Bioorthogonal Functionalization of Tubulin with Linear-Zampanolide

Microtubule dynamics plays a critical role in many cellular processes and compounds that affect this process have been the basis of cytotoxic chemotherapeutic agents for many decades. We recently identified linear-zampanolide, a unique analogue that maintains potent cytotoxicity through microtubule stabilization despite significant conformational flexibility. This surprising discovery provides an opportunity to systematically and independently structural features of parent compound to provide new biological probes that covalently bind to tubulin. We will modify the C19-ester to a similarly hydrophobic trans-cyclooctene (TCO) derivative which will allow bioorthogonal tetrazine-TCO click chemical modification of microtubule-bound ligands. The accessibility of the TCO functionality for ligation will be evaluated by the use of the tetrazine-dye conjugates. If successful, these novel TCO-linear zampanolide will become the basis of a new therapeutic strategy through the in cyto generation of dual drug conjugates through bioorthogonal ligation with tetrazine-modified MAPK inhibitors.