Papers by Author: Tomohisa Moriguchi

Abstract: A novel stem-loop structured fluorescent oligoDNA probe (molecular beacon probe) bearing a silylated pyrene derivative at C-5 position of deoxyuridine has been synthesized. The fluorescently labeled modified nucleoside has been incorporated into two consecutive positions in the stem segment of the DNA using an automated DNA synthesizer. The resulting modified DNA exhibited an excimer fluorescent signal upon binding to the fully matched complementary DNA strand. The excimer emission was, however, effectively quenched while it stays alone or it hybridizes to a single base mismatched complementary target.

Abstract: We have synthesized novel perylene derivatives bearing a silyl function with modifiable functional groups as a feasible material for visualizing biological substances. The fluorescent perylene derivative was coupled to C-5 position of pyrimidine nucleotide and the nucleotide was subsequently incorporated to the middle position of oligoDNA using an automated DNA synthesizer. Also, the derivative was coupled with a cholesterol analog with different length of linking alkyl function. The resulting modified fluorescent oligoDNA exhibited a small change in its fluorescent signal upon hybridization with the complementary oligoDNA. While the cholesterol analogs bearing the silylated perylene exhibited marked fluorescent signal in living cells. The signal is stronger in the analog having longer linker function compared to the analog having shorter linker function. In each case, however, the signal was much prominent compared to that of dehydroergosterol (DHE), a fluorescent cholesterol analog widely used in biological study.