title: Structural investigations on the anti-HIV G-quadruplex-forming oligonucleotide TGGGAG and its analogues: evidence for the presence of an A-tetrad.
abstract: Several anti-HIV aptamers adopt DNA quadruplex structures. Among these, "Hotoda's aptamer" (base sequence TGGGAG) was one of the first to be discovered. Although it has been the topic of some recent research, no detailed structural investigations have been reported. Here we report structural investigations on this aptamer and analogues with related sequences, by using UV, CD, and NMR spectroscopy as well as electrophoretic techniques. The addition of a 3'-end thymine has allowed us to obtain a single, investigable quadruplex structure. Data clearly point to the presence of an A-tetrad. Furthermore, the effects of the incorporation of an 8-methyl-2'-deoxyguanosine at the 5'-end of the G-run were investigated.
authors.affiliation: Dipartimento di Chimica delle Sostanze Naturali, Università degli Studi di Napoli Federico II, Via D. Montesano 49, I-80131 Napoli, Italy.
authors.forename: Antonella
authors.initials: A
authors.lastname: Virgilio
authors.forename: Veronica
authors.initials: V
authors.lastname: Esposito
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Citarella
authors.forename: Luciano
authors.initials: L
authors.lastname: Mayol
authors.forename: Aldo
authors.initials: A
authors.lastname: Galeone
mesh_terms: D000163:Acquired Immunodeficiency Syndrome / Q000188:drug therapy; D019380:Anti-HIV Agents / Q000737:chemistry*; D052157:Aptamers, Nucleotide / Q000737:chemistry*; D001483:Base Sequence; D002942:Circular Dichroism; D003849:Deoxyguanosine / Q000031:analogs & derivatives* / Q000737:chemistry; D054856:G-Quadruplexes; D006678:HIV / Q000187:drug effects; D006801:Humans; D008958:Models, Molecular; D019906:Nuclear Magnetic Resonance, Biomolecular; D013056:Spectrophotometry, Ultraviolet
chemical_list: C104538:8-methyl-2'-deoxyguanosine; D019380:Anti-HIV Agents; D052157:Aptamers, Nucleotide; D003849:Deoxyguanosine