The aim of this study was to investigate the effects of rare earth elements （REEs） in preventing Hg^2＋ pollution, using fish intestinal DNA in vitro and study the mechanism of the interactions between Hg^2＋ , La^3...The aim of this study was to investigate the effects of rare earth elements （REEs） in preventing Hg^2＋ pollution, using fish intestinal DNA in vitro and study the mechanism of the interactions between Hg^2＋ , La^3＋ , the mixture of La^3＋ and Hg^2＋ and DNA by spectroscopy. The interactions between Hg^2＋ , La^3＋ , the mixture of La^3＋ and Hg^2＋ and DNA from fish intestine in vitro was investigate by using absorption spectrum and fluorescence emission spectrum. Ultraviolet absorption spectra indicated that the addition of Hg^2＋ , La^3＋ , and the mixture of La^3＋ and Hg^2＋ to DNA generated obvious hypochromic effect. Meanwhile, the 205.2 nm peak of DNA blue and the 258.2 nm peak of DNA red shifted. The hypochromic effect and peak shift was caused by these ions in an order of Hg^2＋ 〉 Hg^2＋ ＋ La^3＋ 〉 La^3＋ . The fluorescence emission spectra showed that as the addition of Hg^2＋ , La^3＋ , and the mixture of La^3＋ and Hg^2＋ , the emission peak at about 416.2 nm of DNA did not obviously change, but the fluorescence intensity reduced gradually with the order in treatment was Hg^2＋ 〉 Hg^2＋ 〉 La^3＋ 〉 La^3＋ . Hg^2＋ , La^3＋ , and the mixture of La^3＋ and Hg^2＋ had 1.12, 0.58, and 0.81 binding sites to DNA, the fluorescence quenching of DNA caused by them all attributed to static quenching. The binding constants KA of binding sites were 3.82×10^4 and 4.22×10^2 L·mol^-1 ; 2.50×10^4 and 2.95×10^3 L·mol^-1 ; 3.05×10^4 and 1.00×10^3 L·mol^-1. The results showed that La^3＋ could relieve destruction caused by Hg^2＋ on the DNA structure.展开更多
基金Project supported by the National Natural Science Foundation of China (20671067)
文摘The aim of this study was to investigate the effects of rare earth elements （REEs） in preventing Hg^2＋ pollution, using fish intestinal DNA in vitro and study the mechanism of the interactions between Hg^2＋ , La^3＋ , the mixture of La^3＋ and Hg^2＋ and DNA by spectroscopy. The interactions between Hg^2＋ , La^3＋ , the mixture of La^3＋ and Hg^2＋ and DNA from fish intestine in vitro was investigate by using absorption spectrum and fluorescence emission spectrum. Ultraviolet absorption spectra indicated that the addition of Hg^2＋ , La^3＋ , and the mixture of La^3＋ and Hg^2＋ to DNA generated obvious hypochromic effect. Meanwhile, the 205.2 nm peak of DNA blue and the 258.2 nm peak of DNA red shifted. The hypochromic effect and peak shift was caused by these ions in an order of Hg^2＋ 〉 Hg^2＋ ＋ La^3＋ 〉 La^3＋ . The fluorescence emission spectra showed that as the addition of Hg^2＋ , La^3＋ , and the mixture of La^3＋ and Hg^2＋ , the emission peak at about 416.2 nm of DNA did not obviously change, but the fluorescence intensity reduced gradually with the order in treatment was Hg^2＋ 〉 Hg^2＋ 〉 La^3＋ 〉 La^3＋ . Hg^2＋ , La^3＋ , and the mixture of La^3＋ and Hg^2＋ had 1.12, 0.58, and 0.81 binding sites to DNA, the fluorescence quenching of DNA caused by them all attributed to static quenching. The binding constants KA of binding sites were 3.82×10^4 and 4.22×10^2 L·mol^-1 ; 2.50×10^4 and 2.95×10^3 L·mol^-1 ; 3.05×10^4 and 1.00×10^3 L·mol^-1. The results showed that La^3＋ could relieve destruction caused by Hg^2＋ on the DNA structure.
