The influence of molecular charges on microtubule curvatures in an electrical field

Toward a novel molecular separation, we propose a method to control gliding directions of microtubules (MTs) using a kinesin-MT system. The directions are controlled by electrical charges of cargo molecules partially labeled on the minus ends of MTs. We designed MTs labeled with streptavidin (SA), nanogold (NG), or dsDNA molecules, and evaluated their curvatures in an electrical field. The curvature of DNA-MT was larger than those of SA-MT or NG-MT because of DNA's large negative charge. These differences of curvatures enable to separate gliding MTs according to their cargo molecules.