Synthesis of oligo-DNA containing hydrophilic porphyrin in the main chain, and its energy transfer behaviour in duplex state

摘要

DNA is one of the best candidates as building blocks for bottom-up approach to nanometre size architecture in nanotechnology. In natural photosynthetic system, the arrangement of porphyrin derivatives with regulated distances, orders and orientations provides an efficient photon-energy collecting and transmission. We have studied about chromophore arrangement on DNA assembly as a simple artificial model of photosynthetic and photo-energy transmission systems. In order to prepare DNAs containing porphyrin residues at desired sites, a hydrophilic porphyrin amidite derivative, which can be utilised on automatic DNA synthesizer, was synthesised. The porphyrin amidite derivative was applied for automatic DNA synthesizer to give single-strand DNA (ssDNA) containing porphyrin set in the chain. The obtained ssDNA was mixed with complementary counter strand having another chromophore black hole quencher-3 (BHQ-3) to form duplex by self-assembly. The quenching behaviour by energy transfer from the porphyrin to BHQ-3 was monitored by fluorescence measurement.