TY - JOUR
T1 - Competitive formation of both long-range 5′-5′ and short-range antiparallel 3′-3′ DNA interstrand cross-links by a trinuclear platinum complex on binding to a 10-mer duplex
AU - Ruhayel, R.A.
AU - Berners-Price, Susan
AU - Farrell, N.P.
PY - 2013
Y1 - 2013
N2 - 2D [1H, 15N] HSQC NMR spectroscopy has been used to monitor the reaction of fully 15N-labelled [{trans-PtCl(NH 3)2}2(μ-trans-Pt(NH3) 2{NH2(CH2)6NH2} 2)]4+ (Triplatin, BBR3464 or 1,0,1/t,t,t ( 15N-1)) with the self-complementary 10-mer DNA duplex 5′-{d(ACGTATACGT)2} (duplex I) at pH 5.4 and 298 K. Initial electrostatic interactions were observed in the minor groove of the duplex, followed directly by aquation to form the monoaqua monochloro species. There was evidence for two discrete monofunctional adducts, through covalent binding at the guanine N7 sites, and one had distinctly different 1H/ 15N chemical shifts to those observed previously in analogous reactions. Bifunctional adduct formation followed by binding at a second guanine N7 site with evidence for both the 3′-3′ 1,2-GG and 5′-5′ 1,6-GG interstrand cross-links in a ratio of 2:1. The results show that cross-link preference is kinetically controlled and will depend critically on the reaction conditions, explaining why in a previous reaction of 1 with duplex I the major adduct isolated by HPLC had two simultaneous 3′-3′ 1,2-interstrand cross-links. © 2013 The Royal Society of Chemistry.
AB - 2D [1H, 15N] HSQC NMR spectroscopy has been used to monitor the reaction of fully 15N-labelled [{trans-PtCl(NH 3)2}2(μ-trans-Pt(NH3) 2{NH2(CH2)6NH2} 2)]4+ (Triplatin, BBR3464 or 1,0,1/t,t,t ( 15N-1)) with the self-complementary 10-mer DNA duplex 5′-{d(ACGTATACGT)2} (duplex I) at pH 5.4 and 298 K. Initial electrostatic interactions were observed in the minor groove of the duplex, followed directly by aquation to form the monoaqua monochloro species. There was evidence for two discrete monofunctional adducts, through covalent binding at the guanine N7 sites, and one had distinctly different 1H/ 15N chemical shifts to those observed previously in analogous reactions. Bifunctional adduct formation followed by binding at a second guanine N7 site with evidence for both the 3′-3′ 1,2-GG and 5′-5′ 1,6-GG interstrand cross-links in a ratio of 2:1. The results show that cross-link preference is kinetically controlled and will depend critically on the reaction conditions, explaining why in a previous reaction of 1 with duplex I the major adduct isolated by HPLC had two simultaneous 3′-3′ 1,2-interstrand cross-links. © 2013 The Royal Society of Chemistry.
U2 - 10.1039/c2dt32079g
DO - 10.1039/c2dt32079g
M3 - Article
C2 - 23165925
SN - 1477-9226
VL - 42
SP - 3181
EP - 3187
JO - Dalton Transactions: an international journal of inorganic chemistry
JF - Dalton Transactions: an international journal of inorganic chemistry
IS - 9
ER -