Kinetic analysis of human topoisomerase IIalpha and beta DNA binding by surface plasmon resonance.
Topoisomerase IIbeta 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 alpha and beta 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.
Leontiou
Chrysoula
C
School of Cell and Molecular BioSciences, The Medical School, University of Newcastle upon Tyne, Newcastle upon Tyne NE2 4HH, UK.
Lightowlers
Robert
R
Lakey
Jeremy H
JH
Austin
Caroline A
CA
D000951:Antigens, Neoplasm; D004247:DNA / Q000378:metabolism*; D004250:DNA Topoisomerases, Type II / Q000378:metabolism*; D004268:DNA-Binding Proteins; D006801:Humans; D007700:Kinetics; D009690:Nucleic Acid Conformation; D011485:Protein Binding; D013379:Substrate Specificity; D020349:Surface Plasmon Resonance
D000951:Antigens, Neoplasm; D004268:DNA-Binding Proteins; D004247:DNA; D004250:DNA Topoisomerases, Type II