Baeza I, Gariglio P, Rangel L M, Chavez P, Cervantes L, Arguello C, Wong C, Montañez C
Department of Biochemistry, Escuela Nacional de Ciencias Biologicas del IPN, Mexico, DF.
Biochemistry. 1987 Oct 6;26(20):6387-92. doi: 10.1021/bi00394a012.
We have obtained polyamine-compacted DNA and analyzed it by electron microscopy employing the method described by Dubochet, suitable for the study of complexes in which the main interactions are of ionic character. In addition, we have developed a simple biochemical method, based on the action of pancreatic DNase I, to demonstrate the condensation of DNA with spermidine. DNA-spermidine complexes are resistant to the action of DNase I, and there is a strong correlation between the presence of condensed DNA forms, both as toroids and as cylinders, and the insensitivity to DNase I activity. We have also shown that pBR322 DNA-spermidine complexes are transcriptionally active in the presence of Escherichia coli RNA polymerase. This supports the data concerning the biological activity of spermidine-condensed DNA.
我们已获得多胺压缩的DNA，并采用杜博歇描述的方法通过电子显微镜对其进行分析，该方法适用于研究主要相互作用为离子性质的复合物。此外，我们基于胰脱氧核糖核酸酶I的作用开发了一种简单的生化方法，以证明DNA与亚精胺的凝聚。DNA-亚精胺复合物对脱氧核糖核酸酶I的作用具有抗性，并且作为环形和圆柱形的凝聚DNA形式的存在与对脱氧核糖核酸酶I活性的不敏感性之间存在很强的相关性。我们还表明，pBR322 DNA-亚精胺复合物在大肠杆菌RNA聚合酶存在下具有转录活性。这支持了有关亚精胺凝聚DNA生物活性的数据。
