Topoisomerase 2A

Accession #/Synonyms: CA09762; ATP hydrolyzing DNA topoisomerase II alfa.

Both prokaryotes and eukaryotes have two major classes of topoisomerases that make transient single- or double-strand cuts in DNA. The first type II topoisomerase was bacterila enzyme DNA gyrase that calalyzes ATP-dependent introduction of negative supercoils into DNA. Human DNA topoisomerase II is essential for chromosome segregation and is the target for several clinically important anticancer agents. It is expressed as genetically distinct alpha and beta isoforms encoded by the TOP2alpha and TOP2beta genes that map to chromosomes 17q21-22 and 3p24, respectively (1).  The Topo2A and beta isofroms display differential tissue expression, withTopo2A is highly up-regulated in proliferating cells. The Topo2A gene consist of 35 exons spanning 27.5kb .  The Top2A comprise of three structural domains associated with energy transduction, DNA breakage-union activity and nuclear localization (1).  The alfa and beta genes differ at the extreme 3’ end suggesting that the two genes are divergent later during evolution. 
Topo2A and B are important therapeutic targets for anticancer drugs such as ectoposides and antibiotics. Topoisomerase-II accumulates at centromeres during prometaphase, where it resolves the DNA catenations that represent the last link between sister chromatids (2).  TopoIIA activity involves an imtermidiate in which the Topo2A is covalently bound to a DNA double-strand  break via 5’-phopshotyrosyl bond which is later cleaved by Tyrosyl-DNA phosphodiesterase 2 (TPD2).  Though these intermediates are transient in nature but they are stabilized by certain anticancer drugs (3). Topo2A is a 1531 aa protein (185kDa).  

Topo2A- selective antibodies were generated against a peptide form unique regions on Topo2A protein corresponding to amino acid 1242-1265 near the C-terminal end of protein. This region was not only antigenic but also lies on the surface of the protein in native or in partially denatured Topo2A confirmation.  The anti-Topo2Aantibodies are fully characterized for applications in western blotting and ELISA at the recommended dilutions.  The Topo2Aantibodies are affinity purified on an immobilized antigen based affinity matrix, the isolated antibodies were then stabilized in antibody stabilization buffer for long-term storage.  FabGennix Int. Inc. provides Topo2A Western blot positive control samples in “ready-to-use” SDS-PAGE sample buffer.  Limited quantities of antigenic blocking peptide for Topo2A antibody is also available, please inquire before ordering.  FabGennix Int. Inc., will also conjugate this antibody to fluorophores and other secondary enzymes at a nominal price.

For research use only, not for diagnostic or therapeutic use.