SYNTHESIS AND CHARACTERIZATION OF A SET OF FOUR DODECADEOXYRIBONUCLEOSIDE UNDECAPHOSPHATES CONTAINING 0°-METHYLGUANINE OPPOSITE ADENINE, CYTOSINE, GUANINE, AND THYMINE

Abstract

A set of four self-complementary dodecanucleoside undecaphosphates, d[CGNGAATTC(O6Me)GCG] (1), where N = A, C, G, or T, has been synthesized by a phosphoramidite procedure. Each sequence forms a stable duplex, with a Im between 19 and 26°C lower than the Tm Of the "parent" molecule d(CGCGAATTCGCG). The lowest melting sequence is the N=T molecule; the overall order is N = C>A>G> T. Enus 0°-met hylation of guanine creates a region of localized instability in DNA regardless of the base opposite the lesion.