title: Investigation of B-Z transitions with DNA oligonucleotides containing 8-methylguanine.
abstract: Among various Z-form DNA inducers, such as transition metal complexes, polyamines and high ionic concentrations, 8-methylguanine have received attention as efficient chemical modifications. Although it is clear that m8-modified guanine base markedly stabilizes the Z conformation of short oligonucleotides under physiological salt conditions, how sequence composition affects the preference of Z-DNA is still not well established. In this study, various oligomers of d(CG)n or d(GC)n containing either 8-methylguanine in a different position were synthesized and their capacity of stabilizing Z-DNA were evaluated by CD spectra and then compared with each other. It is was found out that the Z-DNA stabilizing effect depend on the order of arrangement of m(8)G and m(8)rG in DNA strands and the center position is the most effective to stabilize the Z-DNA and promote the B to Z transition.
authors.affiliation: a Department of Chemistry; National Taiwan University; Taipei, Taiwan.
authors.forename: Frederic Y-H
authors.initials: FY
authors.lastname: Chen
authors.forename: Soyoung
authors.initials: S
authors.lastname: Park
authors.forename: Haruka
authors.initials: H
authors.lastname: Otomo
authors.forename: Sohei
authors.initials: S
authors.lastname: Sakashita
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Sugiyama
mesh_terms: D001483:Base Sequence; D002942:Circular Dichroism; D059371:DNA, B-Form / Q000737:chemistry*; D043542:DNA, Z-Form / Q000737:chemistry*; D006147:Guanine / Q000031:analogs & derivatives* / Q000737:chemistry; D009838:Oligodeoxyribonucleotides / Q000737:chemistry*
chemical_list: D059371:DNA, B-Form; D043542:DNA, Z-Form; D009838:Oligodeoxyribonucleotides; C066771:8-methylguanine; D006147:Guanine
keywords: 8-methylguanine; B-Z transition; CD spectra; Z-form DNA