy (EPR) revealed these porphyrin derivatives were localized in different depth within the lipid bilayer. Both porphyrin derivatives were able to induce photoreaction and consequent structural changes in the membrane. 5-, 12-, or 16-doxyl stearic acid labeled lipid bilayers were applied and the efficiency of photoinduced reaction was followed by the decay of their EPR signal amplitude. Light dose-dependent destruction of nitroxide radical proved to be dependent on the position of spin label. In this process the porphyrin localized in closer connection with the double bond of unsaturated fatty acid was more effective. EPR signal decay was also dependent on the unsaturated fatty acid content of the liposome and the oxygen saturation of the solvent.
Voszka
István
I
Institute of Biophysics and Radiation Biology, Semmelweis University, Puskin Street 9, POB 263, Budapest H-1444, Hungary. voszka@puskin.sote.hu
Budai
Marianna
M
Szabó
Zsófia
Z
Maillard
Philip
P
Csík
Gabriella
G
Gróf
Pál
P
D015060:1,2-Dipalmitoylphosphatidylcholine / Q000737:chemistry*; D002152:Calorimetry, Differential Scanning; D003497:Cyclic N-Oxides; D004578:Electron Spin Resonance Spectroscopy; D005697:Galactosides / Q000737:chemistry*; D005960:Glucosides / Q000737:chemistry*; D008027:Light; D008051:Lipid Bilayers / Q000737:chemistry*; D008081:Liposomes / Q000737:chemistry*; D008560:Membrane Fluidity; D010713:Phosphatidylcholines / Q000737:chemistry*; D017319:Photosensitizing Agents / Q000737:chemistry*; D011166:Porphyrins / Q000737:chemistry*; D013113:Spin Labels; D005464:Fluorobenzenes; D005466:Fluorocarbons
D015060:1,2-Dipalmitoylphosphatidylcholine; D003497:Cyclic N-Oxides; D005697:Galactosides; D005960:Glucosides; D008051:Lipid Bilayers; D008081:Liposomes; D010713:Phosphatidylcholines; D017319:Photosensitizing Agents; D011166:Porphyrins; D013113:Spin Labels; C519710:5,10,15,20-tetrakis(4-glucosylphenyl)porphyrin; C519711:5,10,15-(4-galactosylphenyl)-20-(2',3',4',5',6'-pentafluorophenyl)porphyrin; D005464:Fluorobenzenes; D005466:Fluorocarbons; C037404:12-doxylstearic acid; C005072:5-doxylstearic acid; C032363:16-nitroxystearic acid; C017251:1,2-oleoylphosphatidylcholine