SPECTROSCOPY AND RECOGNITION CHEMISTRY OF MICELLES FROM MONOALKYL PHOSPHORYL NUCLEOSIDES

We describe the properties of aqueous micelles obtained from n-alkyl p hosphoryl nucleosides, in particular n-hexadecylphosphoryladenosine (C 16-AMP), uridine (C16-UMP), and -cytidine (C16-CMP). These compounds w ere obtained enzymatically. It is shown that each of these compounds f orm micelles spontaneously in water with a critical micelle concentrat ion in the range of 20-35 mu M and an aggregation number of 69, which indicates that the chemical structure of the bases has no significant influence on the aggregation behavior. UV-absorption and circular dich roic measurements suggest that the nucleoside is in an aqueous environ ment, as expected from the amphiphilic character of the compounds. UV absorption suggests a moderate self-stacking among the bases for each type of micelle. When we mixed micelles bearing complementary bases wi th each other (e.g., C16-AMP with C16-CMP), a weak hypochromic effect was observed, which can be taken as an indication of complementary bas e interaction. However, such electronic perturbation was observed also in noncomplementary bases, e.g., when C16-CMP micelles were mixed wit h C16-UMP micelles. These micelle data are compared with the correspon ding data obtained with liposomes obtained from phosphatidyl nucleosid es. All together, these: data illustrate a novel type of polymeric nuc leoside interaction with which no covalent bonds form among the monome rs, and in which the nucleobases are distributed as a supramolecular s pherical aggregate.