Research ArticleChemistry

Reactivity of prehydrated electrons toward nucleobases and nucleotides in aqueous solution

See allHide authors and affiliations

Science Advances  15 Dec 2017:
Vol. 3, no. 12, e1701669
DOI: 10.1126/sciadv.1701669
  • Fig. 1 Transient absorption kinetic traces of Embedded Image in liquid water containing G, A, C, and T compounds with different concentrations (10 to 150 mM).

    To increase the solubilities of purine nucleobases, the solutions were prepared in 90 mM NaOH followed by the work of Wang et al. (22). Radiolytic yields of Embedded Image are shown in the left axes, and these correspond to the absorbance in the right axes. The dose per electron pulse was 55.3 grays (Gy). The radiolytic yield of Embedded Image is not affected even in 50 mM G solution within 1% uncertainty. The solid line is the theoretical fit; we have obtained it using time-dependent rate constants. ΔO.D.900nm, optical density at 900 nm.

  • Fig. 2 Transient absorption spectra of the nucleotide anion radicals (GMP•−, AMP•−, CMP•−, and TMP•− or the TNIs of nucleotides) observed at 7 ps (right) and the kinetics of Embedded Image in the presence of 250 mM nucleotides in water (left).

    We have obtained the spectra of absorbing radicals via subtraction of the appropriate extent of the absorption spectrum of Embedded Image from the original experimentally recorded two-dimensional (2D) spectrum using global data analysis.

  • Fig. 3 The comparison of yield of the formation of GMP anion radical (GMP•−) with that of Embedded Image trapped by the GMP molecule before the hydration is complete.

    The filled gray areas represent the changes of the total yield of anion radicals from that of trapped electrons evolving with the delay time up to 170 ps.

  • Fig. 4 Scheme representing the reactivity of Embedded Image and Embedded Image with XMP and possible pathways of the decay of the excited anion radical XMP*•− (TNI).
  • Fig. 5 Transient absorption kinetics of Embedded Image in the absence (blue curve) and in the presence of different concentrations of G in 6 M H3PO4 solutions replacing the neat water as a medium.

    The normalized transient spectra consist of three absorbing species, Embedded Image (black), H2PO4 (red), and the protonated G nucleobase anion radical G(H+)•− (blue), produced within the electron pulse.

Supplementary Materials

  • Supplementary material for this article is available at http://advances.sciencemag.org/cgi/content/full/3/12/e1701669/DC1

    fig. S1. Schematic diagram representing the energetic cycle for the adiabatic electron solvation and its reaction with a DNA nucleobase.

    fig. S2. Time-resolved 2D transient absorption map of irradiated neat water.

    fig. S3. Time-resolved 2D transient absorption map of the irradiated solution of GMP at 250 mM.

    fig. S4. Time-resolved 2D transient absorption map of the irradiated solution of AMP at 250 mM.

    fig. S5. Time-resolved 2D transient absorption map of the irradiated solution of CMP at 250 mM.

    fig. S6. Time-resolved 2D transient absorption map of the irradiated solution of TMP at 250 mM.

    fig. S7. Time-dependent population and normalized spectra of hydrated electron and GMP radical anions.

    fig. S8. Time-dependent population and normalized spectra of hydrated electron and TMP radical anions.

    fig. S9. Time-dependent signal population and normalized spectra of hydrated electron and CMP radical anions.

    fig. S10. Time-dependent population and normalized spectra of hydrated electron and AMP radical anions.

  • Supplementary Materials

    This PDF file includes:

    • fig. S1. Schematic diagram representing the energetic cycle for the adiabatic electron solvation and its reaction with a DNA nucleobase.
    • fig. S2. Time-resolved 2D transient absorption map of irradiated neat water.
    • fig. S3. Time-resolved 2D transient absorption map of the irradiated solution of GMP at 250 mM.
    • fig. S4. Time-resolved 2D transient absorption map of the irradiated solution of AMP at 250 mM.
    • fig. S5. Time-resolved 2D transient absorption map of the irradiated solution of CMP at 250 mM.
    • fig. S6. Time-resolved 2D transient absorption map of the irradiated solution of TMP at 250 mM.
    • fig. S7. Time-dependent population and normalized spectra of hydrated electron and GMP radical anions.
    • fig. S8. Time-dependent population and normalized spectra of hydrated electron and TMP radical anions.
    • fig. S9. Time-dependent signal population and normalized spectra of hydrated electron and CMP radical anions.
    • fig. S10. Time-dependent population and normalized spectra of hydrated electron and AMP radical anions.

    Download PDF

    Files in this Data Supplement:

Stay Connected to Science Advances

Navigate This Article