Peer-Reviewed Journal Details
Mandatory Fields
Prisecaru A.;Molphy Z.;Kipping R.;Peterson E.;Qu Y.;Kellett A.;Farrell N.
2014
December
Nucleic Acids Research
The phosphate clamp: Sequence selective nucleic acid binding profiles and conformational induction of endonuclease inhibition by cationic Triplatin complexes
Published
30 ()
Optional Fields
42
22
13474
13487
© The Author(s) 2014. Published by Oxford University Press on behalf of Nucleic Acids Research. The substitution-inert polynuclear platinum(II) complex (PPC) series, [{trans-Pt(NH3)2(NH2(CH2)nNH3)}2-μ-(trans-Pt(NH3)2(NH2(CH2)nNH2)2}](NO3)8, where n = 5 (AH78P), 6 (AH78 TriplatinNC) and 7 (AH78H), are potent non-covalent DNA binding agents where nucleic acid recognition is achieved through use of the 'phosphate clamp' where the square-planar tetraam(m)ine Pt(II) coordination units all form bidentate N-O-N complexes through hydrogen bonding with phosphate oxygens. The modular nature of PPC-DNA interactions results in high affinity for calf thymus DNA (Kapp ∼5 × 107 M-1). The phosphate clamp-DNA interactions result in condensation of superhelical and B-DNA, displacement of intercalated ethidium bromide and facilitate cooperative binding of Hoechst 33258 at the minor groove. The effect of linker chain length on DNA conformational changes was examined and the pentane-bridged complex, AH78P, was optimal for condensing DNA with results in the nanomolar region. Analysis of binding affinity and conformational changes for sequence-specific oligonucleotides by ITC, dialysis, ICP-MS, CD and 2D-1H NMR experiments indicate that two limiting modes of phosphate clamp binding can be distinguished through their conformational changes and strongly suggest that DNA condensation is driven by minorgroove spanning. Triplatin-DNA binding prevents endonuclease activity by type II restriction enzymes BamHI, EcoRI and SalI, and inhibition was confirmed through the development of an on-chip microfluidic protocol.
0305-1048
10.1093/nar/gku1157
Grant Details