The Susceptibility of Non-UV Fluorescent Membrane Dyes to Dynamical Properties of Lipid Membranes

摘要: Fluorescence spectroscopy and microscopy are powerful techniques to detect dynamic properties in artificial natural lipid membrane systems. Unfortunately, most fluorescent dyes that sense dynamically relevant parameters UV sensitive. Their major disadvantage is a high susceptibility fluorescence bleaching. Additionally, the risk for hazardous damages biological components generally increases with decreasing excitation wavelength. Therefore use of non-UV–sensitive would provide significant advantage, particularly applications microscopy, which usually implies local intensities. We applied steady-state several non-UV compare emission characteristics. Small unilamellar liposomes (composed egg yolk phosphatidylcholine) served as model system membranes. The membranes were varied by two independent parameters: intrinsic cholesterol content (0–50 mol%) temperature (10–50°C). tested four dyes: 9-diethylamino-5H-benzophenoxazine-5-one (Nile Red), 4-(dicyanovinyl)julolidine (DCVJ), N-(3-triethylammoniumpropyl)-4-(4-(dibutylamino)styryl) pyridinium dibromide (FM 4-64), 1,1′-dioctadecyl-3,3,3′,3′-tetramethylindocarbocyanine perchlorate (DiIC18). also three derivatives DiIC18: DiIC16 DiIC12 differ acyl chain length Fast-DiIC18 provides double bonds between hydrocarbon atoms. spectral results compared established characteristics anisotropy 1-6-phenyl-1,3,5,-hexatrien (DPH), DPH (TMA-DPH COO−-DHP), generalized polarization 6-dodecanoyl-2-dimethyl-aminonaphthalene (Laurdan). Our indicate do not reveal direct manner. However, make DiIC18, Nile Red, DCVJ promising probes microscopic detection lateral organization, an indirect indicator dynamics. In particular, DiIC18 showed very selective shifts spectra at defined temperatures contents have been reported elsewhere.