Surface Specific Phosphate Cleavage of a Substrate Functionalized Vesicular Surfactant

摘要

Anionic vesicles of 1,2-dipalmitoyl-3-glyceryl-p-nitrophenyl phosphate release approx. 50% of p-nitrophenoxide ions (PNPO-) at pH 11.8 by cleavage at their exovesicular surfaces. The endovesicular surfaces are not attacked because the vesicles are impermeable to the hydroxide ions. The fluorescence of vesicles are impermeable to the hydroxide ions. The fluorescence of vesicle-entrapped riboflavin is not quenched by hydroxide ions for the same reason. In the presence of excess cetyltrimethylammonium chloride, however, the vesicles become permeable to hydroxide and the residual endovesicular PNPO- is rapidly cleaved. Entrapped riboflavin is also attacked under these conditions.