B-Ring-Aryl Substituted Luotonin A Analogues with a New Binding Mode to the Topoisomerase 1-DNA Complex Show Enhanced Cytotoxic Activity
Figure 8
The two binding orientations of compounds 3.
Docking studies revealed two different modes of binding: A. In the case of compounds 3a–e, the docking pose was similar to the one found for topotecan by X-Ray crystallography. B. Compounds 3f and 3g, on the other hand, changed their mode of binding in order to shield the highly hydrophobic dimethylphenyl moiety from the aqueous environment by burying it between the base pairs of the scissile strand and the surface of the protein. C Detail of the newly described binding feature of the human topoisomerase 1-DNA complex uncovered by our study.