Reaction of dihydropyrrolizines with deoxyribonucleic acids in vitro.
Reaction of dihydropyrrolizines with deoxyribonucleic acids in vitro.
复制标题
二氢吡咯嗪与脱氧核糖核酸的体外反应。
作者：
I. White;A. Mattocks
1. 体外用野百合碱吡咯预处理的大肠杆菌 DNA 在加热过程中的热变性曲线与对照 DNA 样品没有差异。在预处理的 DNA 样品冷却过程中观察到复性程度显着增加。复性程度取决于所用吡咯的浓度。 2. 当用野百合碱吡咯预处理大鼠肝脏 DNA 时，热处理后的复性程度比用大肠杆菌 DNA 的情况要高。 3.在碱性氯化铯中的平衡密度梯度离心表明，与未经处理的对照DNA相比，用野百合碱吡咯和热预处理的DNA在冰中淬火时变性、复性的程度更大。无论DNA用吡咯初始处理1分钟还是15分钟，复性程度相似。该反应似乎与 5.5 至 9.0 之间的 pH 值无关。 4. 反核碱吡咯在交联 DNA 方面与野百合碱吡咯一样有效，但野百合碱吡咯在加入 DNA 之前暴露于水 5 分钟则无效。用合成的双羟甲基吡咯酯预处理大肠杆菌 DNA 也在热处理后引起复性。单酯无效。 5.用逆转录碱处理大鼠后，没有发现肝脏DNA发生交联。
1. Thermal denaturation profiles of Escherichia coli DNA pretreated with monocrotaline pyrrole in vitro showed no difference from control DNA samples during heating. A substantial increase in the degree of renaturation during cooling of the pretreated DNA samples was observed. The degree of renaturation was dependent on the concentration of pyrrole used. 2. When rat liver DNA was pretreated with monocrotaline pyrrole there was a greater degree of renaturation after heat treatment than was found with E. coli DNA. 3. Equilibrium-density-gradient centrifugation in alkaline caesium chloride showed that DNA pretreated with monocrotaline pyrrole and heat denatured, renatured to a greater extent on quenching in ice than did untreated control DNA. The degree of renaturation was similar whether the initial treatment of the DNA with pyrrole was for 1 or for 15min. The reaction also appeared to be independent of pH between 5.5 and 9.0. 4. Retrorsine pyrrole was as effective as monocrotaline pyrrole in cross-linking the DNA, but monocrotaline pyrrole exposed to water for 5min before the addition of the DNA was ineffective. Pretreatment of E. coli DNA with synthetic bis-hydroxymethylpyrrole esters also caused renaturation after heat treatment. Monoesters were ineffective. 5. After treatment of rats with retrorsine, no cross-linking of the liver DNA could be demonstrated.