Instability of coated vesicles in concentrated sucrose solutions.

A method of preparing homogeneous coated vesicles that eliminates the high sucrose concentrations heretofore used is presented. It is shown that sucrose at high concentrations dissociates the coat from coated vesicles. This reaction can explain the presence of empty coats observed with preparations obtained with high concentrations of sucrose. The protein and membrane lipid components have been analyzed by the intrinsic tryptophan and extrinsic diphenylhexatriene fluorescence, respectively. Analysis of mixtures of coated vesicles and baskets resolved the contributions of the two species to the fluorescence curves.