Title of article :
Zampanolide, a Potent New Microtubule-Stabilizing Agent, Covalently Reacts with the Taxane Luminal Site in Tubulin α,β-Heterodimers and Microtubules Original Research Article
Author/Authors :
Jessica J. Field، نويسنده , , Benet Pera، نويسنده , , Enrique Calvo، نويسنده , , Angeles Canales، نويسنده , , Didier Zurwerra، نويسنده , , Chiara Trigili، نويسنده , , Javier Rodr?guez-Salarichs، نويسنده , , Ruth Matesanz، نويسنده , , Arun Kanakkanthara، نويسنده , , St. John Wakefield، نويسنده , , A. Jonathan Singh، نويسنده , , Jesus Jimenez-Barbero، نويسنده , , Peter Northcote، نويسنده , , John H. Miller، نويسنده , , Ju، نويسنده ,
Abstract :
Zampanolide and its less active analog dactylolide compete with paclitaxel for binding to microtubules and represent a new class of microtubule-stabilizing agent (MSA). Mass spectrometry demonstrated that the mechanism of action of both compounds involved covalent binding to β-tubulin at residues N228 and H229 in the taxane site of the microtubule. Alkylation of N228 and H229 was also detected in α,β-tubulin dimers. However, unlike cyclostreptin, the other known MSA that alkylates β-tubulin, zampanolide was a strong MSA. Modeling the structure of the adducts, using the NMR-derived dactylolide conformation, indicated that the stabilizing activity of zampanolide is likely due to interactions with the M-loop. Our results strongly support the existence of the luminal taxane site of microtubules in tubulin dimers and suggest that microtubule nucleation induction by MSAs may proceed through an allosteric mechanism.
