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Abstract

1The quantum yield of 1-anilino-8-naphthalenesulfonate associated with native and lipid-depleted sarcoplasmic vesicles is nearly identical. The slight increase of the average apparent dissociation constant of the interaction of this dye with lipid-depleted vesicles is accompanied by a decrease in the number of binding sites for the dye. 2Oleic acid is a noncompetitive inhibitor of the anilino-naphthalenesulfonate binding to native and lipid-depleted sarcoplasmic vesicles. 3Rising temperatures decrease the quantum yield and increase the average apparent dissociation constant. 4The polarisation of the fluorescence of membrane-bound anilino-naphthalenesulfonate reaches relatively high values with a significant increment for lipid-depleted sarcoplasmic vesicles. There is only a slight temperature dependence and no viscosity dependence for both native and lipid-depleted vesicles. The polarisation is reduced by rising concentrations of anilino-naphthalenesulfonate. 5Energy transfer measurements indicate that the dye is located very closely to the membrane-bound tryptophan, suggesting a donor-acceptor distance of 2 nm.