The active GTP- and ground GDP-liganded states of tubulin are distinguished by the binding of chiral isomers of ethyl 5-amino-2-methyl-1,2-dihydro-3-phenylpyrido(3,4-b)pyazin-7-yl carbamate

Research was conducted to prove that the active GTP- and ground GDP-liganded states of tubulin are distinguished by the binding of chiral isomers of ethyl 5-amino-2-methyl-1,2-dihydro-3-phenylpyrido(3,4-b)pyazin-7-yl carbamate. Results indicate that the binding of the R- and S-isomers to the GTP-Mg-tubulin generated a protein conformational change which induced a GTPase activity and the formation of abnormal polymers. Findings also demonstrate that a colchicine-site ligand can induce the polymerization of GDP-tubulin into filamentous structures.