Quenching of DNA-ethidium fluorescence by amsacrine and other antitumor agents: a possible electron-transfer effect

Baguley, Bruce C.; Bret, Marc Le

doi:10.1021/bi00300a022

Cited by 595 publications

(289 citation statements)

References 25 publications

(43 reference statements)

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“…7). Since we know K~ and n e [9] it follows that the site size np --(3.7 +_ 0.5) and the binding constant Kp = (4.95 + 0.30) × 107 M -I from this experiment. The value of Kp thus calculated is, as noted above, almost certainly an over-estimate of Kp owing to energy transfer from the bound ethidium to 2.…”

Section: Fluorescence Competition Experimentsmentioning

confidence: 82%

“…An assumption in the following analysis is that the concentration of ethidium displaced is directly proportional to the decrease in fluorescence enhancement. In fact this is not the case if energy-transfer between bound ethidium and the displacing ligand occurs, as this causes reduced fluorescence enhancement of bound ethidium [9]. This means that the bound ethidium concentration may be under-estimated and the bound Pt complex 2 concentration over-estimated, leading to an inflated value for K r.…”

Section: Fluorescence Studiesmentioning

confidence: 99%

See 1 more Smart Citation

4‐Picoline‐2,2′:6′,2″‐terpyridine‐platinum(II) — A potent intercalator of DNA

McCoubrey

Latham²,

Cook³

et al. 1996

FEBS Letters

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Section: Fluorescence Competition Experimentsmentioning

confidence: 82%

Section: Fluorescence Studiesmentioning

confidence: 99%

4‐Picoline‐2,2′:6′,2″‐terpyridine‐platinum(II) — A potent intercalator of DNA

McCoubrey

Latham²,

Cook³

et al. 1996

FEBS Letters

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“…1094 Crystal Structure, Supramolecular Self-Assembly and Interaction with DNA of [Mn(sal)(phen) 2 ]ClO 4 of the EB-DNA system fluorescence is usually used to determine the binding strength. 48,49 The fluorescence spectra of EB-DNA system in absence and presence of complex 1 are given in Figure 5b. The fluorescence intensity at 583 nm decreased as a function of the complex concentration, suggesting the displacement of some EB molecules from the base pairs.…”

Section: Fluorescence Titration Experiments For Dna Binding Studiesmentioning

confidence: 99%

Crystal structure, supramolecular self-assembly and interaction with DNA of a mixed ligand manganese(II) complex

Sun¹,

Dong²,

Wang³

et al. 2011

J. Braz. Chem. Soc.

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Um complexo misto de manganês(II), [Mn(sal)(phen) 2 ]ClO 4 (1) (sal = salicilaldeído, phen = 1,10-fenantrolina), foi sintetizado e caracterizado por análise elementar e difração de raio-X de monocristais. A análise dos difratogramas revelou que o complexo 1 cristaliza no grupo espacial monoclínico P2 1 /n. A unidade assimétrica do complexo é composta do cátion complexo [Mn(sal)(phen) 2 ] + e do ânion perclorato não coordenado. O manganês(II) está num ambiente de coordenação MnN 4 O 2 de geometria octaédrica bem distorcida. Quatro tipos de empilhamento p-p envolvendo ligantes fenantrolina e salicilaldeído estão envolvidos na auto-montagem supramolecular. Estas interações de empilhamento aromático cooperam com ligações de hidrogênio para a montagem de uma fascinante arquitetura supramolecular 3D com o complexo. Estudos de espectroscopia de absorção eletrônica e de titulação monitorando-se a fluorescência de 1 com DNA de timo de bezerro sugerem a ligação do complexo por intercalação com uma constante de formação igual a 7,97×10 3 L mol −1 e uma constante de supressão de Stern-Volmer de 1,34×10 4 L mol −1 .A mixed ligand manganese(II) complex, [Mn(sal)(phen) 2 ]ClO 4 (1) (sal = salicylaldehyde, phen = 1,10-phenanthroline), has been synthesized and characterized by elemental analysis and single crystal X-ray diffractometry. The structural analysis revealed that complex 1 crystallizes in the monoclinic space group P2 1 /n. The asymmetric unit of the complex is comprised of [Mn(sal)(phen) 2 ] + complex cation and uncoordinated perchlorate anion. The manganese(II) is located in a seriously distorted octahedral MnN 4 O 2 coordination environment. Four types of p-p stacking modes involving phenanthroline and salicylaldehyde ligands are involved in the supramolecular self-assembly. These aromatic stacking interactions cooperate with hydrogen bonding to assemble the complex into a fascinating 3D supramolecular architecture. Electronic absorption spectroscopy and fluorescence titration studies of the interaction between complex 1 and calf thymus DNA suggest an intercalative binding mode with a constant of 7.97×10 3 L mol −1 and a Stern-Volmer quenching constant of 1.34×10 4 L mol −1 .Keywords: manganese(II) complex, crystal structure, supramolecular self-assembly, DNA interaction, spectrum IntroductionMuch attention has been given to rational design, synthesis and characterization of new transition metal complexes in the past decades because some of them can interact with DNA acting as probes for nucleic acid structure manipulation or exhibiting nuclease property. [1][2][3][4][5] Metal complex can bind to DNA in non-covalent way such as by electrostatic interaction, minor or major groove-bound fashion and intercalation. 6,7 Considerable efforts are yet necessary to develop novel metal complexes binding to DNA through an intercalative association because of their unique properties and applications. [8][9][10][11][12][13] A metallointercalator binds DNA through the insertion of a planar polycyclic aromatic 23 also present int...

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“…Charge transfer by photoinduced reactions between donors and acceptors has provided a useful methodology for exploring the mechanism in DNA (5,6); the donor and acceptor were either noncovalently (7)(8)(9)(10) or covalently (11)(12)(13)(14)(15) bound to DNA. Evidence for long-range oxidative damage was also demonstrated (16)(17)(18)(19).…”

mentioning

confidence: 99%

Femtosecond direct observation of charge transfer between bases in DNA

Wan

Fiebig

Schiemann

et al. 2000

Proc. Natl. Acad. Sci. U.S.A.

363

332

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Charge transfer in supramolecular assemblies of DNA is unique because of the notion that the -stacked bases within the duplex may mediate the transport, possibly leading to damage and͞or repair. The phenomenon of transport through -stacked arrays over a long distance has an analogy to conduction in molecular electronics, but the mechanism still needs to be determined. To decipher the elementary steps and the mechanism, one has to directly measure the dynamics in real time and in suitably designed, structurally well characterized DNA assemblies. Here, we report our first observation of the femtosecond dynamics of charge transport processes occurring between bases within duplex DNA. By monitoring the population of an initially excited 2-aminopurine, an isomer of adenine, we can follow the charge transfer process and measure its rate. We then study the effect of different bases next to the donor (acceptor), the base sequence, and the distance dependence between the donor and acceptor. We find that the charge injection to a nearest neighbor base is crucial and the time scale is vastly different: 10 ps for guanine and up to 512 ps for inosine. Depending on the base sequence the transfer can be slowed down or inhibited, and the distance dependence is dramatic over the range of 14 Å. These observations provide the time scale, and the range and efficiency of the transfer. The results suggest the invalidity of an efficient wire-type behavior and indicate that long-range transport is a slow process of a different mechanism.S ince the first report on conductive (1) one-dimensional DNA crystals more than 30 years ago (2, 3) different methods have been used for the study of conductivity, the latest of which is the measurement of conductance on the mesoscopic scale, which suggests a large band-gap semiconductor behavior (4). Charge transfer by photoinduced reactions between donors and acceptors has provided a useful methodology for exploring the mechanism in DNA (5, 6); the donor and acceptor were either noncovalently (7-10) or covalently (11-15) bound to DNA. Evidence for long-range oxidative damage was also demonstrated (16-19). However, results for different systems have shown different values for the distance range over which the transfer is efficient, in part because of measurements of the yield in most cases.Recently, we have studied DNA with covalently tethered ethidium (hole donor) and a base-like acceptor (7-deazaguanine, Z; ref. 20); the rates and yields reflect the different processes involved. Even though these systems have a covalently tethered hole donor, a careful study of the effects of stacking and distance on charge transfer requires DNA assemblies unperturbed by donor͞acceptor probes. Here, we report such studies in DNA assemblies with the donor and acceptor being nucleic acid bases (Fig. 1). These systems are unique because (i) there are only minor structural perturbations arising; (ii) no ambiguities occur with respect to distance separating donors and acceptors; (iii) the assemblies are structurally wel...

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Quenching of DNA-ethidium fluorescence by amsacrine and other antitumor agents: a possible electron-transfer effect

Cited by 595 publications

References 25 publications

4‐Picoline‐2,2′:6′,2″‐terpyridine‐platinum(II) — A potent intercalator of DNA

4‐Picoline‐2,2′:6′,2″‐terpyridine‐platinum(II) — A potent intercalator of DNA

Crystal structure, supramolecular self-assembly and interaction with DNA of a mixed ligand manganese(II) complex

Femtosecond direct observation of charge transfer between bases in DNA

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