This review provides a detailed discussion of recent advances in the medicinal chemistry of
camptothecin, a potent antitumor antibiotic. Two camptothecin analogues are presently …

The nuclear enzyme topoisomerase I (topo I) has been recently recognized as the target for
the anticancer drug camptothecin (CPT) and its derivatives. Two of the agents that target this …

Many intercalative antitumor drugs have been shown to cleave DNA indirectly through their
specific effect on the stabilization of a cleavable complex formed between mammalian DNA …

Using the P4 unknotting assay, DNA topoisomerase II has been purified from several
mammalian cells. Similar to prokaryotic DNA gyrase, mammalian DNA topoisomerase II can …

The purified type II DNA topoisomerase from the embryos of Drosophila melanogaster exists
in its native form as a dimer of 170,000-dalton polypeptides. In addition to the 170,000 …

We investigated systematically the knotting of nicked circular duplex DNA by Escherichia
coli topoisomerase I. Agarose gel electrophoresis of knots forms a ladder of DNA bands …

Topoisomerase I (TopoI), an essential enzyme, produces a DNA single strand break
allowing DNA relaxation for replication. The enzymatic mechanism involves sequential …

The activity of the endogenous DNA topoisomerase type I (EC 5.99. 1.2) can be quantified in
situ by determining how efficiently the enzyme is trapped in a covalent complex with DNA …

The intertwining of the two strands of the DNA helix presents a number of topological
problems which the cell must overcome in order to regenerate, recombine, and express its …

Specialized type I topoisomerases catalyze DNA strand transfer during site-specific
recombination in prokaryotes and fungi. As a rule, the site specificity of these systems is …