1. A fluorescence anisotropy assay to discover and characterize ligands targeting the maytansine site of tubulin.
- Author
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Menchon, Grégory, Prota, Andrea E., Lucena-Agell, Daniel, Bucher, Pascal, Jansen, Rolf, Irschik, Herbert, Müller, Rolf, Paterson, Ian, Díaz, J. Fernando, Altmann, Karl-Heinz, and Steinmetz, Michel O.
- Abstract
Microtubule-targeting agents (MTAs) like taxol and vinblastine are among the most successful chemotherapeutic drugs against cancer. Here, we describe a fluorescence anisotropy-based assay that specifically probes for ligands targeting the recently discovered may-tansine site of tubulin. Using this assay, we have determined the dissociation constants of known may-ansine site ligands, including the pharmacologically active degradation product of the clinical antibody-drug conjugate trastuzumab emtansine. In addition, we discovered that the two natural products spongistatin-1 and disorazole Z with established cellular potency bind to the maytansine site on β-tubulin. The high-resolution crystal structures of spongistatin-1 and disorazole Z in complex with tubulin allowed the definition of an additional sub-site adjacent to the pocket shared by all maytansine-site ligands, which could be exploitable as a distinct, separate target site for small molecules. Our study provides a basis for the discovery and development of next-generation MTAs for the treatment of cancer. [ABSTRACT FROM AUTHOR]
- Published
- 2018
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