Synthesis and properties of oligodeoxynucleotides possessing N-phosphoryl groups

This paper deals with the synthesis and properties of oligodeoxynucleotides of a Dickerson-Drew sequence, d(CGCGAATTCGCG), in which one of the four cytosine bases has been replaced with an N-phosphorylated or N-di-ethylphosphorylated cytosine base in order to study the effect of the N-phosphoryl or N-diethoxyphosphoryl group on their structural property and hybridization affinity. The CD spectra of these self-complementary duplexes showed the typical B DNA-type shape with very minor changes. In contrast, it was found from T-m experiments that N-phosphoryl groups destabilized the DNA duplexes significantly through steric hindrance and electronic repulsion. ((C) Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003).