The assembly-inducing laulimalide/peloruside a binding site on tubulin: molecular modeling and biochemical studies with [³H]peloruside A.

ABSTRACT: We used synthetic peloruside A for the commercial preparation of [³H]peloruside A. The radiolabeled compound bound to preformed tubulin polymer in amounts stoichiometric with the polymer's tubulin content, with an apparent K(d) value of 0.35 μM. A less active peloruside A analogue, (11-R)-peloruside A and laulimalide acted as competitive inhibitors of the binding of the [³H]peloruside A, with apparent K(i) values of 9.3 and 0.25 μM, respectively. Paclitaxel, epothilone B, and discodermolide had essentially no ability to inhibit [³H]peloruside A binding, confirming that these compounds bind to a different site on tubulin polymer. We modeled both laulimalide and peloruside A into the binding site on β-tubulin that was identified by Huzil et al. (J. Mol. Biol. 2008, 378, 1016-1030), but our m

SUBMITTER: Nguyen TL 

PROVIDER: S-EPMC2996141 | biostudies-literature | 2010 Nov

REPOSITORIES: biostudies-literature