| Abstract
| - This work applied two steady-state fluorescence techniques to detect nanoscopic membrane domains in a binarydimyristoylphosphocholine (DMPC)-cholesterol system and a ternary dioleoylphosphocholine (DOPC)-dipalmitoylphosphocholine (DPPC)-cholesterol system. A polarity-induced spectral shift in the emission spectra of 1-myristoyl-2-[12-[(5-dimethylamino-1-naphthalenesulfonyl)amino]dodecanoyl]-sn-glycero-3-phosphocholine (DAN-PC) in combination with a Förster resonance energy transfer (FRET) assay agreed with the phase diagrams that have beenpublished for these systems and were observed to be useful tools in the detection of membrane heterogeneities. TheDAN-PC/dehydroergosterol (DHE) FRET pair was found to be best suited for use with these steady-state techniquesbecause of their differential partitioning between phases, although a high acceptor concentration was needed to obtainaccurate measurements. In the binary system, this high probe concentration was found to be perturbing, but in morerepresentative ternary systems, the high probe concentration no longer disrupted the phase behavior of the system.This FRET pair allowed for the calculation of nanometer-scale domain sizes in model ternary systems, using the twosteady-state fluorescence techniques along with a clear and straightforward model.
|
