Transformation of Tubulin Architectures by using Cationic Polymer as a Molecular Switch

Abstract

Tubulins heterodimers are pre-programmed biological building blocks. αβ-tubulins are assembled into cytoskeleton microtubules (MTs), which are dynamic protein nanotubes involved in many important cellular functions. During the growth and shrinkage of MTs, the conformational changes of tubulin building blocks occur upon the hydrolysis of nucleotide bound to tubulin. The tubulin assembly is known to be sensitive to various molecules such as MT-associated proteins (ex. Tau), drugs (ex. Taxol), and even cationic molecules (ex. divalent magnesium ions). We show our recent findings on the tubulin architectures in the presence of cationic polymers, in results which play the role as molecular switches. Structures of the assemblies were studied by using synchrotron small angle X-ray scattering (SAXS) and transmission electron microscopy (TEM).