title: Direct visualization of solid ordered domains induced by polyene antibiotics in giant unilamellar vesicles.
abstract: Polyene antibiotics isolated from Streptomyces are frequently used in treatment of mycoses. Confocal fluorescence microscopy has been employed to investigate the influence of polyene macrolide antibiotics nystatin, amphotericin B, and filipin on the phase separation in giant unilamellar vesicles. It has been demonstrated that nystatin produced the solid ordered domains in vesicles made from DOPC/Chol, DOPC/Chol/SM, and POPC while DOPC vesicles remained homogenous in the presence of polyene antibiotics. The ability of various polyenes to produce the solid ordered phase in POPC membranes has been compared. It has been shown that amphotericin B produced phase separation at lower concentration as compared with nystatin and filipin. Filipin was less effective in promotion of gel domains. The observed efficiency of polyene antibiotics to induce phase separation in lipid bilayers correlates with their biological activity. Present findings probably indicate the limitations of using of polyenes as fluorescence membrane probes for determination of strerol-enriched domains in plasma membrane of live cells.
authors: Institute of Cytology of the Russian Academy of Sciences, Tikhoretsky Aveneu 4, St. Petersburg 194064, Russia. Electronic address: evchulkov@mail.com.
authors: Evgeny G
authors: EG
authors: Chulkov
authors: Institute of Cytology of the Russian Academy of Sciences, Tikhoretsky Aveneu 4, St. Petersburg 194064, Russia.
authors: Svetlana S
authors: SS
authors: Efimova
authors: Institute of Cytology of the Russian Academy of Sciences, Tikhoretsky Aveneu 4, St. Petersburg 194064, Russia.
authors: Ludmila V
authors: LV
authors: Schagina
authors: Institute of Cytology of the Russian Academy of Sciences, Tikhoretsky Aveneu 4, St. Petersburg 194064, Russia.
authors: Olga S
authors: OS
authors: Ostroumova
mesh_terms: D000666:Amphotericin B / Q000737:chemistry*; D000900:Anti-Bacterial Agents / Q000737:chemistry*; D021962:Membrane Microdomains; D008856:Microscopy, Fluorescence / Q000379:methods*; D009761:Nystatin / Q000737:chemistry*; D044367:Phase Transition; D010743:Phospholipids / Q000737:chemistry*; D011090:Polyenes / Q000737:chemistry*; D053835:Unilamellar Liposomes / Q000737:chemistry*
chemical_list: D000900:Anti-Bacterial Agents; D010743:Phospholipids; D011090:Polyenes; D053835:Unilamellar Liposomes; D009761:Nystatin; D000666:Amphotericin B
keywords: Giant unilamellar vesicles; Lipid domains; Membranes; Phase separation; Polyene antibiotics