纺锤菌素与含有重复赖氨酸序列的多肽形成的复合物中纺锤菌素与DNA的结合。

Binding of netropsin to DNA in complexes with polypeptides containing repetitive lysine sequences.

作者信息

Votavová H, Burckhardt G, Sponar J, Zimmer C

出版信息

Biochim Biophys Acta. 1981 Jul 27;654(2):175-80. doi: 10.1016/0005-2787(81)90169-6.

Abstract

The interaction of the antibiotic netropsin with calf thymus DNA, T4 DNA and poly(dA-dT) . poly(dA-dT) in complexes with sequential polypeptides containing repetitive lysine sequences and histone H1 was investigated using circular dichroism spectroscopy and equilibrium dialysis. Both soluble DNA-polypeptide complexes and insoluble complexes showed binding of netropsin. The possibility of displacement of polypeptides from DNA binding sites by competition with netropsin molecules was eliminated by experiments using 14C-labelled polypeptides. From the analysis of CD titration behavior as well as from the results of equilibrium dialysis studies it follows that netropsin does not compete with polypeptides for DNA binding sites, which suggests that these two ligands occupy different sites. Various explanations for minor differences in the CD behavior of the bound netropsin in the saturation region are also discussed.

摘要

利用圆二色光谱法和平衡透析法，研究了抗生素纺锤菌素与小牛胸腺DNA、T4 DNA以及与含有重复赖氨酸序列的连续多肽和组蛋白H1形成复合物的聚（dA-dT）.聚（dA-dT）之间的相互作用。可溶性DNA-多肽复合物和不溶性复合物均显示出纺锤菌素的结合。使用14C标记的多肽进行的实验排除了通过与纺锤菌素分子竞争而将多肽从DNA结合位点置换的可能性。通过对圆二色滴定行为的分析以及平衡透析研究的结果可知，纺锤菌素不会与多肽竞争DNA结合位点，这表明这两种配体占据不同的位点。还讨论了饱和区域中结合的纺锤菌素的圆二色行为存在微小差异的各种解释。