Fatty acid-indole fluorescent derivatives as probes to measure the polarity of interfaces containing Gangliosides

LUIS BAGATOLLI; GUILLERMO MONTICH; MARIO RAVERA; JORGE PEREZ; GERARDO FIDELIO

CHEMISTRY AND PHYSICS OF LIPIDS

ELSEVIER IRELAND LTD

Lugar: Amsterdam; Año: 1995 vol. 78 p. 193 - 193

0009-3084

he fluorescence emission properties of three indole derivative probes N-2-(3-indolyl)ethyl-tetradecanoyl carboxamide (N-myrTAM), 2-tetradecanoyl carboxamidyl-3-(3-indolyl)propanoic acid (N-myrTRP) and 11-N(2-[3-in-dolyl]ethylamino)-9-en-methyloxy carbonyldecenate (11-TAMundec) were studied in solvents of different polarities in pure lysophosphatidylcholine micelles (lysoPC) and in total brain gangliosides (TBG) micelles using steady-state and phase-modulation fluorometry. By comparing the fluorescence emission spectra in solvent mixtures with the spectra in lipid micelles it is concluded that the probes detect a more polar environment in TBG compared to lysoPC micelles. Quenching experiments with acrylamide indicate that the indole group of N-myrTRP and N-myrTAM are more exposed to the aqueous medium than the indole group of 11-TAMundec both in lysoPC and TBG micelles. Quenching of the indole fluorescence with brominated fatty acid