Cadmium ion induced bending of phosphorothioate oligonucleotide G10

Abstract

The interaction of cadmium ions and phosphorothioate oligonucleotides G₁₀ (PS-oligoG₁₀) was studied by UV–visible and Raman spectroscopies. It is found that the addition of Cd²⁺ can destroy the hydrogen bonds between guanine–guanine bases of PS-oligoG₁₀ and induce the bending of PS-oligoG₁₀ through coordination of Cd²⁺ with its phosphate groups. The bent PS-oligoG₁₀/Cd²⁺ complex is observed as a nanosphere with a diameter of about 2 nm as shown by TEM.