title: [Sequence-dependent cleavage of HBV DNA by combining with triple helix-forming oligodeoxyribonucleotides modified with manganese porphyrin in vitro].
abstract: OBJECTIVE
  To observe the ability of triple helix-forming oligonucleotides (TFO) modified with manganese porphyrin to combine with and cleave HBV DNA fractions.
  
  
  METHODS
  The ends of TFO were modified with manganese porphyrin and acridine; At 37 degrees C and pH 7.4 condition in vitro, TFO modified with manganese porphyrin and acridine were bound with 32P labeled HBV DNA fragments, the affinity and specificity binding to target sequence were tested by electrophoretic mobility shift and DNase 1 footprinting assays, the ability to cleave HBV DNA fractions was observed with cleavage experiments.
  
  
  RESULTS
  TFO modified with manganese porphyrin and acridine could bind to target sequence in a sequence-dependent manner with Kd values of 3.5 x 10(-7) mol/L and a relative affinity of 0.008. In the presence of KHSO5, TFO modified with manganese porphyrin and acridine could cleave target sequence in the region forming triple DNA.
  
  
  CONCLUSIONS
  In the presence of KHSO5, TFO modified with manganese porphyrin and acridine could cleave target HBV-DNA in sequence-dependent manner.
authors.affiliation: Department of Pediatrics, Xinqiao Hospital, Third Military Medical University, Chongqing 400037, China.
authors.forename: Li-xia
authors.initials: LX
authors.lastname: Guang
authors.forename: Fa-huan
authors.initials: FH
authors.lastname: Yuan
authors.forename: Min
authors.initials: M
authors.lastname: Xi
authors.forename: Cong-min
authors.initials: CM
authors.lastname: Zhao
authors.forename: Li
authors.initials: L
authors.lastname: Liu
authors.forename: En-yi
authors.initials: EY
authors.lastname: Wen
authors.forename: You-ping
authors.initials: YP
authors.lastname: Ai
mesh_terms: D001667:Binding, Competitive; D016172:DNA Fingerprinting; D003850:Deoxyribonuclease I / Q000378:metabolism; D024202:Electrophoretic Mobility Shift Assay; D006515:Hepatitis B virus / Q000235:genetics*; D008345:Manganese / Q000737:chemistry; D008665:Metalloporphyrins / Q000737:chemistry*; D009690:Nucleic Acid Conformation; D009838:Oligodeoxyribonucleotides / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism
chemical_list: D008665:Metalloporphyrins; D009838:Oligodeoxyribonucleotides; D008345:Manganese; D003850:Deoxyribonuclease I