Mazin A V, Kuzminov A V, Dianov G L, Salganik R I
Institute of Cytology and Genetics, Academy of Sciences of USSR, Novosibirsk.
FEBS Lett. 1989 Dec 4;258(2):244-6. doi: 10.1016/0014-5793(89)81664-3.
It was found that DNA alkylation at the N-7 guanine with the bulky alkylating reagent, N,N,N'-tri-(beta-chloroethyl)-N'-(p-formylphenyl)propylene diamine-1,3 (TFP) is much diminished when DNA is double-stranded. We report here an application of this reaction for probing the hairpin structure in the palindrome-containing single-stranded (ss) DNA fragment of 377 bases prepared from the Eco-RI-BaMHI fragment of plasmid pBR322. 5'-Labeled ss fragment was modified with TFP and cleaved by piperidine hydrolysis at the alkylated guanine residues according to the Maxam-Gilbert procedure. Guanines in the hairpin formed by palindrome of 9 bp were protected from TFP action, while dimethyl sulfate modified all guanines.
研究发现，当DNA为双链时，用大分子烷基化试剂N,N,N'-三-(β-氯乙基)-N'-(对甲酰苯基)丙二胺-1,3（TFP）对N-7鸟嘌呤进行DNA烷基化的程度会大大降低。我们在此报告该反应在探测由质粒pBR322的Eco-RI-BaMHI片段制备的377个碱基的含回文单链（ss）DNA片段中的发夹结构方面的应用。5'-标记的单链片段用TFP进行修饰，并根据Maxam-Gilbert方法在烷基化的鸟嘌呤残基处通过哌啶水解进行切割。由9个碱基对的回文形成的发夹中的鸟嘌呤受到保护，免受TFP作用，而硫酸二甲酯则修饰了所有鸟嘌呤。
