Vibrations of ordered counterions around left- and right-handed DNA double helixes

International Conference on Dynamics of Systems on the Nanoscale 2012

Perepelytsya, S.M.^1 ; Volkov, S.N.^1

Bogolyubov Institute for Theoretical Physics, NAS of Ukraine, 14-b Metrologichna Str., Kiev, 03680, Ukraine^1

关键词: DNA double helices;    DNA double helix;    Double helix;    Internal structure;    Ionic lattices;    Mass increase;    Raman intensities;    Right handed;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/438/1/012013/pdf
DOI  :  10.1088/1742-6596/438/1/012013

来源: IOP

【 摘 要 】

The vibrations of ordered counterions around right- and left-handed DNA double helix are studied. To determine the modes of DNA conformational vibrations the structure of the double helix with counterions is considered as ionic lattice (ion-phosphate lattice). Using the developed approach the frequencies and Raman intensities for right-handed B-form and left-handed Z-form of the double helix with Na+, K+, Rb+, Cs+, and Mg2+counterions are calculated. The obtained frequencies of vibrations of internal structure elements of the double helix (-1) weakly depend on counterion type. In contrast, the vibrations of the ion-phosphate lattice are determined by counterion mass and charge. The frequencies of ion-phosphate vibrations of alkali metal counterions decrease from 180 to 100 cm-1, while their Raman intensities increase as the counterion mass increases for the both B- and Z-DNA. In the case of Z-DNA new mode of ion-phosphate vibrations near 150 cm-1is found. This mode is characterized by vibrations of Mg2+counterions with respect to the phosphates of different strands of the double helix. Our results explain the experimental Raman spectra of Z-DNA.