51
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Chattopadhyay B, Mukherjee M. Molecular dynamics study and electronic structure evolution of a DNA duplex d(CCCGATCGGG)2. J Phys Chem B 2011; 115:1760-6. [PMID: 21291265 DOI: 10.1021/jp109779v] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The molecular dynamics simulations and electronic structure evolution of a A-DNA decamer, d(CCCGATCGGG)(2), in the presence and absence of [Co(NH(3))(6)](3+) ions have been investigated. In both cases, the results of 2.5 ns MD simulation indicate a A-DNA→B-DNA transition. Ab initio DFT calculations were performed on a series of conformations representing the A→B transitions to reveal the dynamical behavior of the electronic structure of the decamer. The results suggest that the conformational parameters as well as the surrounding environment have no direct correlation with the electronic structures. Instead, the thermal fluctuations play an important role in the electronic structure of the present DNA system.
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Affiliation(s)
- Basab Chattopadhyay
- Department of Solid State Physics, Indian Association for the Cultivation of Science, Kolkata 700032, India
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52
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Mehrgardi MA, Daneshtalab R. Electrochemical detection of different types of single-base mismatches in DNA using copper-phthalocyanine tetrasulfonic acid. J Electroanal Chem (Lausanne) 2011. [DOI: 10.1016/j.jelechem.2010.10.001] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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53
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Kumar A, Sevilla MD. Proton-coupled electron transfer in DNA on formation of radiation-produced ion radicals. Chem Rev 2010; 110:7002-23. [PMID: 20443634 PMCID: PMC2947616 DOI: 10.1021/cr100023g] [Citation(s) in RCA: 154] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Affiliation(s)
- Anil Kumar
- Department of Chemistry, Oakland University, Rochester, MI 48309
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54
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55
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Pitterl F, Chervet JP, Oberacher H. Electrochemical simulation of oxidation processes involving nucleic acids monitored with electrospray ionization-mass spectrometry. Anal Bioanal Chem 2010; 397:1203-15. [PMID: 20393841 DOI: 10.1007/s00216-010-3674-z] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2010] [Revised: 03/18/2010] [Accepted: 03/21/2010] [Indexed: 02/03/2023]
Abstract
Oxidation is commonly involved in the alteration of nucleic acids giving rise to diverse effects including mutation, cell death, malignancy, and aging. We demonstrate that electrochemistry represents an efficient and fast method to mimic oxidative modification of nucleic acids occurring in biological systems. Oxidation reactions were performed in a thin-layer cell employing a conductive diamond electrode as the working electrode and were monitored with electrospray ionization-mass spectrometry. Mass voltammograms were acquired for guanosine, adenosine, cytidine, and uridine. The observed oxidation potentials increased in the order guanosine << adenosine < cytidine < uridine. Oxidation products of guanosine were characterized using high-resolution (tandem) mass spectrometry performed with a quadrupole-quadrupole time-of-flight instrument. On the basis of these experiments, it was concluded that the initial electrode reaction involves a one-electron, one-proton step to give a free radical. The primary oxidation product represents the starting point for a number of follow-up reactions, including guanosine dimerization as well as further oxidation to 8-hydroxyguanosine. Similar results were obtained for guanosine monophosphate and the corresponding dinucleotide. Furthermore, the guanosine radical was identified as an important intermediate for the formation of a covalent adduct with acetaminophen. This observation sheds new light on the mechanism of adduct formation as it demonstrates that oxidative activation of both the nucleobase and the adduct-forming agent is necessary to observe a detectable amount of adduct species.
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Affiliation(s)
- Florian Pitterl
- Institute of Legal Medicine, Innsbruck Medical University, Muellerstrasse 44, 6020 Innsbruck, Austria
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56
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Siegbahn PEM, Blomberg MRA. Quantum Chemical Studies of Proton-Coupled Electron Transfer in Metalloenzymes. Chem Rev 2010; 110:7040-61. [DOI: 10.1021/cr100070p] [Citation(s) in RCA: 169] [Impact Index Per Article: 12.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Affiliation(s)
- Per E. M. Siegbahn
- Department of Physics, AlbaNova University Center and Department of Biochemistry and Biophysics, Arrhenius Laboratory, Stockholm University, SE-106 91, Stockholm, Sweden
| | - Margareta R. A. Blomberg
- Department of Physics, AlbaNova University Center and Department of Biochemistry and Biophysics, Arrhenius Laboratory, Stockholm University, SE-106 91, Stockholm, Sweden
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57
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Leung EKY, Sen D. The use of charge flow and quenching (CFQ) to probe nucleic acid folds and folding. Methods 2010; 52:141-9. [PMID: 20554046 DOI: 10.1016/j.ymeth.2010.06.006] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2010] [Indexed: 12/12/2022] Open
Abstract
Charge flow and quenching ("CFQ") is a relatively new, versatile, and easily carried out methodology for probing a number of unique features of DNA and RNA folded structures, and of their folding pathways. An electrical charge (an electron hole, or radical cation) is injected site-specifically into the end of a pre-determined reference helix within the larger DNA or RNA structure. The fate of the injected charge, as it percolates through the folded DNA or RNA is then monitored by mapping the oxidative consequences of the charge flow. Some of the kinds of structural and folding information that can be obtained from CFQ experiments include: a quantitative measure of helix-helix connectivity; the dynamics of specific bases; folding and unfolding pathways; the mapping of unusual, conformation-dependent, electronic properties of individual bases; extents of solvent exposure and susceptibility to quenching from the solvent. CFQ is a relatively new methodology, and is applicable to DNA and RNA structures and folds. In the near future it is expected that the range of applications of this methodology will increase dramatically.
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Affiliation(s)
- Edward K Y Leung
- Department of Biochemistry & Molecular Biology, The University of Chicago, Chicago, IL 60637, USA.
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58
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Jang KJ, Yeo GY, Cho TS, Eom GH, Kim C, Kim SK. Real-time detection of DNA cleavage induced by [M(2,2′-dipyridylamine)2(NO3)n]x+ (M=Cd, Cu, Ni, Zn, n=1,2, x=0,1): Effect of central metal ions. Biophys Chem 2010; 148:138-43. [DOI: 10.1016/j.bpc.2010.03.009] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2010] [Revised: 03/10/2010] [Accepted: 03/11/2010] [Indexed: 10/19/2022]
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59
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Ndlebe T, Panyutin I, Neumann R. Analysis of the contribution of charge transport in iodine-125-induced DNA damage. Radiat Res 2010; 173:98-109. [PMID: 20041764 DOI: 10.1667/rr1865.1] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
Auger electron emitters like (125)I are the radionuclides of choice for gene-targeted radiotherapy. The highly localized damage they induce in DNA is produced by three mechanisms: direct damage by the emitted Auger electrons, indirect damage by diffusible free radicals produced by Auger electrons traveling in water, and charge neutralization of the residual, highly positively charged tellurium daughter atom by stripping electrons from covalent bonds of neighboring residues. The purpose of our work was to determine whether these mechanisms proceed through an intermediate energy transfer step along DNA. It was proposed that this intermediate step proceeds through the charge transport mechanism in DNA. Conventional charge transport has been described as either a hopping mechanism initiated by charge injection into DNA and propagated by charge migration along the DNA or a tunneling mechanism in which charge moves directly from a donor to an acceptor within DNA. Well-known barriers for the hopping mechanism were used to probe the role of charge transport in (125)I-induced DNA damage. We studied their effect on the distribution of DNA breaks produced by the decay of (125)I in samples frozen at -80 degrees C. We found that these barriers had no measurable effect on the distribution of (125)I-induced breaks.
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Affiliation(s)
- Thabisile Ndlebe
- Radiology and Imaging Sciences, Clinical Center, NIH, Bethesda, Maryland 20892, USA
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60
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Prunkl C, Berndl S, Wanninger-Weiß C, Barbaric J, Wagenknecht HA. Photoinduced short-range electron transfer in DNA with fluorescent DNA bases: lessons from ethidium and thiazole orange as charge donors. Phys Chem Chem Phys 2010; 12:32-43. [DOI: 10.1039/b914487k] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
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61
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Yang H, Rys A, McLaughlin C, Sleiman H. Templated Ligand Environments for the Selective Incorporation of Different Metals into DNA. Angew Chem Int Ed Engl 2009; 48:9919-23. [DOI: 10.1002/anie.200904186] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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62
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Wang Y, Li J, Liu Y, Ma R, Jia W, Cui H, Wang H. Fabrication of the DNA/poly(3-methylthiophene) composite film modified electrode and its application for the study on the voltammetric behavior and determination of 8-hydroxy-2′-deoxyguanosine. ACTA ACUST UNITED AC 2009. [DOI: 10.1007/s11426-009-0241-6] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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63
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Yang H, Rys A, McLaughlin C, Sleiman H. Templated Ligand Environments for the Selective Incorporation of Different Metals into DNA. Angew Chem Int Ed Engl 2009. [DOI: 10.1002/ange.200904186] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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64
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Yan CF, Jiang FL, Chen L, Feng R, Yang M, Hong MC. The d10 metal-sulfosalicylate complexes: Herring-bone, ladder and double-stranded chain frameworks with green luminescences. J SOLID STATE CHEM 2009. [DOI: 10.1016/j.jssc.2009.08.025] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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65
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Wachholz F, Duwensee H, Schmidt R, Zwanzig M, Gimsa J, Fiedler S, Flechsig GU. Template-Free Galvanic Nanostructuring of Gold Electrodes for Sensitive Electrochemical Biosensors. ELECTROANAL 2009. [DOI: 10.1002/elan.200904665] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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66
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Triberis GP, Dimakogianni M. Field and temperature dependence of the small polaron hopping electrical conductivity in 1D disordered systems. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2009; 21:385406. [PMID: 21832371 DOI: 10.1088/0953-8984/21/38/385406] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
We investigate the effect of the electric field and the temperature on the electrical conductivity of one-dimensional disordered systems due to phonon assisted hopping of small polarons. The microscopic transport mechanism is treated within the framework of the generalized molecular crystal model and the Kubo formula, while percolation theoretical arguments lead to analytical expressions for the macroscopic behavior of the electrical conductivity at high (multi-phonon assisted hopping) and low (few-phonon assisted hopping) temperatures under the influence of moderate electric fields. The theoretical results are successfully applied to recent experimental findings for a wide temperature range and from low up to moderate electric fields. Comparison is made with other theories.
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67
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Jin B, Min KS, Han SW, Kim SK. DNA-binding geometry dependent energy transfer from 4′,6-diamidino-2-phenylindole to cationic porphyrins. Biophys Chem 2009; 144:38-45. [DOI: 10.1016/j.bpc.2009.06.003] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2009] [Revised: 06/06/2009] [Accepted: 06/09/2009] [Indexed: 10/20/2022]
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68
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Woiczikowski PB, Kubar T, Gutiérrez R, Caetano RA, Cuniberti G, Elstner M. Combined density functional theory and Landauer approach for hole transfer in DNA along classical molecular dynamics trajectories. J Chem Phys 2009; 130:215104. [PMID: 19508103 DOI: 10.1063/1.3146905] [Citation(s) in RCA: 73] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
We investigate in detail the charge transport characteristics of DNA wires with various sequences and lengths in the presence of solvent. Our approach combines large-scale quantum/classical molecular dynamics (MD) simulations with transport calculations based on Landauer theory. The quantum mechanical transmission function of the wire is calculated along MD trajectories and thus encodes the influence of dynamical disorder arising from the environment (water, backbone, counterions) and from the internal base dynamics. We show that the correlated fluctuations of the base pair dynamics are crucial in determining the transport properties of the wire and that the effect of fluctuations can be quite different for sequences with low and high static disorders (differences in base ionization potentials). As a result, in structures with high static disorder as is the case of the studied Dickerson dodecamer, the weight of high-transmissive structures increases due to dynamical fluctuations and so does the calculated average transmission. Our analysis further supports the basic intuition of charge-transfer active conformations as proposed by Barton et al. [J. Am. Chem. Soc. 126, 11471 (2004)]. However, not DNA conformations with good stacking contacts leading to large interbase hopping values are necessarily the most important, but rather those where the average fluctuation of ionization potentials along the base stack is small. The reason behind this is that the ensemble of conformations leads to average electronic couplings, which are large enough for sufficient transmission. On the other hand, the alignment of onsite energies is the critical parameter which gates the charge transport.
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Affiliation(s)
- P Benjamin Woiczikowski
- Department of Physical and Theoretical Chemistry, Technische Universitat Braunschweig, D-38106 Braunschweig, Germany
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69
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González-Ramírez I, Climent T, Serrano-Pérez JJ, González-Luque R, Merchán M, Serrano-Andrés L. The role of pyrimidine nucleobase excimers in DNA photophysics and photoreactivity. PURE APPL CHEM 2009. [DOI: 10.1351/pac-con-08-08-31] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Quantum chemical studies using the accurate CASPT2//CASSCF procedure show that π-stacked interactions in biochromophores such as pyrimidine (Pyr) DNA/RNA nucleobases pairs yield excimer-like situations which behave as precursors of processes like charge transfer (CT) or photoreactivity and are the source of the emissive properties in DNA. Examples are the CT between adjacent DNA nucleobases in a strand of oligonucleotides and the photodimerization taking place in cytosine (C) pairs leading to cyclobutanecytosine (CBC) mutants. These processes take place through nonadiabatic photochemical mechanisms whose evolution is determined by the presence and accessibility of conical intersections (CIs) and other surface crossings between different electronic states.
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Affiliation(s)
- Israel González-Ramírez
- 1Instituto de Ciencia Molecular, Universitat de València, Apartado de Correos 22085, ES-46071 Valencia, Spain
| | - Teresa Climent
- 1Instituto de Ciencia Molecular, Universitat de València, Apartado de Correos 22085, ES-46071 Valencia, Spain
| | - Juan José Serrano-Pérez
- 1Instituto de Ciencia Molecular, Universitat de València, Apartado de Correos 22085, ES-46071 Valencia, Spain
| | - Remedios González-Luque
- 1Instituto de Ciencia Molecular, Universitat de València, Apartado de Correos 22085, ES-46071 Valencia, Spain
| | - Manuela Merchán
- 1Instituto de Ciencia Molecular, Universitat de València, Apartado de Correos 22085, ES-46071 Valencia, Spain
| | - Luis Serrano-Andrés
- 1Instituto de Ciencia Molecular, Universitat de València, Apartado de Correos 22085, ES-46071 Valencia, Spain
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70
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Selective accumulation of harmful compounds by the DNA-inorganic hybrid-immobilized glass bead. Anal Chim Acta 2009; 647:249-54. [DOI: 10.1016/j.aca.2009.06.024] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2009] [Revised: 06/05/2009] [Accepted: 06/10/2009] [Indexed: 11/23/2022]
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71
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Duwensee H, Mix M, Broer I, Flechsig GU. Electrochemical detection of modified maize gene sequences by multiplexed labeling with osmium tetroxide bipyridine. Electrochem commun 2009. [DOI: 10.1016/j.elecom.2009.05.037] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
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72
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KAUR INDERPREET, KULKARNI GIRISHS, AJORE RAM, BHARADWAJ RICHA, KOTAMARTHI BHANUPRAKASH, SINGH NIMAL, BHARADWAJ LALITM. ROLE OF ADENINE AND GUANINE SITES IN HOLE HOPPING IN DNA NANOWIRE. JOURNAL OF THEORETICAL & COMPUTATIONAL CHEMISTRY 2009. [DOI: 10.1142/s0219633609004873] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Transfer integrals for oligos with different bases have been calculated using INDO/Koopman's approximation to unveil the charge transport mechanism in DNA. The sequences, G(A) n G , n = 1, 2, …, 10; G(A) x G(A) y G , x + y = 9; and G(A) x G(A) y G(A) z G , x + y + z = 8, were employed to interpret the Guanine (G) and Adenine(A) hopping. Adenine hopping is found to be faster in G(A) n G sequences with longer Adenine bridges (n ≥ 3). Inserting G-bases in between G(A) 10 G led to a decrease in the value of transfer integrals. Close analysis has revealed that bridge closer to 3′-end forms a hopping bottleneck; however, the presence of bridge at 5′-end enhances the charge transfer through A-hopping. Further insertion of single G sites in G(A) x G(A) y G (where x + y = 9) reduces the transfer integrals, thus explaining the hampering of A-hopping. Hence, sequences of the type G(A) n G , n > 3, are better suited for their application as molecular wire. Finally, studies on the effect of flipping of bases, i.e. flipping G:C to C:G on transfer integrals, have revealed that helical distortions and conformational changes due to sequence variations lead to changes in coupling, which is highly unpredictable.
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Affiliation(s)
- INDERPREET KAUR
- Biomolecular Electronics and Nanotechnology Division (BEND), Central Scientific Instruments Organization (CSIO), Sector-30C, Chandigarh, India
| | - GIRISH S. KULKARNI
- Biomolecular Electronics and Nanotechnology Division (BEND), Central Scientific Instruments Organization (CSIO), Sector-30C, Chandigarh, India
| | - RAM AJORE
- Biomolecular Electronics and Nanotechnology Division (BEND), Central Scientific Instruments Organization (CSIO), Sector-30C, Chandigarh, India
| | - RICHA BHARADWAJ
- Biomolecular Electronics and Nanotechnology Division (BEND), Central Scientific Instruments Organization (CSIO), Sector-30C, Chandigarh, India
| | | | - NIMAL SINGH
- Department of Physics, Panjab University, Sector-14, Chandigarh, India
| | - LALIT M. BHARADWAJ
- Biomolecular Electronics and Nanotechnology Division (BEND), Central Scientific Instruments Organization (CSIO), Sector-30C, Chandigarh, India
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73
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Cagnin S, Caraballo M, Guiducci C, Martini P, Ross M, SantaAna M, Danley D, West T, Lanfranchi G. Overview of electrochemical DNA biosensors: new approaches to detect the expression of life. SENSORS (BASEL, SWITZERLAND) 2009; 9:3122-48. [PMID: 22574066 PMCID: PMC3348825 DOI: 10.3390/s90403122] [Citation(s) in RCA: 77] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/18/2009] [Revised: 04/20/2009] [Accepted: 04/23/2009] [Indexed: 12/25/2022]
Abstract
DNA microarrays are an important tool with a variety of applications in gene expression studies, genotyping, pharmacogenomics, pathogen classification, drug discovery, sequencing and molecular diagnostics. They are having a strong impact in medical diagnostics for cancer, toxicology and infectious disease applications. A series of papers have been published describing DNA biochips as alternative to conventional microarray platforms to facilitate and ameliorate the signal readout. In this review, we will consider the different methods proposed for biochip construction, focusing on electrochemical detection of DNA. We also introduce a novel single-stranded DNA platform performing high-throughput SNP detection and gene expression profiling.
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Affiliation(s)
- Stefano Cagnin
- CRIBI Biotechnology Centre and Department of Biology, University of Padova, via U. Bassi 58/B 35121 Padova, Italy; E-Mails: ;
| | - Marcelo Caraballo
- CombiMatrix Corporation, 6500 Harbour Heights Pkwy, 301, Mukilteo, WA 98275, USA; E-Mails: ; ; ; ;
| | - Carlotta Guiducci
- DEIS Dipartimento di Elettronica, Informatica e Sistemistica, University of Bologna, Viale Risorgimento 2, 40136 Bologna, Italy; E-Mail:
- IBI-EPFL, Institute of Bioengineering, Ecole Polytechnique Federale de Lausanne, Station 15 CH-1015 Lausanne, Switzerland
| | - Paolo Martini
- CRIBI Biotechnology Centre and Department of Biology, University of Padova, via U. Bassi 58/B 35121 Padova, Italy; E-Mails: ;
| | - Marty Ross
- CombiMatrix Corporation, 6500 Harbour Heights Pkwy, 301, Mukilteo, WA 98275, USA; E-Mails: ; ; ; ;
| | - Mark SantaAna
- CombiMatrix Corporation, 6500 Harbour Heights Pkwy, 301, Mukilteo, WA 98275, USA; E-Mails: ; ; ; ;
| | - David Danley
- CombiMatrix Corporation, 6500 Harbour Heights Pkwy, 301, Mukilteo, WA 98275, USA; E-Mails: ; ; ; ;
| | - Todd West
- CombiMatrix Corporation, 6500 Harbour Heights Pkwy, 301, Mukilteo, WA 98275, USA; E-Mails: ; ; ; ;
| | - Gerolamo Lanfranchi
- CRIBI Biotechnology Centre and Department of Biology, University of Padova, via U. Bassi 58/B 35121 Padova, Italy; E-Mails: ;
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74
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Pseudo-cyclic Face-to-face Rigid Structure Caused by the Intramolecular Ion Pair Effect. Molecules 2009; 14:1546-60. [PMID: 19384284 PMCID: PMC6254276 DOI: 10.3390/molecules14041546] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2009] [Revised: 04/09/2009] [Accepted: 04/10/2009] [Indexed: 11/17/2022] Open
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75
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Ito T, Hayashi A, Kondo A, Uchida T, Tanabe K, Yamada H, Nishimoto SI. DNA hairpins containing a diaminostilbene derivative as a photoinduced electron donor for probing the effects of single-base mismatches on excess electron transfer in DNA. Org Lett 2009; 11:927-30. [PMID: 19170616 DOI: 10.1021/ol802896y] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
To investigate the effects of local structural disorder induced by a single-base mismatch on excess electron transfer (EET) in DNA, a novel hairpin DNA containing diaminostilbene (DAS) as a photoinducible electron donor has been developed. It was clearly demonstrated that EET efficiency depends on the electron injection modes from the electron donors and redox properties of the mismatched bases.
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Affiliation(s)
- Takeo Ito
- Department of Energy and Hydrocarbon Chemistry, Graduate School of Engineering, Kyoto University, Kyoto 615-8510, Japan.
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76
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Abstract
The base pair stack of DNA has been demonstrated as a medium for long-range charge transport chemistry both in solution and at DNA-modified surfaces. This chemistry is exquisitely sensitive to structural perturbations in the base pair stack as occur with lesions, single base mismatches, and protein binding. We have exploited this sensitivity for the development of reliable electrochemical assays based on DNA charge transport at self-assembled DNA monolayers. Here, we discuss the characteristic features, applications, and advantages of DNA-mediated electrochemistry.
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Affiliation(s)
- Alon A Gorodetsky
- Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, California 91125, USA
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77
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Evtyugin GA, Budnikov GK, Porfir’eva AV. Electrochemical DNA-sensors for determining biologically active low-molecular compounds. RUSS J GEN CHEM+ 2009. [DOI: 10.1134/s107036320812030x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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78
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Triberis GP, Dimakogianni M. Correlated small polaron hopping transport in 1D disordered systems at high temperatures: a possible charge transport mechanism in DNA. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2009; 21:035114. [PMID: 21817272 DOI: 10.1088/0953-8984/21/3/035114] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
Based on the generalized molecular crystal model (GMCM) and theoretical percolation arguments we investigate small polaron hopping transport in 1D disordered systems at high temperatures. Correlation (cr) effects are taken into account. An analytical expression for the temperature dependence of the electrical conductivity, lnσ(h,cr)∼T(-1/2), is obtained. This result reproduces satisfactorily the experimental data reported for λ-DNA and for poly(dA)-poly(dT) DNA, considering DNA as a one-dimensional disordered molecular wire in which small polarons are the charge carriers. lnσ(h,cr) versus T(-1/2) plots permit the evaluation of the maximum hopping distance. The results indicate that correlation effects are probably responsible for large hopping distances in DNA samples.
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79
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Gorodetsky AA, Hammond WJ, Hill MG, Slowinski K, Barton JK. Scanning electrochemical microscopy of DNA monolayers modified with Nile Blue. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2008; 24:14282-14288. [PMID: 19053641 PMCID: PMC2668266 DOI: 10.1021/la8029243] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
Scanning electrochemical microscopy (SECM) is used to probe long-range charge transport (CT) through DNA monolayers containing the redox-active Nile Blue (NB) intercalator covalently affixed at a specific location in the DNA film. At substrate potentials negative of the formal potential of covalently attached NB, the electrocatalytic reduction of Fe(CN)6(3-) generated at the SECM tip is observed only when NB is located at the DNA/solution interface; for DNA films containing NB in close proximity to the DNA/electrode interface, the electrocatalytic effect is absent. This behavior is consistent with both rapid DNA-mediated CT between the NB intercalator and the gold electrode as well as a rate-limiting electron transfer between NB and the solution phase Fe(CN)6(3-). The DNA-mediated nature of the catalytic cycle is confirmed through sequence-specific and localized detection of attomoles of TATA-binding protein, a transcription factor that severely distorts DNA upon binding. Importantly, the strategy outlined here is general and allows for the local investigation of the surface characteristics of DNA monolayers both in the absence and in the presence of DNA binding proteins. These experiments highlight the utility of DNA-modified electrodes as versatile platforms for SECM detection schemes that take advantage of CT mediated by the DNA base pair stack.
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80
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Huska D, Hubalek J, Adam V, Kizek R. Miniaturized electrochemical detector as a tool for detection of DNA amplified by PCR. Electrophoresis 2008; 29:4964-71. [DOI: 10.1002/elps.200800445] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
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81
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Lukacs A, Eker APM, Byrdin M, Brettel K, Vos MH. Electron hopping through the 15 A triple tryptophan molecular wire in DNA photolyase occurs within 30 ps. J Am Chem Soc 2008; 130:14394-5. [PMID: 18850708 DOI: 10.1021/ja805261m] [Citation(s) in RCA: 92] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
DNA photolyase is a photoactive flavoprotein that contains three tryptophan residues between the FAD cofactor and the protein surface, the solvent-exposed Trp being located 14.8 A from the flavin. Photoreduction of the neutral radical FADH. form to the catalytically active FADH- form occurs via electron transfer through this chain. The first step in this chain takes 30 ps, the second less than 4 ps. Using a combination of site-directed mutagenesis and femtosecond polarization spectroscopy to discriminate the spectroscopically indistinguishable Trp residues, we show that the third step occurs in less than 30 ps. This implies that the first photoreduction step is rate limiting and that the Trp chain effectively acts as molecular "wire" ensuring rapid and directed long-range charge translocation across the protein. This finding is important for the functioning of the large class of cryptochrome blue-light receptors, where the Trp chain is conserved. In DNA photolyase we make use of the natural photoactivation of the process, but more generally chains of aromatic amino acids may allow very fast long-range electron transfer also in nonphotoactive proteins.
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Affiliation(s)
- Andras Lukacs
- Laboratoire d'Optique et Biosciences, CNRS, Ecole Polytechnique, F-91128 Palaiseau, France
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82
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Rudiuk S, Franceschi-Messant S, Chouini-Lalanne N, Perez E, Rico-Lattes I. Modulation of photo-oxidative DNA damage by cationic surfactant complexation. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2008; 24:8452-8457. [PMID: 18637698 DOI: 10.1021/la800751k] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
The natural packaging of DNA in the cell by histones provides a particular environment affecting its sensitivity to oxidative damage. In this work, we used the complexation of DNA by cationic surfactants to modulate the conformation, the dynamics, and the environment of the double helix. Photo-oxidative damage initiated by benzophenone as the photosensitizer on a plasmid DNA complexed by dodecyltrimethylammonium chloride (DTAC), tetradecyltrimethylammonium chloride (TTAC), cetyltrimethyammonium chloride (CTAC) and bromide (CTAB) was detected by agarose gel electrophoresis. By fluorescent titration in the presence of ethidium bromide (EB) and agarose gel electrophoresis, we experimentally confirmed the complexation diagrams with a critical aggregation concentration on DNA matrix (CAC DNA) delimiting two regions of complexation, according to the DNA-phosphate concentration. The study of the photo-oxidative damage shows, for the first time, a direct correlation between the DNA complexation by these surfactants and the efficiency of DNA cleavage, with a maximum corresponding to the CAC DNA for DTAC and CTAC, and to DNA neutralization for CTAC and CTAB. The localization of a photosensitizer having low water solubility, such as benzophenone, inside the hydrophobic domains formed by the surfactant aggregated on DNA, locally increases the photoinduced cleavage by the free radical oxygen species generated. The inefficiency of a water-soluble quencher of hydroxyl radicals, such as mannitol, confirmed this phenomenon. The detection of photo-oxidative damage constitutes a new tool for investigating DNA complexation by cationic surfactants. Moreover, highlighting the drastically increased sensitivity of a complexed DNA to photo-oxidative damage is of crucial importance for the biological use of surfactants as nonviral gene delivery systems.
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Affiliation(s)
- Sergii Rudiuk
- Laboratoire des IMRCP UMR 5623 CNRS, Université Paul Sabatier, 118 route de Narbonne, 31062 Toulouse, France
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83
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Weng J, Zhang J, Li H, Sun L, Lin C, Zhang Q. Label-free DNA sensor by boron-doped diamond electrode using an ac impedimetric approach. Anal Chem 2008; 80:7075-83. [PMID: 18707136 DOI: 10.1021/ac800610z] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
An electrochemical biosensor using a boron-doped diamond (BDD) electrode is described for differentiating between gene sequences according to DNA hybridization events using an ac impedimetric approach. BDD electrodes were dipped into a 1% solution of polyethylenimine (PEI) to adsorb a thin layer of positively charged PEI on the surface of BDD, then PEI-modified BDD electrodes were used to immobilize negatively charged single-stranded PCR fragments from Exon 7 of human p53 gene. Alternating current impedimetric measurements were first performed on these systems in phosphate buffered saline (PBS) and then upon exposure to single-stranded DNA (ssDNA). When the ssDNA-immobilized BDD electrode and solution ssDNA were completely complementary, a large drop in impedance was measured. Complementary DNA could be clearly detected at concentrations down to 10 (-19) g mL (-1) at a fixed frequency (10 Hz). Higher concentrations of DNA gave faster hybridization with saturation occurring at levels above 1.0 pg mL (-1.) Responses were much lower upon exposure to noncDNA, even at higher concentrations. The results show it is possible to directly detect target DNA at a fixed frequency and without additional labeling.
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Affiliation(s)
- Jian Weng
- Research Center of Biomedical Engineering, College of Materials, Technology Research Center of Biomedical Engineering of Xiamen City, The Key Laboratory of Biomedical Engineering of Fujian Province, Xiamen University, PR China.
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84
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Cadet J, Douki T, Ravanat JL. Oxidatively generated damage to the guanine moiety of DNA: mechanistic aspects and formation in cells. Acc Chem Res 2008; 41:1075-83. [PMID: 18666785 DOI: 10.1021/ar700245e] [Citation(s) in RCA: 414] [Impact Index Per Article: 25.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Nuclear DNA and other molecules in living systems are continuously exposed to endogenously generated oxygen species. Such species range from the unreactive superoxide radical (O2*-)the precursor of hydrogen peroxide (H2O2)to the highly reactive hydroxyl radical (*OH). Exogenous chemical and physical agents, such as ionizing radiation and the UVA component of solar light, can also oxidatively damage both the bases and the 2-deoxyribose moieties of cellular DNA. Over the last two decades, researchers have made major progress in understanding the oxidation degradation pathways of DNA that are most likely to occur from either oxidative metabolism or exposure to various exogenous agents. In the first part of this Account, we describe the mechanistic features of one-electron oxidation reactions of the guanine base in isolated DNA and related model compounds. These reactions illustrate the complexity of the various degradation pathways involved. Then, we briefly survey the analytical methods that can detect low amounts of oxidized bases and nucleosides in cells as they are formed. Recent data on the formation of oxidized guanine residues in cellular DNA following exposure to UVA light, ionizing radiation, and high-intensity UV pulses are also provided. We discuss these chemical reactions in the context of *OH radical, singlet oxygen, and two-quantum photoionization processes.
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Affiliation(s)
- Jean Cadet
- Laboratoire “Lésions des Acides Nucléiques”, SCIB-UMR-E n3 (CEA/UJF) Institut Nanosciences et Cryogénie, CEA/Grenoble, F-38054 Grenoble Cedex 9, France
- Department of Nuclear Medicine and Health Science, University of Sherbrooke, Quebec J1H 5N4, Canada
| | - Thierry Douki
- Laboratoire “Lésions des Acides Nucléiques”, SCIB-UMR-E n3 (CEA/UJF) Institut Nanosciences et Cryogénie, CEA/Grenoble, F-38054 Grenoble Cedex 9, France
| | - Jean-Luc Ravanat
- Laboratoire “Lésions des Acides Nucléiques”, SCIB-UMR-E n3 (CEA/UJF) Institut Nanosciences et Cryogénie, CEA/Grenoble, F-38054 Grenoble Cedex 9, France
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85
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Sun Y, Lutterman DA, Turro C. Role of Electronic Structure on DNA Light-Switch Behavior of Ru(II) Intercalators. Inorg Chem 2008; 47:6427-34. [DOI: 10.1021/ic800560x] [Citation(s) in RCA: 90] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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86
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Hydration Effect on the Intrinsic Magnetism of Natural Deoxyribonucleic Acid as Studied by EMR Spectroscopy and SQUID Measurements. B KOREAN CHEM SOC 2008. [DOI: 10.5012/bkcs.2008.29.6.1233] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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87
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Huang YC, Ge B, Sen D, Yu HZ. Immobilized DNA switches as electronic sensors for picomolar detection of plasma proteins. J Am Chem Soc 2008; 130:8023-9. [PMID: 18517197 DOI: 10.1021/ja8011066] [Citation(s) in RCA: 77] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The sensing principle of a new class of DNA conformational switches (deoxyribosensors) is based on the incorporation of an aptamer as the receptor, whose altered conformation upon analyte binding switches on the conductivity of an adjacent helical conduction path, leading to an increase in the measured electrical signal through the sensor. We report herein the rational design and biochemical testing of candidate deoxyribosensors for the detection and quantitation of a plasma protein, thrombin, followed by surface immobilization of the optimized sensor and its electrochemical testing in both a near-physiological buffer solution and in diluted blood serum. The very high detection sensitivity (in the picomolar range) and specificity, as well as the adaptability of deoxyribosensors for the detection of diverse molecular analytes both small and macromolecular, make this novel sensing methodology an extremely promising one. Such synthetic and robust DNA-based electronic sensors should find broad application in the rapid, miniaturized, and automated on-chip detection of many biomedically relevant substances (such as metabolites, toxins, and disease and tumor markers) as well as of environmental contaminants.
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Affiliation(s)
- Yu Chuan Huang
- Department of Molecular Biology and Biochemistry, Simon Fraser University, Burnaby, British Columbia V5A 1S6, Canada
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88
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Roca-Sanjuán D, Merchán M, Serrano-Andrés L. Modeling hole transfer in DNA: Low-lying excited states of oxidized cytosine homodimer and cytosine–adenine heterodimer. Chem Phys 2008. [DOI: 10.1016/j.chemphys.2008.02.026] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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89
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Choi JY, Lee JM, Lee H, Jung MJ, Kim SK, Kim JM. Mixing ratio-dependent energy transfer from DNA-bound 4′,6-diamidino-2-phenylindole to [Ru(1,10-phenanthroline)2dipyrido[3,2-a:2′,3′-c]phenazine]2+. Biophys Chem 2008; 134:56-63. [DOI: 10.1016/j.bpc.2008.01.006] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2007] [Revised: 01/16/2008] [Accepted: 01/17/2008] [Indexed: 10/22/2022]
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90
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Yang H, Sleiman H. Templated Synthesis of Highly Stable, Electroactive, and Dynamic Metal–DNA Branched Junctions. Angew Chem Int Ed Engl 2008. [DOI: 10.1002/ange.200703741] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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91
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Yang H, Sleiman H. Templated Synthesis of Highly Stable, Electroactive, and Dynamic Metal–DNA Branched Junctions. Angew Chem Int Ed Engl 2008; 47:2443-6. [DOI: 10.1002/anie.200703741] [Citation(s) in RCA: 83] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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92
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Song C, Xia Y, Zhao M, Liu X, Li J, Li L. The electronic structure evolution of DNA during its conformation transition process. Phys Chem Chem Phys 2008; 10:5077-82. [DOI: 10.1039/b804309d] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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93
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Wang XJ, Gui LC, Ni QL, Liao YF, Jiang XF, Tang LH, Zhang Z, Wu Q. π-Stacking induced complexes with Z-shape motifs featuring a complementary approach between electron-rich arene diamines and electron-deficient aromatic N-heterocycles. CrystEngComm 2008. [DOI: 10.1039/b800082d] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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94
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Yamahata C, Collard D, Takekawa T, Kumemura M, Hashiguchi G, Fujita H. Humidity dependence of charge transport through DNA revealed by silicon-based nanotweezers manipulation. Biophys J 2007; 94:63-70. [PMID: 17827222 PMCID: PMC2134877 DOI: 10.1529/biophysj.107.115980] [Citation(s) in RCA: 61] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The study of the electrical properties of DNA has aroused increasing interest since the last decade. So far, controversial arguments have been put forward to explain the electrical charge transport through DNA. Our experiments on DNA bundles manipulated with silicon-based actuated tweezers demonstrate undoubtedly that humidity is the main factor affecting the electrical conduction in DNA. We explain the quasi-Ohmic behavior of DNA and the exponential dependence of its conductivity with relative humidity from the adsorption of water on the DNA backbone. We propose a quantitative model that is consistent with previous studies on DNA and other materials, like porous silicon, subjected to different humidity conditions.
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95
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Xu M, Endres RG, Arakawa Y. The electronic properties of DNA bases. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2007; 3:1539-43. [PMID: 17786897 DOI: 10.1002/smll.200600732] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/17/2023]
Affiliation(s)
- Mingsheng Xu
- Nanoelectronics Collaborative Research Center, IIS, The University of Tokyo, Komaba, Meguro-ku, Tokyo, Japan.
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96
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Affiliation(s)
- Adam P Silverman
- Department of Chemistry, Stanford University, Stanford, California 94305, USA
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97
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Lin X, Kang G, Lu L. DNA/Poly(p-aminobenzensulfonic acid) composite bi-layer modified glassy carbon electrode for determination of dopamine and uric acid under coexistence of ascorbic acid. Bioelectrochemistry 2007; 70:235-44. [DOI: 10.1016/j.bioelechem.2006.02.003] [Citation(s) in RCA: 74] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2005] [Revised: 02/18/2006] [Accepted: 02/20/2006] [Indexed: 11/26/2022]
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98
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Tsutsui K, Koizumi TA, Tanaka K, Hayashi H. Anion-dependent selective formation of intermolecular non-covalent bonds. J Mol Struct 2007. [DOI: 10.1016/j.molstruc.2006.06.020] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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99
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Hiraku Y, Ito K, Hirakawa K, Kawanishi S. Photosensitized DNA Damage and its Protection via a Novel Mechanism†. Photochem Photobiol 2007; 83:205-12. [PMID: 16965181 DOI: 10.1562/2006-03-09-ir-840] [Citation(s) in RCA: 66] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
UVA, which accounts for approximately 95% of solar UV radiation, can cause mutations and skin cancer. Based mainly on the results of our study, this paper summarizes the mechanisms of UVA-induced DNA damage in the presence of various photosensitizers, and also proposes a new mechanism for its chemoprevention. UVA radiation induces DNA damage at the 5'-G of 5'-GG-3' sequence in double-stranded DNA through Type I mechanism, which involves electron transfer from guanine to activated photosensitizers. Endogenous sensitizers such as riboflavin and pterin derivatives and an exogenous sensitizer nalidixic acid mediate DNA photodamage via this mechanism. The major Type II mechanism involves the generation of singlet oxygen from photoactivated sensitizers, including hematoporphyrin and a fluoroquinolone antibacterial lomefloxacin, resulting in damage to guanines without preference for consecutive guanines. UVA also produces superoxide anion radical by an electron transfer from photoexcited sensitizers to oxygen (minor Type II mechanism), and DNA damage is induced by reactive species generated through the interaction of hydrogen peroxide with metal ions. The involvement of these mechanisms in UVA carcinogenesis is discussed. In addition, we found that xanthone derivatives inhibited DNA damage caused by photoexcited riboflavin via the quenching of its excited triplet state. It is thus considered that naturally occurring quenchers including xanthone derivatives may act as novel chemopreventive agents against photocarcinogenesis.
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Affiliation(s)
- Yusuke Hiraku
- Department of Environmental and Molecular Medicine, Mie University Graduate School of Medicine, Tsu, Mie, Japan
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100
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Chapter 29 Rapid detection of organophosphates, Ochratoxin A, and Fusarium sp. in durum wheat via screen printed based electrochemical sensors. ELECTROCHEMICAL SENSOR ANALYSIS 2007. [PMCID: PMC7147853 DOI: 10.1016/s0166-526x(06)49029-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Most of the inhibition bioassays or biosensors for organophosphate and carbamate pesticides are based on the amperometric detection of the enzymatic product of the reaction. Applications of amperometric biosensing strategies for pesticide detection in real or spiked food samples have been recently reported. Most of the applications have been developed for vegetable matrices. Different formats of biosensors have been used: disposable screenprinted choline oxidase biosensors using acetylcholinesterase (AChE) in solution were utilized to detect pesticides. Screen-printed sensor developed using photolithographic conducting copper track, graphite–epoxy composite, and either AChE or butirrylcholinesterase was also used in the analysis of spiked (paraoxon and carbofuran) samples of tap water and fruit juices at sub-nanomolar concentration. Additionally, the developed device, which consists of the hand-held potentiostat, the multiplexer for eight-channel control and a dedicated software, can be used to detect organophosphates pesticides, such as dichlorvos and pirimiphos methyl at contamination level below the maximum residue limit settled by the European Union and also amplified DNA of F. culmorum.
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