Role of the inter-protofilament sliding in the bending of protein microtubules.

This paper aims to identify the role of the inter-protofilament (PF) sliding in the bending of microtubules (MTs). A molecular structural model (MSM) was employed to study the dependence of bending on the inter-PF bonds. It was found that the inter-PF bonds serve as an angle spring that controls the inter-PF sliding during the bending. When the angle spring is soft inter-PF sliding occurs leading to the length-dependent bending stiffness of MTs. Such a size dependent bending stiffness may also affect the vibration and buckling behavior of MTs where bending deformation is predominant.