Characterization of trifluralin binding with recombinant tubulin from Trypanosoma brucei.

The binding kinetics of five novel trifluralin analogs with recombinant alpha- and beta-tubulin proteins from Trypanosoma brucei rhodesiense was determined. Native tubulin from rats was used to determine the extent of binding of each analog to mammalian tubulin. The results of this study clearly demonstrate two important characteristics of the binding of these trifluralins to tubulin. Firstly, they have specific affinity for trypanosomal tubulin compared with mammalian tubulin irrespective of the chemical composition of the trifluralin analog tested. Secondly, they have a stronger affinity for trypanosomal alpha-tubulin compared with trypanosomal beta-tubulin. In addition, compounds 1007, 1008, 1016, and 1017 have strong binding affinities for alpha-tubulin, with limited binding affinity for mammalian tubulin, which indicates that these compounds selectively bind to trypanosomal tubulin.