Podust L M, Gaìdamakov S A, Abramova T V, Vlasov V V, Gorn V V
Bioorg Khim. 1989 Mar;15(3):363-9.
It is shown that in slightly acidic solution (pH approximately 5.3) reagent CIRCH2NHpT(CT)6 (RCl = -C6H4-N(CH3)CH2CH2Cl) modifies a double-stranded DNA fragment (120 b. p.) containing A(GA)6.T(CT)6 sequence at a single nucleotide residue, viz. G29 located near to this sequence in the DNA chain. The location of this modification point suggests formation of a triple-stranded reactive complex with parallel orientation of the pyrimidine oligonucleotide moiety of the reagent and pyrine sequence of the target DNA. Analysing the modification extent dependence of the reagent concentration the association constant Kx between the reagent and DNA was calculated (Kx = (0.95 +/- 0.03).10(5) M-1, 25 degrees C, pH = 5.3, [NaCl] = 0.1 M). The modification by the reagent ClRCH2NHpT(m5CT)6 has the same quantitative characteristics as in the case of ClRCH2NHpT(CT)6.
结果表明，在微酸性溶液（pH约为5.3）中，试剂CIRCH2NHpT(CT)6（RCl = -C6H4-N(CH3)CH2CH2Cl）在单个核苷酸残基处修饰了一个含有A(GA)6.T(CT)6序列的双链DNA片段（120个碱基对），即位于DNA链中该序列附近的G29。该修饰点的位置表明试剂的嘧啶寡核苷酸部分与靶DNA的嘌呤序列以平行方向形成了三链反应复合物。通过分析试剂浓度对修饰程度的依赖性，计算出试剂与DNA之间的缔合常数Kx（Kx = (0.95 +/- 0.03).10(5) M-1，25℃，pH = 5.3，[NaCl] = 0.1 M）。试剂ClRCH2NHpT(m5CT)6的修饰具有与ClRCH2NHpT(CT)6相同的定量特征。
