Oligonucleotide duplex stability controlled by the 7-substituents of 7-deazaguanine bases

Abstract

Oligonucleotides containing 7-substituted 7-deazaguanine residues (7-methyl, 7-iodol have been synthesized. The self-complementary octamer d(I(7)c(7)G-C)(4) containing 7-iodo-7-deaza-2'-deoxyguanosine forms a stabilized duplex compared to the parent oligomer d(G-C)(4) (Delta T-m = 10 degrees C). Also the complex between the oligodeoxynucleotide d(I(7)c(7)G(5)-G) and poly(C) is stabilized (Delta T-m = 10 degrees) over that of d(c(7)G(5)-G) with poly(C).