Effects of 8-methyl-2'-deoxyadenosine incorporation into quadruplex forming oligodeoxyribonucleotides.
In this paper we report the synthesis and the structural characterization of two modified oligodeoxyribonucleotides (ODNs), namely d(A8MeGGGT) and d(TA8MeGGGT), where A8Me represents a 8-methyl-2'-deoxyadenosine. Both ODNs have been studied by 1H NMR, CD spectroscopy and molecular modelling and shown to form fourfolds symmetric G-quadruplex structures, with all strands parallel and equivalent to each other. The complexes are characterized by thermal stabilities comparable to that of their natural counterparts. NOE patterns involving 8-methyl group in A8Me residues allowed us to define the main structural features at the 5'-end of the complexes. Particularly, inter- and intrastrand NOEs show a syn-orientation and a symmetrical arrangement of A8Me bases stacking on the adjacent G-tetrad.
Virgilio
Antonella
A
Dipartimento di Chimica delle Sostanze Naturali, Università degli Studi di Napoli Federico II, via D. Montesano 49, I-80131 Napoli, Italy.
Esposito
Veronica
V
Randazzo
Antonio
A
Mayol
Luciano
L
Galeone
Aldo
A
D002942:Circular Dichroism; D003839:Deoxyadenosines / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy; D008958:Models, Molecular; D009838:Oligodeoxyribonucleotides / Q000737:chemistry*
C502472:8-methyl-2'-deoxyadenosine; D003839:Deoxyadenosines; D009838:Oligodeoxyribonucleotides