Formation of Poly[d(A-T)2] Specific Z-DNA by a Cationic Porphyrin.
Typical CD spectrum of the right-handed poly[d(A-T)2] was reversed when trans-bis(N-methylpyrimidium-4-yl)diphenyl porphyrin (trans-BMPyP) was bound, suggesting that the helicity of the polynucleotide was reversed to the left-handed form. The formation of the left-handed Z-form poly[d(A-T)2] was confirmed by (31)P NMR, in which a single (31)P peak of B-form poly[d(A-T)2] was split into two peaks, which is similar to the conventional B-Z transition of poly[d(G-C)2] induced by the high ionic strength. The observed B-Z transition is unique for poly[d(A-T)2]. The other polynucleotides, including poly[d(G-C)2], poly(dG)·poly(dC) and poly(dA)·poly(dT) remained as the right-handed form in the presence of the same porphyrin. This observation suggests that the porphyrin array that was formed along the poly[d(A-T)2] provides a template to which left-handed poly[d(A-T)2] is associated with an electrostatic interaction.
Department of Chemistry, Yeungnam University 212 Dae-dong, Gyeongsan City, Gyeong-buk, 712-749, Republic of Korea.
Yoon Jung
YJ
Jang
Department of Chemistry, Yeungnam University 212 Dae-dong, Gyeongsan City, Gyeong-buk, 712-749, Republic of Korea.
Changyun
C
Lee
Department of Chemistry, Yeungnam University 212 Dae-dong, Gyeongsan City, Gyeong-buk, 712-749, Republic of Korea.
Seog K
SK
Kim
D001665:Binding Sites; D002412:Cations; D043542:DNA, Z-Form / Q000737:chemistry*; D007536:Isomerism; D008956:Models, Chemical; D008958:Models, Molecular; D009690:Nucleic Acid Conformation; D011089:Polydeoxyribonucleotides / Q000737:chemistry*; D011166:Porphyrins / Q000737:chemistry*
D002412:Cations; D043542:DNA, Z-Form; D011089:Polydeoxyribonucleotides; D011166:Porphyrins; C098036:poly(d(A-T))2