Kinetic analysis of human topoisomerase IIα and β DNA binding by surface plasmon resonance

Publisher Website
Google Scholar
Abstract
Topoisomerase IIβ binding to DNA has been analysed by surface plasmon resonance for the first time. Three DNA substrates with different secondary structures were studied, a 40 bp oligonucleotide, a four way junction and a 189 bp bent DNA fragment. We also compared the DNA binding kinetics of both human topoisomerase isoforms under identical conditions. Both α and β isoforms exhibited similar binding kinetics, with average equilibrium dissociation constants ranging between 1.4 and 2.9 nM. We therefore conclude that neither isoform has any preference for a specific DNA substrate under the conditions used in these experiments