title: Combination and cleavage of HBV DNA fragments by triple helix-forming oligonucleotides modified with manganese porphyrin in vitro.
abstract: OBJECTIVE
  To observe the ability of triple helix-forming oligonucleotides (TFOs) modified with manganese porphyrin to combine with and cleave HBV DNA fractions.
  
  
  METHODS
  TFO were modified with manganese porphyrin and acridines, and then reacted with the (32)P labeled HBV DNA fragments at 37 degrees C in vitro (pH 7.4). Electrophoretic mobility shift assays and DNase I footprinting tests were used to show the affinity and specificity of TFO to bind to target sequences. The ability of TFO to cleave HBV DNA fragments was tested by cleavage experiments.
  
  
  RESULTS
  TFO modified with manganese porphyrin and acridine could bind to the target sequence in a sequence-dependent manner, with a Kd value of 3.5 x 10(-7) mol/L and a relative affinity of 0.008. In the presence of potassium monopersulfate (KHSO(5)), TFO modified with manganese porphyrin and acridine could cleave the target sequence where the triplex DNA was formed.
  
  
  CONCLUSIONS
  In the presence of KHSO(5), TFO modified with manganese porphyrin and acridine could bind and cleave the target HBV-DNA in a sequence-dependent manner.
authors.affiliation: Department of Pediatrics, Xinqiao Hospital, Third Military Medical University, Chongqing 400037, China. yuanfh@mail.tmmu.com.cn
authors.forename: Lixia
authors.initials: L
authors.lastname: Guang
authors.forename: Fahuan
authors.initials: F
authors.lastname: Yuan
authors.forename: Min
authors.initials: M
authors.lastname: Xi
authors.forename: Congmin
authors.initials: C
authors.lastname: Zhao
authors.forename: Li
authors.initials: L
authors.lastname: Liu
authors.forename: Enyi
authors.initials: E
authors.lastname: Wen
authors.forename: Youping
authors.initials: Y
authors.lastname: Ai
mesh_terms: D004247:DNA / Q000187:drug effects / Q000494:pharmacology*; D004279:DNA, Viral / Q000737:chemistry* / Q000187:drug effects; D006515:Hepatitis B virus / Q000235:genetics*; D008345:Manganese / Q000494:pharmacology*; D008665:Metalloporphyrins / Q000494:pharmacology*; D017680:Potassium Compounds / Q000494:pharmacology; D013431:Sulfates / Q000494:pharmacology
chemical_list: D004279:DNA, Viral; D008665:Metalloporphyrins; D017680:Potassium Compounds; D013431:Sulfates; C051802:triplex DNA; D008345:Manganese; C009007:potassium persulfate; D004247:DNA