d(GGTATACC)_2与乙二胺四乙酸在溶液中的相互作用

Interaction of d(GGTATACC) 2 and EDTA in Solution

空气的尘埃中含有一种核苷酸降解酶，这种酶很容易被溶液中痕量的Ｍｇ２＋等金属离子激活，从而使溶液中的ＤＮＡ或ＲＮＡ解链或失活．因而用ＮＭＲ方法研究核酸的溶液结构时，需要在磷酸缓冲溶液中加入乙二胺四乙酸（ＥＤＴＡ）或其钠盐，保持其浓度大于０．１ｍｍｏｌ／...

When three dimensional conformations of nucleic acid are studied with NMR methods, EDTA(ethylene diamine tetra acetic acid) or its sodium salt has to be added in the solution in order to protect the nucleic acids from contamination by some metal ions such as Mg 2+ . In this paper, the interaction of d(GGTATACC) 2 and EDTA has been observed in D 2O solution containing 0.05 mmol/L DNA and about 5 mmol/L EDTA. Four pairs of NOE cross peaks connecting the acetic proton( δ 3.64) of EDTA with the protons G 18( δ 7.81), G 11′( δ 5.65), G 13′( δ 4.13) and G 12′( δ 2.54) of d(GGTATACC) 2 observed, suggesting that EDTA may form complex with d(GGTATACC) 2 possibly through hydrogen bond interactions between amino protons in DNA (H2 of G 1 and H4 of C 8) and carbonyl oxygen atoms of EDTA. The interaction of d(GGTATACC) 2 and EDTA may account for NOEs between two DNA oligomers, G 11′(5.65) and C 86(7.47), G 11′( 5.65 ) and C 82′/C 82″(2.18).