COMSOL models of fluid flow in the sarcomere|肌肉细胞流体动力学数据集|分子机器力学数据集

A highly organized and densely packed lattice of molecular machinery
within the sarcomeres of muscle cells powers contraction. Although many of
the proteins that drive contraction have been studied extensively, the
mechanical impact of fluid shearing within the lattice of molecular
machinery has received minimal attention. It was recently proposed that
fluid flow augments substrate transport in the sarcomere, however, this
analysis used analytical models of fluid flow in the molecular machinery
that could not capture its full complexity. By building a finite element
model of the sarcomere, we estimate the explicit flow field, and contrast
it with analytical models. Our results demonstrate that viscous drag
forces on sliding filaments are surprisingly small in contrast to the
forces generated by single myosin molecular motors. This model also
indicates that the energetic cost of fluid flow through viscous shearing
with lattice proteins is likely minimal. The model also highlights a steep
velocity gradient between sliding filaments and demonstrates that the
maximal radial fluid velocity occurs near the tips of the filaments. To
our knowledge, this is the first computational analysis of fluid flow
within the highly structured sarcomere.