The Spectral Properties and Photostability of DNA, RNA, and Oligonucleotides

Abstract

The present work discusses the results of comparative investigations of the optical absorption, luminescence, and photostability of the biomacromolecules (DNA, RNA), as well as synthetic poly- and oligonucleotides. The separate nucleotides in DNA and RNA are examined as almost independent absorbing centers. It is confirmed that the main triplet excitons traps responsible for the DNA phosphorescence emission are AT-complexes in DNA. In contrast toDNA, the main triplet excitons traps in RNA are adenosine bases. These bases are the most photostable against UV-irradiation as compared with all other nucleotides in both DNA and RNA. The fact of the photostability of adenosine bases and the AT-complex provides the existence of the DNA/RNA self-protection mechanisms against a damage caused by UV-irradiation. It is found the deoxyribonucleotides are more photostable than the correspondingribonucleotides. So, the results presented here show that DNA is more photostable than RNA.

The spectral properties of DNA and RNA macromolecules at low temperatures: fundamental and applied aspects

“…The data obtained in our studies at 77 K are close enough to those obtained earlier in a number of works [18][19][20][21][22][23][24][25][26][27]. Our original contribution is connected with the use of even lower temperatures (4.2 K-30 K) [7][8][9][10][11][12][13]. This gives the possibility of defining the system of electronic energy levels in a more precise manner.…”

“…This fact is additional proof that the adenine triplet level is the lowest. The obtained relative position of the triplet level of dAMP is strongly supported by our experiments on the photodegradation of mononucleotides and DNA [8][9][10]. The positions of triplet states do not essentially depend on T (according to our measurements).…”

“…The optical absorption, fluorescence and phosphorescence spectra (at ambient and low temperatures) of separated nucleotides (monomers) were studied in [7][8][9][10][11][12][13]. The data obtained in our studies at 77 K are close enough to those obtained earlier in a number of works [18][19][20][21][22][23][24][25][26][27].…”

“…The optical absorption of DNA and RNA, as well as of the oligonucleotide (dodecanucleotide) d(CCCGGGTTTAAA), specially designed and synthesized for the DNA electronic structure studies, was considered in [7][8][9][10][11][12][13][14][15][16][17]. Our results obtained on DNA, RNA and low-molecular model compounds were similar to those reported in [18][19][20][21][22][23][24][25][26][27].…”

Plasmonic Nanocavity Metasurface Based on Laser-Structured Silver Surface and Silver Nanoprisms for the Enhancement of Adenosine Nucleotide Photoluminescence

“…However, at room temperature, most nucleic acids and nucleotides are considered to be virtually nonfluorescing because of the very low quantum yields of their intrinsic fluorescence; e.g., for DNA bases, they were reported − to be 10 –5 –10 –4 . In particular, the quantum yield for 5′-deoxyadenosine monophosphate (dAMP), under study in the present work, is known to be 7 × 10 –5 at room temperature. , dAMP is chosen for our experiments because it is the most photostable among the other nucleotides. − Therefore, specific labeling of these molecules with fluorescent dyes becomes necessary for DNA sequencing, genetic analysis, and cellular and in situ imaging in different optical windows. − However, the use of such specific labels is labor-intensive, time-consuming, and, hence, expensive. Similarly, the label-free detection of proteins and peptides employing fluorescence spectroscopy can be challenging.…”