TY - JOUR
T1 - 1H NMR Studies of Nickel(II) Complexes Bound to Oligonucleotides
T2 - A Novel Technique for Distinguishing the Binding Locations of Metal Complexes in DNA
AU - Bhattacharya, Pratip K.
AU - Lawson, Holly J.
AU - Barton, Jacqueline K.
PY - 2003/12/29
Y1 - 2003/12/29
N2 - The selective paramagnetic relaxation of oligonucleotide proton resonances of d(GTCGAC)2 and d(GTGCAC)2 by Ni(phen) 2(L)2+ where L = dipyridophenazine (dppz), dipyrido[3,2-d:2′,3′-f]quinoxaline (dpq), and phenanthrenequinone (phi) has been examined to obtain structural insight into the noncovalent binding of these metal complexes to DNA. In the oligonucleotide d(GTCGAC) 2, preferential broadening of the G1H8, G4H8, T2H6, and C3H6 proton resonances was observed with Ni(phen)2(dppz)2+, Ni(phen)2(dpq)2+, and Ni(phen)2(phi) 2+. In the case of the sequence d(GTGCAC)2, where the central two bases are juxtaposed from the previous one, preferential broadening was observed instead for the A5H2 proton resonance. Thus, a subtle change in the sequence of the oligonucleotide can cause significant change in the binding location of the metal complex in the oligonucleotide. Owing to comparable changes for all metal complexes and sequences in broadening of the thymine methyl proton resonances, we attribute the switch in preferential broadening to a change in site location within the oligomer rather than to an alteration of groove location. Therefore, even for DNA-binding complexes of low sequence-specificity, distinct variations in binding as a function of sequence are apparent.
AB - The selective paramagnetic relaxation of oligonucleotide proton resonances of d(GTCGAC)2 and d(GTGCAC)2 by Ni(phen) 2(L)2+ where L = dipyridophenazine (dppz), dipyrido[3,2-d:2′,3′-f]quinoxaline (dpq), and phenanthrenequinone (phi) has been examined to obtain structural insight into the noncovalent binding of these metal complexes to DNA. In the oligonucleotide d(GTCGAC) 2, preferential broadening of the G1H8, G4H8, T2H6, and C3H6 proton resonances was observed with Ni(phen)2(dppz)2+, Ni(phen)2(dpq)2+, and Ni(phen)2(phi) 2+. In the case of the sequence d(GTGCAC)2, where the central two bases are juxtaposed from the previous one, preferential broadening was observed instead for the A5H2 proton resonance. Thus, a subtle change in the sequence of the oligonucleotide can cause significant change in the binding location of the metal complex in the oligonucleotide. Owing to comparable changes for all metal complexes and sequences in broadening of the thymine methyl proton resonances, we attribute the switch in preferential broadening to a change in site location within the oligomer rather than to an alteration of groove location. Therefore, even for DNA-binding complexes of low sequence-specificity, distinct variations in binding as a function of sequence are apparent.
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U2 - 10.1021/ic0348291
DO - 10.1021/ic0348291
M3 - Article
C2 - 14686861
AN - SCOPUS:0348223844
SN - 0020-1669
VL - 42
SP - 8811
EP - 8817
JO - Inorganic Chemistry
JF - Inorganic Chemistry
IS - 26
ER -