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Proceedings Paper

Some aspects of the photophysics of DNA
Author(s): Solon Georghiou; Guangyuan Ge; Ralph D. Weidner; Shen Zhu; C. R. Huang
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Paper Abstract

We have made room-temperature measurements of transfer of electronic energy in calf thymus DNA in which 75% of the guanine residues are methylated at position N-7. The methylated residues absorb light at much longer wavelengths than the nonmethylated residues and, as a result, constitute an irreversible energy trap. For excitation at 270 nm the efficiency of intrastrand transfer is found to be 0.31. We note that this is the first measurement of the efficiency of energy transfer along the double helix of a nucleic acid. In addition, the data have been simulated by using a stochastic model in terms of Förster's theory for dipole-dipole transfer. The adequacy of the latter is discussed. Preliminary measurements of the dependence of the fluorescence spectrum and of the fluorescence anisotropy of the alternating polynucleotide poly(dA-dT).poly(dA-dT) on the excitation wavelength and temperature are interpreted in terms of emission from molecular complexes formed between A and T residues.

Paper Details

Date Published: 1 May 1990
PDF: 8 pages
Proc. SPIE 1204, Time-Resolved Laser Spectroscopy in Biochemistry II, (1 May 1990); doi: 10.1117/12.17697
Show Author Affiliations
Solon Georghiou, Univ. of Tennessee (United States)
Guangyuan Ge, Univ. of Tennessee (United States)
Ralph D. Weidner, Univ. of Tennessee (United States)
Shen Zhu, Univ. of Tennessee (United States)
C. R. Huang, Univ. of Tennessee (United States)

Published in SPIE Proceedings Vol. 1204:
Time-Resolved Laser Spectroscopy in Biochemistry II
Joseph R. Lakowicz, Editor(s)

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