Abstract
2-Aminopurine is a fluorescent probe widely used to study local dynamics as well as charge and energy transfer reactions in DNA/RNA. Despite its broad utilization, the nonradiative relaxation pathways responsible for the variation in its fluorescence quantum yield and fluorescence lifetime in different solvents are still under scrutiny. In this work we use steady-state absorption and emission spectroscopy and broad-band transient absorption covering the time scale from femtoseconds to microseconds to investigate the excited-state dynamics of 2-aminopurine 2’-deoxyriboside (2APdr) in acetonitrile, ethanol, and aqueous buffer solution at pH 7. It is shown that up to ≈40% of the initial excited-state population decays by intersystem crossing to the triplet state depending on the solvent used, thus competing effectively with fluorescence emission. Furthermore, the rate of formation and yield of the triplet state depend sensitively on the hydrogen-donor ability and polarity of the solvent.
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01 December 2013
A Correction to this paper has been published: https://doi.org/10.1007/BF03549805
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D. C. Ward, E. Reich, L. Stryer, Fluorescence studies of nucleotides and polynucleotides. I. Formycin, 2-aminopurine riboside, 2,6-diaminopurine riboside, and their derivatives, J. Biol. Chem., 1969, 244, 1228–1237.
J. Smagowicz, K. L. Wierzchowski, Lowest excited states of 2-aminopurine, J. Lumin., 1974, 8, 210–232.
C. E. Crespo-Hernández, B. Cohen, P. M. Hare, B. Kohler, Ultrafast excited-state dynamics in nucleic acids, Chem. Rev., 2004, 104, 1977–2019.
E. L. Rachofsky, R. Osman, J. B. A. Ross, Probing structure and dynamics of DNA with 2-aminopurine: effects of local environment on fluorescence, Biochemistry, 2001, 40, 946–956.
T. M. Nordlund, Sequence, structure and energy transfer in DNA, Photochem. Photobiol., 2007, 83, 625–636.
H.-W. Lee, K. T. Briggs, J. P. Marino, Dissecting structural transition in the HIV-1 dimerization initiation site RNA using 2-aminopurine fluorescence, Methods, 2009, 49, 118–127.
L. Zhao, T. Xia, Probing RNA conformational dynamics and heterogeneity using femtosecond time-resolved fluorescence spectroscopy, Methods, 2009, 49, 128–135.
F. Wachowius, C. Hobartner, Chemical RNA modifications for studies of RNA structure and dynamics, ChemBioChem, 2010, 11, 469–480.
S. O. Kelley, J. K. Barton, Electron transfer between bases in double helical DNA, Science, 1999, 283, 375–381.
C. Wan, T. Fiebig, O. Schiemann, J. K. Barton, A. H. Zewail, Femtosecond direct observation of charge transfer between bases in DNA, Proc. Natl. Acad. Sci. U. S. A., 2000, 97, 14052–14055.
M. A. O’Neill, H.-C. Becker, C. Wan, J. K. Barton, A. H. Zewail, Ultrafast dynamics in DNA-mediated electron transfer: base gating and the role of temperature, Angew. Chem., Int. Ed., 2003, 42, 5896–5900.
V. Shafirovich, N. E. Geacintov, Proton-coupled electron transfer reactions at a distance in DNA duplexes, Top. Curr. Chem., 2004, 237, 129–157.
J. C. Genereux, J. K. Barton, Mechanisms for DNA charge transport, Chem. Rev., 2010, 110, 1642–1662.
J. C. Genereux, S. M. Wuerth, J. K. Barton, Single-step charge transport through DNA over long distances, J. Am. Chem. Soc., 2011, 133, 3863–3868.
K. D. Raney, L. C. Sowers, D. P. Millar, S. J. Benkovic, A fluorescence-based assay for monitoring helicase activity, Proc. Natl. Acad. Sci. U. S. A., 1994, 91, 6644–6648.
M. W. Frey, L. C. Sowers, D. P. Millar, S. J. Benkovic, The nucleotide analog 2-aminopurine as a spectroscopic probe of nucleotide incorporation by the Klenow fragment of Escherichia coli polymerase I and bacteriophage T4 DNA polymerase, Biochemistry, 1995, 34, 9185–9192.
K. Liebert, A. Hermann, M. Schlickenrieder, A. Jeltsch, Stopped-flow and mutational analysis of base flipping by the Escherichia coli Dam DNA-(adenine-N6)-methyltransferase, J. Mol. Biol., 2004, 341, 443–454.
D. J. Krosky, F. Song, J. T. Stivers, The origins of high-affinity enzyme binding to an extrahelical DNA base, Biochemistry, 2005, 44, 5949–5959.
T. Lenz, E. Y. M. Bonnist, G. Pljevaljcic, R. K. Neely, D. T. F. Dryden, A. J. Scheidig, A. C. Jones, E. Weinhold, 2-Aminopurine flipped into the active site of the adenine-specific DNA methyltransferase M.TaqI: crystal structures and time-resolved fluorescence, J. Am. Chem. Soc., 2007, 129, 6240–6248.
S. G. Srivatsan, A. A. Sawant, Fluorescent ribonucleoside analogues as probes for investigating RNA structure and function, Pure Appl. Chem., 2011, 83, 213–232.
A. Broo, A theoretical investigation of the physical reason for the very different luminescence properties of the two isomers adenine and 2-aminopurine, J. Phys. Chem. A, 1998, 102, 526–531.
E. Nir, K. Kleinermanns, L. Grace, M. S. de Vries, On the photochemistry of purine nucleobases, J. Phys. Chem. A, 2001, 105, 5106–5110.
L. Serrano-Andrés, M. Merchán, A. C. Borin, Adenine and 2-aminopurine: paradigms of modern theoretical photochemistry, Proc. Natl. Acad. Sci. U. S. A., 2006, 103, 8691–8696.
S. Perun, A. L. Sobolewski, W. Domcke, Ab initio studies of the photophysics of 2-aminopurine, Mol. Phys., 2006, 104, 1113–1121.
K. A. Seefeld, C. Plützer, D. Löwenich, T. Häber, R. Linder, K. Kleinermanns, J. Tatchen, C. M. Marian, Tautomers and electronic states of jet-cooled 2-aminopurine investigated by double resonance spectroscopy and theory, Phys. Chem. Chem. Phys., 2005, 7, 3021–3026.
K. Feng, G. Engler, K. Seefeld, K. Kleinermanns, Dispersed fluorescence and delayed ionization of jet-cooled 2-aminopurine: relaxation to a dark state causes weak fluorescence, ChemPhysChem, 2009, 10, 886–889.
S. Lobsiger, R. K. Sinha, M. Trachsel, S. Leutwyler, Low-lying excited states and nonradiative processes of the adenine analogues 7H- and 9H-2-aminopurine, J. Chem. Phys., 2011, 134, 114307.
K. L. Wierzchowski, K. Berens, A. G. Szabo, Triplet-triplet absorption studies of the intersystem crossing mechanism of 2-aminopurines, J. Lumin., 1975, 10, 331–343.
T. Fiebig, C. Wan, A. H. Zewail, Femtosecond charge transfer dynamics of a modified DNA base: 2-aminopurine in complexes with nucleotides, ChemPhysChem, 2002, 3, 781–788.
O. F. A. Larsen, I. H. M. van Stokkum, M.-L. Groot, J. T. M. Kennis, R. van Grondelle, H. van Amerongen, Electronic states in 2-aminopurine revealed by ultrafast transient absorption and target analysis, Chem. Phys. Lett., 2003, 371, 157–163.
G. Kodali, K. A. Kistler, S. Matsika, R. J. Stanley, 2-Aminopurine excited state electronic structure measured by Stark spectroscopy, J. Phys. Chem. B, 2008, 112, 1789–1795.
R. K. Sinha, S. Lobsiger, M. Trachsel, S. Leutwyler, Vibronic spectra of jet-cooled 2-aminopurine·H2O clusters studied by UV resonant two-photon ionization spectroscopy and quantum chemical calculations, J. Phys. Chem. A, 2011, 115, 6208–6217.
R. K. Neely, S. W. Magennis, D. T. F. Dryden, A. C. Jones, Evidence of tautomerism in 2-aminopurine from fluorescence lifetime measurements, J. Phys. Chem. B, 2004, 108, 17606–17610.
C. Santhosh, P. C. Mishra, Electronic spectra of 2-aminopurine and 2,6-diaminopurine phototautomerism and fluorescence reabsorption, Spectrochim. Acta, Part A, 1991, 47, 1685–1693.
J. R. Lakowicz, Topics in Fluorescence Spectroscopy. Volume 2. Principles, Plenum Press, New York, 1991.
L. Dodson, R. A. Vogt, C. Reichardt, J. Marks, C. E. Crespo-Hernández, Photophysical and photochemical properties of the pharmaceutical compound salbutamol in aqueous solutions, Chemosphere, 2011, 83, 1513–1523.
H. C. Börresen, The fluorescence of guanine and guanosine. Effects of temperature and viscosity on fluorescence polarization and quenching, Acta Chem. Scand., 1967, 21, 920–936.
C. Reichardt, R. A. Vogt, C. E. Crespo-Hernández, On the origin of ultrafast nonradiative transitions in nitro-polycyclic aromatic hydrocarbons: excited-state dynamics in 1-nitronaphthalene, J. Chem. Phys., 2009, 131, 224518.
T. Nakayama, Y. Amijima, K. Ibuki, K. Hamanoue, Construction of a subpicosecond double-beam laser photolysis system utilizing a femtosecond Ti:sapphire oscillator and three Ti:sapphire amplifiers (a regenerative amplifier and two double passed linear amplifiers), and measurements of the transient absorption spectra by a pump-probe method, Rev. Sci. Instrum., 1997, 68, 4364–4371.
I. H. M. van Stokkum, D. S. Larsen, R. van Grondelle, Global and target analysis of time-resolved spectra, Biochim. Biophys. Acta, 2004, 1657, 82–104.
I. H. M. van Stokkum, D. S. Larsen, R. van Grondelle, Erratum to “Global and target analysis of time-resolved spectra”, Biochim. Biophys. Acta, 2004, 1658, 262.
C. Capellos and B. H. J. Bielski, Kinetic Systems, Wiley Interscience, New York, 1972.
R. A. Vogt, T. G. Gray, C. E. Crespo-Hernández, Subpicosecond intersystem crossing in mono- and di-(organophosphine)gold(i) naphthalene derivatives in solution, J. Am. Chem. Soc., 2012, 134, 14808–14817.
I. Carmichael, G. L. Hug, Triplet-triplet absorption spectra of organic molecules in condensed phases, J. Phys. Chem. Ref. Data, 1986, 15, 1–32.
A. R. Horrocks, F. Wilkinson, Triplet state formation efficiencies of aromatic hydrocarbons in solution, Proc. R. Soc. London, Ser. A, 1968, 306, 257–273.
D. N. Dempster, T. Morrow, M. F. Quinn, Extinction coefficients for triplet-triplet absorption in ethanol solutions of anthracene, naphthalene, 2,5-diphenyloxale, 7-diethylamino-4-methyl coumarin and 4-methyl-7-amino-carbostyril, J. Photochem., 1973/74, 2, 329–341.
A. Singh, Triplet state formation in pulse radiolysis, Radiat. Res. Rev., 1972, 4, 1–69.
E. Hayon, Yield of ions and excited states produced in the radiolysis of polar organic liquids, J. Chem. Phys., 1970, 53, 2353–2358.
M. Narayanan, G. Kodali, Y. Xing, R. J. Stanley, Photoinduced electron transfer occurs between 2-aminopurine and the DNA nucleic acid monophosphates: results from cyclic voltammetry and fluorescence quenching, J. Phys. Chem. B, 2010, 114, 10573–10580.
C. Gabriel, S. Gabriel, E. H. Grant, B. S. J. Halstead, D. M. P. Mingos, Dielectric parameters relevant to microwave dielectric heating, Chem. Soc. Rev., 1998, 27, 213–223.
M. L. Horng, J. A. Gardecki, A. Papazyan, M. Maroncelli, Subpicosecond measurements of polar solvation dynamics: coumarin 153 revisited, J. Phys. Chem., 1995, 99, 17311–17337.
S. K. Pal, L. Zhao, T. Xia, A. H. Zewail, Site- and sequence-selective ultrafast hydration of DNA, Proc. Natl. Acad. Sci. U. S. A., 2003, 100, 13746–13751.
N. J. Turro, V. Ramamurthy and J. C. Scaiano, Principles of Molecular Photochemistry: An Introduction, University Science Books, Sausalito, CA, 2009.
P. M. Hare, C. E. Crespo-Hernández, B. Kohler, Solvent-dependent photophysics of 1-cyclohexyluracil: ultrafast branching in the initial bright state leads nonradiatively to the electronic ground state and a long-lived 1nπ* state, J. Phys. Chem. B, 2006, 110, 18641–18650.
P. M. Hare, C. E. Crespo-Hernández, B. Kohler, Internal conversion to the electronic ground state occurs via two distinct pathways for pyrimidine bases in aqueous solution, Proc. Natl. Acad. Sci. U. S. A., 2007, 104, 435–440.
W.-M. Kwok, C. Ma, D. L. Phillips, A doorway state leads to photostability or triplet photodamage in thymine DNA, J. Am. Chem. Soc., 2008, 130, 5131–5139.
R. González-Luque, T. Climent, I. González-Ramírez, M. Merchán, L. Serrano-Andrés, Singlet-triplet states interaction regions in DNA/RNA nucleobases hypersurfaces, J. Chem. Theor. Comput., 2010, 6, 2103–2114.
M. Etinski, T. Fleig, C. M. Marian, Intersystem crossing and characterization of dark states in the pyrimidine nucleobases uracil, thymine, and 1-methylthymine, J. Phys. Chem. A, 2009, 113, 11809–11816.
C. Salet, R. Bensasson, Studies on thymine and uracil triplet excited state in acetonitrile and water, Photochem. Photobiol., 1975, 22, 231–235.
C. Salet, R. Bensasson, R. S. Becker, Triplet excited states of pyrimidine nucleosides and nucleotides, Photochem. Photobiol., 1979, 30, 325–329.
H. Görner, Transients of uracil and thymine derivatives and the quantum yields of electron ejection and intersystem crossing upon 20 ns photolysis at 248 nm, Photochem. Photobiol., 1990, 52, 935–948.
H. Görner, Phosphorescence of nucleic acids and DNA components at 77 K, J. Photochem. Photobiol., B, 1990, 5, 359–377.
J. Cadet and P. Vigny, in Bioorganic Photochemistry, ed. H. Morrison, New York, 1990, pp. 1–272.
C. T. Middleton, K. de La Harpe, C. Su, Y. K. Law, C. E. Crespo-Hernández, B. Kohler, DNA excited-state dynamics: from single bases to the double helix, Annu. Rev. Phys. Chem., 2009, 60, 217–239.
M. Richter, P. Marquetand, J. González-Vázquez, I. Sola, L. González, SHARC - ab initio molecular dynamics with surface hopping in the adiabatic representation including arbitrary couplings, J. Chem. Theor. Comput., 2011, 7, 1253–1258.
P. Marquetand, M. Richter, J. González-Vázquez, L. González, Nonadiabatic ab initio molecular dynamics including spin-orbit coupling and laser fields, Faraday Discuss., 2011, 153, 261–273.
G. Granucci, M. Persico, G. Spighi, Surface hopping trajectory simulations with spin-orbit and dynamical couplings, J. Chem. Phys., 2012, 137, 22A501.
M. Richter, P. Marquetand, J. González-Vásquez, I. Sola, L. González, Femtosecond intersystem crossing in the DNA nucleobase cytosine, J. Phys. Chem. Lett., 2012, 3, 3090–3095.
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† Electronic supplementary information (ESI) available. See DOI: 10.1039/c3pp25437b
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Reichardt, C., Wen, C., Vogt, R.A. et al. Role of intersystem crossing in the fluorescence quenching of 2-aminopurine 2’-deoxyriboside in solution. Photochem Photobiol Sci 12, 1341–1350 (2013). https://doi.org/10.1039/c3pp25437b
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DOI: https://doi.org/10.1039/c3pp25437b