The deamination of cytidine and cytosine by acidic buffer solutions. Mutagenic implications.
The deamination of cytidine and cytosine by acidic buffer solutions. Mutagenic implications.
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酸性缓冲溶液使胞苷和胞嘧啶脱氨基。
DOI：
10.1021/bi00871a026
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发表时间：
1966
期刊：
影响因子：
2.9
通讯作者：
R. Klein
中科院分区：
文献类型：
--
作者：
R. Shapiro;R. Klein
与胞苷的反应速率已被研究并且似乎取决于缓冲液阴离子和质子化胞苷的浓度。在 0.5 m 柠檬酸钠缓冲液中，速率最大的亚硝酸，一种有效的化学诱变剂，通过核酸的腺嘌呤、胞嘧啶和鸟嘌呤残基的氨基脱氨来发挥其作用（Schuster 和 Schramm，1958）。然而，三个碱基受到攻击的事实使得将突变事件与特定化学变化联系起来变得困难。我们一直在研究核酸成分脱氨基的替代化学方法，以开发具有更大特异性的潜在诱变剂。众所周知，在强酸性条件下核酸水解过程中，腺嘌呤、胞嘧啶和鸟嘌呤会脱氨基（Jordan，1960）。我们现已发现，在pH高达5.0的酸性缓冲溶液中，在不使腺苷或鸟苷脱氨基的条件下，胞苷和胞嘧啶可以脱氨基。为了找到该反应的最佳条件，并获得有关机理的信息，我们研究了脱氨基速率对 pH 值以及缓冲液类型和浓度的依赖性。
The rate of the reaction with cytidine has been studied and appears to be dependent upon the con-centration of buffer anion and of protonated cytidine. In 0.5 m sodium citrate buffer, a rate maximum oc-itrous acid, a potent chemical mutagen, exerts its effect by the deamination of the amino groups of the adenine, cytosine, and guanine residues of the nucleic acids (Schuster and Schramm, 1958). The fact that three bases are attacked has made it difficult, however, to correlate a mutational event with a particular chemical change. We have been studying alternative chemical methods of deamination of the nucleic acidcomponents in order to develop potential mutagenic agents of greater specificity. It is known that adenine, cytosine, and guanine are deaminated during the hydrolysis of nucleic acids under strongly acidic conditions (Jordan, 1960). We have now found that cytidine and cytosine can be deaminated, in acidic buffer solutions of pH up to 5.0, under conditions which donot deaminate adeno-sine or guanosine. In order to find the optimal conditions for this reaction, and to obtain information about the mechanism, we have studied the dependence of the rate of deamination upon the pH, and the type and concentration of the buffer.