Photodynamic oxidation of Staphylococcus warneri membrane phospholipids: new insights based on lipidomics.

摘要: RATIONALE The photodynamic process involves the combined use of light and a photosensitizer, which, in presence oxygen, originates cytotoxic species capable oxidizing biological molecules, such as lipids. However, effect bacterial phospholipid profile by photosensitizer has never been reported. A lipidomic approach was used to study oxidation membrane phospholipids Staphylococcus warneri tricationic porphyrin [5,10,15-tris(1-methylpyridinium-4-yl)-20-(pentafluorophenyl)porphyrin triiodide, Tri-Py(+)-Me-PF]. METHODS S. (10(8) colony forming units mL(-1)) irradiated with white (4 mW cm(-2), 21.6 J cm(-2)) Tri-Py(+)-Me-PF (5.0 μM). Non-photosensitized bacteria were control (irradiated without porphyrin). After irradiation, total lipids extracted separated thin-layer chromatography (TLC). Isolated fractions lipid classes quantified phosphorus assay analyzed mass spectrometry (MS): off-line TLC/ESI-MS, hydrophilic interaction (HILIC)-LC/MS MS/MS. RESULTS most representative identified phosphatidylglycerols (PGs) cardiolipins (CLs). Lysyl-phosphatidylglycerols (LPGs), phosphatidylethanolamines (PEs), phosphatidylcholines (PCs) phosphatidic acids (PAs) also identified. treatment, an overall increase relative abundance PGs observed well appearance new oxidized from CLs, including hydroxy hydroperoxy derivatives. Formation high amounts hydroperoxides confirmed FOX2 assay. Photodynamic standards revealed formation dihydroperoxy derivatives, confirming CL warneri. CONCLUSIONS Membrane are molecular targets photoinactivation induced Tri-Py(+) -Me-PF. modification amount hydroxides indicate lethal damage caused photosensitized cells.