Evaluation of the 2 NH2A—T Pair in Hybridization, I Synthesis of the D N A / R N A Hybrid Oligomers Containing 2-Aminoadenosines

Kaeko Kikuchi, Yoshio Taniyama, and Ryuji Marumoto* Biotechnology Laboratories, Central Research Division, Takeda Chem. Ind. Ltd., Jusohonmachi, Yodogawa-ku, Osaka 532, Japan Z. Naturforsch. 43b, 623-630 (1988); received October 12, 1987/February 1, 1988 DNA Probe, Hybridization, 2-Aminoadenosine, CD Spectra, DNA/RNA Hybrid Oligomer DNA decamers containing 2-aminoadenosine were synthesized. Oligonucleotide duplexes including the 2 NH2A—T base pairs were prepared and their Tm profile examined. Contrary to expectation, elevation of the Tm value by the 2 NH2 group is very small in DNA/RNA duplexes. From the CD spectra measurement, we assume that the distortion of the B-DNA structure caused by scattered DNA/RNA base pairing diminishes the efficient hydrogen bonding and base stacking of the duplexes. It was also found that the DNA duplexes containing 2-aminoadenosine hybrids are considerably resistant to ribonuclease T2 or nuclease P I digestion.