Efficient solid-phase synthesis of oligodeoxynucleotides having a 5'-terminal 2,2,7-trimethylguanosine pyrophosphate linkage.

A 5'-terminal 2,2,7-trimethylguanosine (TMG) cap structure plays an important role in transport of TMG-capped snRNAs from the cytoplasm to the nucleus in living cells. This property can be expected to be used for carrying artificial nucleic acids into the nucleus in gene therapy. In this paper, a new TMG-capping reagent 1 was developed and used for the synthesis of oligodeoxynucleotides having a 5'-terminal TMG-capped pyrophosphate linkage (m(3)(2,2,7)G(5')pp-DNA) lacking one phosphate group using a silyl-type linker on polymer supports.