| In this dissertation, three well-defined vesicle sizes (small, medium and large) were prepared and characterized using dynamic light scattering measurements. The phosphate assay of Bartlett (1959) was used to determine the phospholipid concentration. Spectrophotometric titrations with the dye o-methyl red and the different vesicle sizes show that the binding of the zwitterionic form of o-methyl red to vesicles with different radii is not affected by the curvature [KAH = 1.5-1.8 x 103 M-1). The binding of the anionic form of o-methyl red to the vesicles, however, was found to be much weaker than that of the zwitterion (KA = 27 M-l and 11 M-l, for the SUVs and the MUVs respectively). The weaker binding of the anion to MUVs as compared to SUVs indicates that the curvature of membrane systems has a significant effect on the binding of small charged molecules. |
