McConnell B, Hoo D L
Chem Biol Interact. 1982 Apr;39(3):351-62. doi: 10.1016/0009-2797(82)90051-5.
Studies on monomeric cytosine were undertaken to establish a kinetic foundation for the progressive melting of DNA by the mutagen, methylmercury. The reversible displacement of protons by methylmercury at the amino group of cytosine is slow on the 1H-NMR time scale at 100 and 360 MHz. Exchange coupled resonances are produced, not only for all protons of the free- and mercurated amino species, but for the rotational isomers of the latter. These spectra provide for assignment of all exchange-coupled resonances, selection of resonances providing mercuration rates from line shape and measurement of pH-dependent reciprocal lifetimes of the free-amino species (less than or equal to 6 s-1 at pH 3 and 15 s-1 at pH 4). Evidence is presented for the existence of an amino-mercurated species of cytidine thus far not reported (formation constant, 10.
对单体胞嘧啶进行了研究，以建立诱变剂甲基汞使DNA逐步解链的动力学基础。在100和360兆赫的1H-NMR时间尺度上，甲基汞在胞嘧啶氨基上的质子可逆取代反应很慢。不仅产生了游离氨基物种和汞化氨基物种所有质子的交换耦合共振，还产生了后者旋转异构体的交换耦合共振。这些光谱可用于确定所有交换耦合共振，从线形选择提供汞化速率的共振，并测量游离氨基物种的pH依赖性倒数寿命（在pH 3时小于或等于6 s-1，在pH 4时为15 s-）。文中提供了迄今未报道的胞苷氨基汞化物种存在的证据（形成常数为10）。
