Fluorescence quenching in lipid micelles and bilayers: Evaluation of bimolecular rate constants

Dynamic quenching of fluorophores and quenchers in lipid micelles and bilayers can yield information about the bimolecular rate constant for the quenching reaction, and hence information about the microviscosity of the fluorophore-quencher environment. When the fluorophore and quencher have relatively fixed transverse positions in the bilayer, the analysis of Sikaris et al. (Chem. Phys. Lipids. 29 (1981) 23) can be used to separate the microviscosity and proximity contributions to quenching. We now extend this method to show explicitly the effect of static quenching on the analysis. We show by simulation and experiment that a correction factor must be included when static quenching contributes to the observed quenching efficiency.