writer：Xu Li#, Liang Ma#, Xiaolin Lu*
keywords：Oligonucleotide Duplex, metal ions, SFG, water
source：期刊
specific source：Langmuir, invited feature article, accepted.
Issue time：2018年

Published as an invited feature article.

Solvation of DNA in water facilitates the formation of a hydration layer surrounding it, thus stabilizing the DNA duplex in the biological aqueous environment. In this study, via using the lipid bilayer as a soft substrate to accommodate the duplex oligonucleotide, the structure of the water layer surrounding the oligonucleotide was detected under the perturbation of the calcium ions (Ca2+) with chiral and achiral sum frequency generation (SFG) vibrational spectroscopy. With increasing the Ca2+ concentration, both the chiral and achiral water vibrational signals showed the similar concentration-dependent changes, i.e. an initial decrease phase followed by an increase phase. However, when the Ca2+ concentrations were adjusted within the range comparable to those in the human serum, the chiral water vibrational signals kept nearly unchanged, whereas the achiral water vibrational signals still changed as a function of the Ca2+ concentration. Therefore, the current experimental result supports the possible protection function of the chiral hydration layer against the Ca2+ ions, which generally exist in the cell sap and play important roles in many biological functions.

https://pubs.acs.org/doi/10.1021/acs.langmuir.8b01763