A new method for the determination of the relative affinity of a ligand against various DNA sequences by electrospray ionization mass spectrometry. Application to a polyamide minor groove binder

摘要

A new method for the determination of the relative affinity of a ligand against various dsDNA sequences is presented by using electrospray ionization time-of-flight mass spectrometry (ESI-QTOF) mass spectrometry. The principle is described here through the complexation of double-stranded DNA by a polyamide ligand including twelve N-methylpyrrole rings. However this method could be applied to other ligands especially when dissociation constants (K-d) are in nanomolar range. This method does not require knowing the ligand concentration accurately. It allows determination of the relative affinity of a ligand against various dsDNA sequences for 1:1 complex stoichiometries in a quick manner without labeling.