FLUORESCENCE AND NMR-STUDIES OF THE EFFECT OF A BILE-ACID DIMER ON THE MICELLIZATION OF BILE-SALTS

The dimerization of bile salts is known to be the critical step in the formation of bile salt micelles. The influence of a sodium cholate di mer, synthesized by linking two cholic acid molecules via spacer, on t he micellization processes of selected bile salts has been investigate d. Fluorescence studies of a pyrene probe and NMR spin-lattice relaxat ion time experiments have been carried out to determine the critical m icellar concentration (cmc) of sodium cholate and sodium glycocholate upon the addition of various amounts of the dimer. The cmc's of the bi le salts are significantly lowered by the presence of this dimer, whic h indicates that the sodium cholate dimer can facilitate the micelliza tion of bile salts.