- 作者: Ono, Akira ; 曹安邦 ; 甘魯生
- 作者服務機構: Dept. of Chemistry, Tokyo Metropolitan Univ., Tokyo, Japan
- 中文摘要: An oligonucleotide analog containing 2'-O- methylpseudoisocytidine (P) and 2'-O-methyluridine (X) in an alternated homopyrimidine sequence (P-X-)/sub 7/P-T can form triplexes with d-A-(G-A-)/sub 7/G single strand and [ d-A-(G-A-)/sub 7/G ] : [ d-C-(T -C-)/sub 7/T ] duplex in neutral conditions. An UV mixing titration showed an end point of two units of (P-X-)/sub 7/P-T to one unit of d-A-(G-A-)/sub 7/G. This indicates that a [ (P-X-)/sub 7/P-T ]□ [ d-A-(G-A-)/sub 7/G ] □ [ (P-X-)/sub 7/P-T ] is formed. The [ (P-X-)/sub 7/P-T ] □ [ d-A-(G-A-)/sub 7/G ]□ [ (P-X-)/sub 7/P-T ] triplex is stable in a 0.1M NaCl solution at neutral pH. However, the formation of triplex with [ (P-X-)/sub 7/P-T ] and a duplex [ d-A-(G-A-)/sub 7/G] □ [ d-C-(T-C-) /sub 7/T ] can be accomplished in solution also containing 5mM MgCl/sub 2/. CD spectra of both triplexes showed large negative bands at wavelength 210-230nm. Both triplexes can be detected by native gel electrophoresis. The thermal dissociation/ association results indicate that this triplex dissociates to the single strands directly without going through a stable duplex intermediate.
- 英文摘要: --
- 中文關鍵字: Triplex; Oligonucleotide; Methylpseudoisocytidine; Methyluridine
- 英文關鍵字: 三股螺旋;低聚核□酸