Infrared Spectroscopy of Nucleic Acids

Multivariate Analysis for Fourier Transform Infrared Spectra of Complex Biological Systems and Processes

“…Finally, significant spectral differences were found between 890 and 850 cm -1 , where four different bands due to adenine and uracil vibrational modes occur (see Figure 5) [79]. Interestingly, the relative variation of these bands enables to monitor the mRNA polyadenylation extent, a crucial mechanism that regulates transcription.…”

“…In particular, for the NSN oocytes the wavenumber with the highest discrimination weight (1.0) was the 1305 cm -1 , which is due to free adenine, possibly not involved in polyadenylation [79]. In agreement with the temporal pattern of the adenine band at 870 cm -1 , discussed previously, the 1305 cm -1 component displayed a higher intensity at MII, confirming that an inadequate mRNA polyadenylation could preclude NSN oocytes from a successful embryonic development (see Figure 6).…”

Calculation and analysis of vibrational spectra of adenine–thymine, guanine–cytosine, and adenine–uracil complementary pairs in the condensed state

“…Usually study of the experimental spectra is accompanied by nonempirical calculations of the normal vibrations and their interpretations. As shown by analysis of the vibrational spectra, in the range 200-1800 cm -1 major changes are observed in the spectra of complementary pairs compared with the spectra of the nucleic acid bases in the high-frequency region (1400-1800 cm -1 ) and the low-frequency region (200-400 cm -1 ): in the high-frequency region, formation of hydrogen bonds C=O...HN and NH 2 ...O leads to corresponding changes in the frequencies and intensities of the stretching vibrations (C=O) and bending vibrations of the amino group, and in the low-frequency region it leads to the appearance of vibrations of the hydrogen bond (see, for example, [8] bond, for example, each of the three in the guanine-cytosine pair, and its dependence on their structural positions in the pair. Furthermore, the nature of the relative displacement of the nucleic acid bases along the hydrogen bonds has not been analyzed, although it is important for studying the mechanism for transfer of a hydrogen atom between the nucleic acid bases and tautomer formation.…”

“…The effect of a hydrogen bond on the vibrational spectrum can be determined by comparing the spectra of the isolated molecule and the molecule in the liquid or solid phase, or the spectra of the isolated molecule and the spectra of isolated dimers or an isolated complex of the molecule, for example with water. In all these cases the position of the bands in the IR spectra and their intensity change, which is the major carrier of information about the effect of a hydrogen bond on the change in structure and properties of the molecule.For nucleic acid base pairs, an analogous study has been carried out in the following directions: the change in the IR and Raman spectra of the complementary pairs has been studied in different phase states and different temperature intervals; the spectra of isolated nucleic acid bases have been compared with the spectra of the complementary pairs; the spectra of the pairs adenine-thymine, guanine-cytosine have been compared with the spectra of the corresponding nucleotides and nucleosides [8][9][10][11][12][13][14][15][16][17][18][19][20][21][22]. Usually study of the experimental spectra is accompanied by nonempirical calculations of the normal vibrations and their interpretations.…”

Fourier Transform Infrared Microspectroscopy as a Tool for Embryonic Stem Cell Studies

“…Several reviews discuss extensively the Amide I band assignment to protein secondary structures (for instance Barth, 2007;Barth & Zscherp, 2002;Arrondo & Goni, 1999;Arrondo et al, 1993) and here we report only a scheme for protein in notdeuterated solvent: alpha-helices (1660-1648 cm -1 ), beta-sheets (1640-1623 cm -1 and 1695-1674 cm -1 ), turns (1686-1662 cm -1 ), random coils (1657-1642 cm -1 ), and aggregation and protein-protein interactions (1630-1620 cm -1 and 1698-1692 cm -1 ) . Concerning nucleic acids, their IR absorption is very complex and covers a wide range of frequencies (Banyay et al, 2003;Zhizhina & Oleinik, 1972;Tsuboi, 1961). For simplicity, the range of absorption is conventionally divided in different spectral regions.…”