Probing the interaction of distamycin A with S100 beta: the 'unexpected' ability of S100 beta to bind to DNA-binding ligands

摘要

DNA-minor-groove-binding ligands are potent antineoplastic molecules. The antibiotic distamycin A is the prototype of one class of these DNA-interfering molecules that have been largely used in vitro. The affinity of distamycin A for DNA is well known, and the structural details of the complexes with some B-DNA and G-quadruplex-forming DNA sequences have been already elucidated. Here, we show that distamycin A binds S100, a protein involved in the regulation of several cellular processes. The reported affinity of distamycin A for the calcium(II)-loaded S100 reinforces the idea that some biological activities of the DNA-minor-groove-binding ligands arise from the binding to cellular proteins. Copyright (c) 2015 John Wiley & Sons, Ltd.