EFFECT OF NUCLEOTIDES ON THE CHARGE-TRANSFER FLUORESCENCE OF P-N,N-DIMETHYLAMINOSTYRYL)-N-VINYLBENZYLPYRIDINIUM CHLORIDE

Addition of the cyclic nucleotides cAMP and cGMP to aqueous solutions of p-N,N-dimethylaminostyryl)-N-vinylbenzylpyridinium chloride (1) dra matically enhanced the fluorescence quantum yield of 1 with concomitan t slight red shifts of the lambda(max), and had slight hyperchromic an d bathochromic effects on the absorbance of 1. In contrast, D-ribose-5 -phosphate had no such effects. These results suggest that 1 preferent ially associates with nucleotides in aqueous solution, with equilibriu m constants for cAMP and cGMP of 212 +/- 46 and 285 +/- 18 M(-1), resp ectively, Thus, dye 1 may serve as a starting point for the developmen t of more sensitive and specific probes for cyclic nucleotides.