Nanobiomechanical Properties of Microtubules

Microtubules, the active filaments with tubular shapes, play important roles in a wide range of cellular functions, including structural supports, mitosis, cytokinesis, and vesicular transport, which are essential for the growth and division of eukaryotic cells. Finding properties of microtubules is one of the main concerns of scientists. This work helps to obtain mechanical properties of microtubule. For this aim, interaction energy in alpha-beta, beta-alpha, alpha-alpha and beta-beta dimers was calculated using the molecular dynamic simulation and GROMACS software package. Force-distance diagrams for these dimers were obtained using the relation between potential energy and force. Each dimer has nearly 8500 atoms. There are more than 100 tubulins in a microtubule with 13 protofilaments and 0.1 µm length. So, molecular dynamic simulation of a microtubule will be a very difficult task. Then, it would be better to build a structural mechanic model which has rather similar properties with microtubule. The first and most important step for this process is to obtain the interaction force between tubulins. Therefore, instead of the each tubulin we can consider one sphere with 55 kDa weights that connect to another tubulin with a nonlinear connection such as nonlinear spring. The mechanical model of microtubule was used to calculate Young’s modulus based on finite element method. The Young’s modulus has good agreement with previous works.