Optical tweezers experiments show melting DNA facilitates the binding of minor groove binder netropsin.

Abstract

Netropsin is an anti-cancer drug that is known to bind in the minor grooves of DNA. There have been many previous studies that explored the binding of this drug to DNA using traditional methods where an ensemble averaging is used. In this study we explore the interaction of Netropsin with DNA using optical tweezers. We trapped and stretched a single DNA molecule using a dual beam optical tweezers to measure the force experienced by the DNA as a function of extension in the absence and presence of various concentrations of Netropsin. The preliminary data suggests that melting of the DNA facilitates the binding of Netropsin at nano-molar range. This exposes more questions that have to be answered through future experiments, which may lead to the better understanding of this drug and could help design better therapeutics.