Reverse Micellar Organization and Dynamics: A Wavelength-Selective Fluorescence Approach

Abstract

Wavelength-selective fluorescence comprises a set of approaches based on the red edge effect in fluorescence spectroscopy, which can be used to directly monitor the environment and dynamics around a fluorophore in a complex biological system. A shift in the wavelength of maximum fluorescence emission toward higher wavelengths, caused by a shift in the excitation wavelength toward the red edge of the absorption band, is termed the red edge excitation shift (REES). This effect is mostly observed with polar fluorophores in motionally restricted media such as very viscous solutions or condensed phases. We have previously shown that REES and related techniques (wavelength-selective fluorescence approach) offer a novel way to monitor organization and dynamics of membrane- and micelle-bound probes and peptides. In this paper, we report REES of NBD-PE, a phospholipid whose headgroup is covalently labeled with the 7-nitrobenz-2-oxa-1,3-diazol-4-yl (NBD) moiety, when incorporated into reverse micelles formed by sod...