title: Mono-, di- and trimeric binding of a bis-netropsin to DNA.
abstract: An unusual 3:1 stoichiometry for complex formation between an elongated bis-netropsin compound and its binding site on DNA has been observed. Circular dichroism measurements distinguish two types of complexes formed between this bis-netropsin and poly[d(A-T)].poly[d(A-T)]. The first type is characterized by a 1:1 saturating ratio of bound molecules per ten base pairs. Formation of the second type results from the cooperative binding of two additional bis-netropsin molecules to the first type of complex. In contrast to these results observed for binding to the alternating polynucleotide, only the 1:1 type of complex is formed when this ligand binds to the homopolymer poly(dA).poly(dT).
mesh_terms: D002942:Circular Dichroism; D004247:DNA / Q000737:chemistry*; D007700:Kinetics; D009429:Netropsin / Q000031:analogs & derivatives* / Q000737:chemistry; D009690:Nucleic Acid Conformation; D011067:Poly dA-dT / Q000737:chemistry*
chemical_list: D011067:Poly dA-dT; D009429:Netropsin; C032161:bis-netropsin; D004247:DNA