posted on 2019-03-25, 00:00authored byShixin Li, Zengshuai Yan, Zhen Luo, Yan Xu, Fang Huang, Guoqing Hu, Xianren Zhang, Tongtao Yue
Mechanical heterogeneity
is ubiquitous in plasma membranes and
of essential importance to cellular functioning. As a feedback of
mechanical stimuli, local surface tension can be readily changed and
immediately propagated through the membrane, influencing structures
and dynamics of both inclusions and membrane-associated proteins.
Using the nonequilibrium coarse-grained membrane simulation, here
we investigate the inter-related processes of tension propagation,
lipid diffusion, and transport of nanoparticles (NPs) adhering on
the membrane of constant tension gradient, mimicking that of migrating
cells or cells under prolonged stimulation. Our results demonstrate
that the lipid bilayer membrane can by itself propagate surface tension
in defined rates and pathways to reach a dynamic equilibrium state
where surface tension is linearly distributed along the gradient maintained
by the directional flow-like motion of lipids. Such lipid flow exerts
shearing forces to transport adhesive NPs toward the region of a larger
surface tension. Under certain conditions, the shearing force can
generate nonzero torques driving the rotational motion of NPs, with
the direction of the NP rotation determined by the NP–membrane
interaction state as functions of both NP property and local membrane
surface tension. Such features endow NPs with promising applications
ranging from biosensing to targeted drug delivery.