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 …

We report the x-ray crystal structure of human topoisomerase I covalently joined to double-
stranded DNA and bound to the clinically approved anticancer agent Topotecan. Topotecan …

Water-soluble analogues of the antitumor alkaloid camptothecin (1) were prepared in which
aminoalkylgroups were introduced into ring A or B. Most of the analogues were prepared by …

Increasing the ability of chemotherapeutic drugs to kill cancer cells is often hampered by a
limited understanding of their mechanism of action. Camptothecins, such as topotecan …

Publisher Summary DNA topoisomerase I (top1) prevents the accumulation of DNA torsional
tension, and its activity is essential for DNA replication, RNA transcription, and also for DNA …

The benzophenanthridine alkaloids nitidine and fagaronine were characterized as inhibitors
of topoisomerase I function. In common with the antitumor agent camptothecin, both nitidine …

A new technique for uncoupling the cleavage and religation half-reactions of topoisomerase
I at a specific site has been developed. The technique takes advantage of a suicidal DNA …

Amino acid sequence comparisons of human topoisomerase I (Topo I) with seven other
cellular Topo I enzymes reveal that the enzyme can be divided into four major domains: the …

Cleavage of a defined linear duplex DNA by vaccinia virus DNA topoisomerase I was found
to occur nonrandomly and infrequently. Approximately 12 sites of strand scission were …

Revised Manuscript Received March 8, 1995® abstract: Camptothecins belong to a group of
anticancer agents with a specific mechanism of action: stabilization and trap** of …