Elastic Network Normal Mode Analysis for Microtubule Mechanics

The cellular microtubules MTs are hollow cylinder-shaped biopolymers with inner and outer diameter of about 17 and 25 nm and length ranging from 1 to 10 μm. They are constituted by αβ-tubulins arranged in protofilaments with a head-to-tail motif [1]. The protofilaments bind together laterally along the MT’s long axis with a slight shift generating a spiral with a pitch of 2, 3 or 4 monomers’ length (Fig.1a). The building-block of the MT, the αβ-tubulin, is a hetero-dimer made of two globular monomers, α- and β-tubulin, each of them consisting of about 450 residues with high degree of sequence similarity from the primary to the tertiary structure level [1].