A library of IR bands of nucleic acids in solution

The system with zwitterionic lactose-based surfactant for complexation and delivery of small interfering ribonucleic acid—A structural and spectroscopic study

“…The FTIR spectra reveal changes in the intensities (Fig. S1 37 ) of the bands at 811 cm À1 , 864 cm À1 , and 876 cm À1 , which are markers of the ribose fragments in the N-type conformation (C3 0 -endo/anti) in nucleic acids 25,29,30 and the shifts of the bands in the range 823-826 cm À1 accompanying the increase in the surfactant concentration (the ribose S-conformation, C2 0 -endo/anti). The changes in FTIR spectra observed with increasing surfactant concentration evidence a direct influence of the surfactant on ribose conformation.…”

“…S1 37 ), and 995 cm À1 in the FTIR spectra towards longer wavenumbers, which can be a result of the interaction of surfactant with 2 0 -OH groups of the nucleic acid or ribose. [30][31][32] For A-RNA in solution, the characteristic bands at 1244 cm À1 and 1217 cm À1 are assigned to the stretching asymmetric vibrations of PO 2 groups. 25,30,32,33 With increasing surfactant concentration, the band 1217 cm À1 is shifted towards shorter wavenumbers which may indicate disturbance of A-RNA structure (Fig.…”

Evaluating the Effects of the Nonplanarity of Nucleic Acid Bases on NMR, IR, and Vibrational Circular Dichroism Spectra: A Density Functional Theory Computational Study

“…In the case of dominant bands at 1050 cm -1 and bands at 1330 and 1390 cm -1 the situation was the opposite. The calculated band at 1335 cm -1 assigned to the base-sugar vibrations sensitive to the glycosidic bond rotation 44 was virtually the same in all three dG conformers. The differences in the IR spectra calculated for the two dG nucleosides with opposite out-of-plane deviations of N9 were larger than those between the IR spectrum for dG with maximal and minimal pyramidalization (the 940 or 1080 cm -1 bands).…”

“…44 It should be mentioned that the normal vibration modes were highly delocalized and thus the calculated peaks could not be assigned solely to certain well-resolved molecular motions. Nevertheless, several specific changes in the calculated spectra were observed.…”

“…Any interpretation of IR spectra measured in NAs with the calculated assignments would be difficult, as none of the calculated trends would be distinguishable in the complicated mixture of many similar IR bands originating from base-sugar and sugar-phosphate vibrations. 44 However, under special conditions when a certain kind of notable pyramidalization at the glycosidic nitrogen is repeated in an NA polynucleotide, the calculated trends for out-of-plane vibrations at N9 may be amplified and become distinguishable from other vibrations.…”