Visualising the dissociation of sequence selective ligands from individual binding sites on DNA

FEBS Letters

Fox, Keith R.¹  Fletcher, Michael C.¹ 

[1] Department of Physiology and Pharmacology, University of Southampton, Bassett Crescent East, Southampton SO16 7PX, UK

关键词: Echinomycin;    Mithramycin;    Nogalamycin;    Dissociation;   

DOI  :  10.1016/0014-5793(96)00039-7

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

We have used a modification of the footprinting technique to measure the dissociation of mithramycin, echinomycin and nogalamycin from their binding sites in a natural DNA fragment. Complexes with radiolabelled DNA were dissociated by addition of unlabelled DNA. Samples were removed at various times and subjected to DNase I digestion, and the rate of dissociation from each site was estimated from the time-dependent disappearance of the footprints. For echinomycin the slowest rate of dissociation is from ACGT, while the slowest site for mithramycin contains four contiguous guanines. The dissociation of nogalamycin is extremely slow, even from its weaker sites; the slowest rate was from ACGTA, which took longer than 4 h, even at 37°C.

【 授权许可】

Unknown