Investigation of B-Z transitions with DNA oligonucleotides containing 8-methylguanine

• Published in: Artificial DNA, PNA & XNA Vol. 5; no. 1; p. e28226
• Main Authors: Chen, Frederic Y-H, Park, Soyoung, Otomo, Haruka, Sakashita, Sohei, Sugiyama, Hiroshi
• Format: Journal Article
• Language: English
• Published: United States Taylor & Francis 2014
• Subjects: 8-methylguanine; B-Z transition; Base Sequence; CD spectra; Circular Dichroism; DNA, B-Form - chemistry; DNA, Z-Form - chemistry; Guanine - analogs & derivatives; Guanine - chemistry; Oligodeoxyribonucleotides - chemistry; Z-form DNA; Z-form DNA; B-Z transition; 8-methylguanine; CD spectra
• ISSN: 1949-095X; 1949-0968
• DOI: 10.4161/adna.28226

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.