Impact of stiffness parameter k on dynamics and validity of analytical approximations

Determine the impact of the inter-dimer stiffness parameter k on the dynamics predicted by the two-component angular microtubule model with W-potential and on the validity of the associated analytical and semi-discrete breather solutions.

Background

The paper develops a two-component angular model of microtubule dynamics based on a W-shaped electrostatic potential, leading via a semi-discrete approximation to an envelope equation of nonlinear Schrödinger type and breather-like solutions. The model parameters include the inter-dimer stiffness k, dipole and field strengths, and potential coefficients A, B, and C.

While most parameters are estimated from biophysical considerations, the authors adopt an assumed value for the stiffness k without a systematic analysis. Numerical investigations indicate that the validity of both semi-discrete and continuous analytical approximations depends sensitively on model parameters. The authors explicitly leave for future work a concrete paper of how k influences the microtubule dynamics and the validity range of the analytical and semi-discrete solutions.