DUPLEX- AND TRIPLEX-FORMING PROPERTIES OF 4′-THIO-MODIFIED OLIGODEOXYNUCLEOTIDES

The melting temperatures (Tms) of a series of 4′-thio-modified oligodeoxynucleotides bound to complementary ssDNA, ssRNA and dsDNA have been determined. The results demonstrate an increase in Tm for the duplexes formed with RNA, but a reduction when bound to DNA. When forming a triplex with dsDNA, the greatest increases in Tm are observed when the 4′-thio-modifications are placed in contiguous stretches. © 1997 Elsevier Science Ltd.