Virtual and biophysical screening targeting the ?-tubulin complex--a new target for the inhibition of microtubule nucleation.

ABSTRACT: Microtubules are the main constituents of mitotic spindles. They are nucleated in large amounts during spindle assembly, from multiprotein complexes containing ?-tubulin and associated ?-tubulin complex proteins (GCPs). With the aim of developing anti-cancer drugs targeting these nucleating complexes, we analyzed the interface between GCP4 and ?-tubulin proteins usually located in a multiprotein complex named ?-TuRC (?-Tubulin Ring Complex). 10 ns molecular dynamics simulations were performed on the heterodimers to obtain a stable complex in silico and to analyze the residues involved in persistent protein-protein contacts, responsible for the stability of the complex. We demonstrated in silico the existence of a binding pocket at the interface between the two proteins upon complex formation. By combining virtual screening using a fragment-based approach and biophysical screening, we found several small molecules that bind specifically to this pocket. Sub-millimolar fragments have been experimentally characterized on recombinant proteins using differential scanning fluorimetry (DSF) for validation of these compounds as inhibitors. These results open a new avenue for drug development against microtubule-nucleating ?-tubulin complexes.

SUBMITTER: Cala O 

PROVIDER: S-EPMC3655011 | biostudies-literature | 2013

REPOSITORIES: biostudies-literature